Abstracts Monday AM, April 19, 1999

4.3

Sessions 4, 8, and 9 4.1 EFFECTS

OF

PHYSICAL

TRAINING

OVER

MYOCARDIAL

PERFUSION, SYSTOLIC FUNCTION AND STRESS TREADMILL VARIABLES. FJ Roldan, E Alexanderson, A Ovando, MF Marquez. D Victoria. lnstituto Nacional de Cardiologia "lgnacio Chavez". Mexico City. MEXICO. Cardiac rehabilitation program after myocardial infarction increases life quality and the angina threshold of the patients. The aim of the study is to analyze the changes in myocardial perfusion, systolic function measured by echocardiography and treadmill variables after a second phase of a rehabilitation program. METHOD: We studied 46 patients with ischemic heart disease. The mean age was 54 years and 90% were males. A dual isotope protocol using 3 mCi rest TI-201 SPECT followed by 20 mCi stress sestamibi injection was performed in all the patients before and after rehabilitation program. Perfusion data were read using 20 SPECT segment analysis and each segment was scored using a 5 points scoring system (0=normal, 4=absent uptake).Summed rest score and summed stress score were obtained. Left ventricle diameters and ejection fraction were calculated by echocardiography. RESULTS: A significant difference was found in metabolic equivalents performed before and after the program (8.8 vs 11.6 METs p < 0.001), pressure response (5.9 vs 6.7 mmHg /MET, p< 0.0081), chronotopic response (8.7 vs 6.7 beats/ MET, p< 0.0046), oxygen comsumption (30.8 vs 41.1 ml/Kg/min, p< 0.00001) and ischemic threshold (5.3 vs 8.9 METS,p< 0.0017). No significant difference was found in the score of myocardial perfusion studies at rest -summed rest score-(18 vs 14, p=0.08) or during exercise-summed stress score- (22 vs 1% p=0.05), left ventricle diameters (systolic 32 vs 35. hnm; dyastolic 51.9 vs 41.3), ejection traction (51.5 vs 50.1), myocardial efficency index (7.9 vs 6.5) and myocardial oxygen comsumptioo (26.8 vs 25.2 ml/min). CONCLUSIONS: Physical training in patients with coronary artery disease increases vital capacity and decrease ischemic threshold. There is a tendency to decrease myocardial ischemia found in nuclear perfusion studies although this variation did not demonstrate statistical significancy.

HYPERVENTILATION FOLLOWED BY NITRATE 99mTc-TETROFOSMINE SCINTIGRAPHY : A SENSITIVE DIAGNOSTIC TOOL FOR VASOSPASTIC ANGAINA PECTORIS Kouten Rin, Hiroshi Yamabe, Atsushi Yamamoto, Makoto Ando, Sei Fujiwara, Mituhiro Yokoyama. The First Department of Internat Medicine, Kobe University School of Medicine, Japan BACKGROUND AND PURPOSE Hyperventilation ECG test is a simple, safe and modestly sensitive diagnostic tool for coronary vasospasm. Myocardial perfusion scintigraphy can improve a sensitivity of the test. Hyperventilation followed by nitrate 99mTc-Tetrofosmine scintigraphy has two advantages; it can freeze a perfusion abnormality during spasms, and nitrate can relieve an increased coronary tone completely at the resting image. We hypothesized that our method enhances a sensitivity of both diagnosis of disease and multivessel spasm. METHODS Eleven patients who complained of resting chest pain underwent both a scintigraphy and a provocative angiography. RESULT Seven of 11 patients showed transient perfusion defect and positive angiographic vasospasm, resulting in sensitivity and specificity calculated at 100% and 100%, respectively. Positive ST change was found in only 3 patients, yielding a sensitivity of 27%. CONCLUSION Hyperventilation followed by nitrate 99mTc-Tetrofosmine scintigraphy is a feasible and highly

sensitive diagnostic approach to vasospastic angina lacking ECG changes. 4.4

4.2 PERFUSION SCINTIGRAPHY DOES NOT UNDERESTIMATE ISCHEMIA IN MULT1VESSEL CORONARY

ARTERY

DISEASE AS SHOWN

BY

SI-

MULTANEOUS ASSESSMENT OF MYOCARDIAL FUNCTION.

Ouhayoun E.; Coca F.; Payoux P & Esquerr6, J.P. M6decine Nucl6aire. H6pital Purpan. Toulouse. France. Myocardial perfusion scintigraphy (SPECT) fairly often shows less severe abnormalities then it would be expected from the angiographic status. The a i m of this study is to compare angiographic and scintigraphic data in evaluation of ischemia severity in patients with multivessels coronary artery disease (CAD). Methods : 67 patients with angiographically proven CAD, 38 with two vessels and 29 three-vessels disease, underwent M I B I SPECT with simultaneous assessment of ventricular f u n c t i o n (LVF) by first pass radionuclide angiography at rest and during stress. According to results of scintigraphy, 3 g r o u p s were created. Group A with normal perfusion, B with 1 territory affected, C with 2 or more. Results : Global CAD detection rate was 80% for stress test, 86% for LVF, 93% for SPECT and 97% for SPECT+ LVF. There no significant difference in stress testing variables and in mean PEF (54.5 vs 48.3%) between the a n g i o g r a p h i c groups. Mean PEF was significatively different between all scintigraphics groups (table below) whereas stress testing parameter failed, excepted ST depression (A vs B&C, p = 0.01).

Ip(Avs )l

I ( vsc)l c Ip(AvsC/I

Groups I A [ mean PEF+sd 171+91 <0,0001 157+111 <0,0001 146+121 <0,0001 I Conclusion : SPECT provides a better correlation with left ventricular function at stress than angiographic data. This results suggest that scintigraphy does not underestimate ischemia in multivessels disease patients. Futhermore, addition of LVF to SPECT provides a better assessment of CAD.

Journal of Nuclear Cardiology January/Febrnary 1999, Part 2

DIAGNOSIS OF PERIOPERATIVE MYOCARDIAL INFARCTION (PM1) USING T C - 9 9 m SESTAMIBI PERFUSION SCAN. E Alexanderson, M Marquez, E Lopez, O Fiscal, A Gutierrez, F Zubiaur, R Alvarado, A Navas, D Lozoya , D Victoria, C Arean, D Bialostozky, J Altamirano. lnstituto Nacional de Cardiologia "Ignacio Chavez" and Panamericana University, Mexico City, MEXICO. PMI is a not uncommon complication from cardiac surgery. Diagnosis of PMI is very difficult because chest pain, enzymes and ECG changes are expected from surgery. PMI can affect dramatically the patient prognosis. The purpose of this study is to evaluate the utility of Tc-99 sestamibi perfusion SPECT for diagnosis of PMI. METHOD: Patients from Intensive Post - Surgical care unit where randomly sent for a rest nuclear scan 1 or 2 days after revascularization surgery with suspicion of PMI (CPK higher than 1000 units, ST - T ischemic changes in the ECG and hemodinamic unstable -Group A- ). All of them had a perfusion scan performed before surgery. Criterion for PMI was the appearance of a new perfusion defect at rest in the study performed after surgery compared with the study done before surgery. To avoid surgery reperfusion effect over myocardial perfusion, we studied a control group (without suspicion of PMI -Group B- ). Perfusion data were read using 20 spect segments analysis and each segments was scored using a 5 score system (0= normal. 4 = absent uptake). Summed rest score (SRS) before and after surgery was obtained. RESULTS:

After surgery * p <0.05 ** p=NS The most frequent location of new perfusion defects were the anterolateral and inferolateral walls. CONCLUSIONS: Tc-99 sestamibi myocardial perfusion SPECT is an useful procedure for diagnosis of perioperative myocardial infarction. It can also identify myocardial infarction location.

S1

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Abstracts Monday morning, April 19, 1999

Journal of Nuclear Cardiology January/February 1999, Part 2

4.5

4.7

PREDICTION

OF

CORONARY

STENOSIS

DEGREE

BY

USING MYOCARDIAL PERFUSION SCAN. E Alexanderson, I Ahoitis, A Zajarias, JL Pohls, A Preciado, D Victoria, D Bialostozky, J Altamirano. lnstituto Nacional de Cardiologia "lgnacio Chavez" and Universidad Anahuac.Mexico City, MEXICO. Coronary stenosis degree (CSD) has a prognostic value in patients with ischemic heart disease. SPECT myocardial perfusion scan can predict the coronary artery responsible for a perfusion defect. The aim of this study is to evaluate if a perfusion scan can predict the degree of coronary stenosis based in the severity of a perfusion defect. METHOD: We studied 202 ischemic patients with one single vessel disease demonstrated by coronariography. A myocardial perfusion scan using rest thallium 201/stress sestamibi dual isotope or one day rest/stress sestamibi protocol was performed in all the patients. Perfusion data were read using 20 SPECT segment analysis and each segment was scored using a 5 points scoring system (0=normal, 4=absent uptake). RESULTS: 1

41% *

2 3 4

76% * 87% * 99% * * p<0.05 Patients with small perfusion defects (score l and 2) had an average of 59 % coronary stenosis degree and patients with important perfusion defects (score 3 and 4) had an average of 92.9% coronary stenosis degree (p < 0.05). CONCLUSIONS: Myocardial perfusion imaging can predict the coronary stenosis degree based in the score of severity of the perfusion scan.

4.6

LAD RCA LCX

21.5' 25.4* 12.5 17.4 12 17.2 * p < 0.008 Conclusions: Despite succesful stenting :l)perfusion defect at rest was present in all patients although reperfusion time influenced the rest defect size,2)LAD occlusion was associated with a larger infarct and ischemic extent,3)stress induced ischemia was frequent and could be extensive.Therefore, for optimal risk stratification,routine SPECT may be beneficial in succesfully stented patients following AMI.

4.8

INTRA-CORONARY STENT IMPLANTATION IN PATIENTS WITH

MYOCARDIAL PERFUSION AFTER STENT IMPLANTATION DURING ACUTE MYOCARDIAL INFARCTION. E Alexanderson, S Maciel , H Kiat, E De La Pefia, G Eid , R Villavicencio, A Puente, J Rubinstein, A Arroyo, D Victoria, D Bialostozky. Instituto Nacional de Cardiologia "Ignacio Chavez".Mexico City, MEXICO and Liverpool Hospital, Sydney AUSTRALIA. The impact of STENT implantation during acute myocardial infarction(AMI) on myocardial perfusion needs to be clarified. Therefore, we analyzed the effect of succesful STENT implantation on myocardial perfusion during AMI. METHOD: 56 patients underwent rest thalliumstress sestamibi dual isotope protocol 3-4 months after the AMI. Perfusion data during rest and stress were analyzed using a 20 SPECT segment evaluation. Each segment was scored using a 5 points scale (0= normal, 4= absent uptake). Summed rest score (SRS) and summed stress score (SSS) were obtained. Angiographic data was also analyzed. RESULTS: All the studies revealed some degree of perfusion defect. SRS was smaller when the STENT was implanted less than 2 hours after AMI (13 vs 23.2, p <0.05). Regional SSS and SRS in LAD territory were larger compared with the oher vessels. Defect reversibility(SSS-SRS) was present in 87% of patientsDR ranged from 3 to 5.

CHRONIC

CORONARY ARTERY DISEASE : TREATMENT SUCCESS USING

EVALUATION OF MYOCARDIAL PERFUSION SPECT. E Alexanderson, H Kiat, A Puente, C Arean, S Nava, J Rubinstein, A Arroyo, D Bialostozky, D Victoria. Instituto Nacional de Cardiologia "Ignacio Ch~ivez". Mexico City, MEXICO and Liverpool Hospital, Sydney,AUSTRALIA. Coronary angioplasty followed by stent implantation(STENT) has been widely practiced in recent years for the treatment of coronary stenosis in patients with chronic coronary artery disease (CCAD). The degree of treatment sucesss was evaluated in this study using rest Tl-201/stress Tc-sestamibi dual isotope myocardial perfusion SPECT(SPECT). METHOD: 26 patients with CCAD underwent successful (achieving TIMI flow > 2, and stenosis of < 50 %) single vessel STENT. SPECT was performed < 2 weeks before and routinely between 3-4 months after STENT. Perfusion data were read using a 20 SPECT segment analysis and each segment was scored using a 5 points system (0=normal, 4 = absent uptake). Summed stress score(SSS), summed rest score (SRS), reversibility extent -RE- (SSS-SRS) and delta RE (pre stent RE - post stent RE) were obtained. These indices were obtained for the total left ventricular myocardium(G) and regionalIy for the territory of the affected vessel (R). RESULTS : G-RE ~ ~ ~ ~ Pre- Stent 8.65 5.6 6 13.5 Post -Stent 7.73 1.3 2.2 10.8 delta RE 10.6 % 76 % 63.3 % 20 % CONCLUSIONS: Significant reduction in ischemic extent was observed 3-4 months following successful STENT. However, in most(62% of patients),stress induced ischemia remains post-STENT indicating incomplete normalization of coronary flow. Pre and post-STENT myocardial perfusion SPECT appears to be clinically useful in the evaluation of treatment success.

DUAL-ISOTOPE MYOCARDIAL SCINTIGRAPHY (REST Tl-201 / STRESS T c - 9 9 m - T E T R O F O S M I N ) TC DETECT REVERSIBLE HYPOPERFUSION A.Peix, A.L6pez, F.Ponce, A.M.Maltas, R. Garcla, J. Barrera, D.Garcla-Barreto. Institute o f Cardiology, Havana, Cuba Dual-isotope technique assesses myocardial perfusion in coronary artery disease patients. So, w e used it for detecting reversible hypoperfusion in 20 patients with prior myocardial infarction and clinical and ergometric signs o f ischemia. A sequential dual-isotope scintigraphy (3mCi rest TI-201 and 25mCi stress Tc-99m-tetrofosmin) with 24-hr Tl-201 redistribution (RD) was performed. Each patient also underwent a stress/4-hr RD/24-hr RD Tl-201 scintigraphy. With the quantitative global analysis a similar reversibility was observed with both protocols; but if 24-hr RD images were considered, the improvement was significant only comparing vs rest TI-201 (75+8% vs 8 I_+9% o f peak activity; p=0,001). Analyzing only the segments with severely reduced uptake (<50% o f peak activity), in both protocols 24-hr RD improved it significantly (p<0,001 vs rest and vs 4-hr RD). We conclude that a sequential dual-isotope rest TI-201 / stress Tc-99m-tetrofosmin scintigraphy is comparable with a stress - RD Tl-201 scintigraphy to detect reversible hypoperfusion; but, in both cases, 24-hr RD image increases its usefulness mainly in severely hypoperfused segments, if quantitative analysis is considered.

Journal of Nuclear Cardiology Volume 6, N u m b e r 1, Part 2

Abstracts Monday morning, Apiil 19, 1999

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4.11

4.9 EFFECTS OF ISCHEMIC PRECONDITIONING ON MYOCARDIAL INFARCT EXTENT :EVALUATION USING MYOCARDIAL PERFUSION SPECT. E Atex~mderson, H Kiat, S Maciel, E De La Pefia, G Eid, R Villavicencio, A Puente, J Rubinstein, D Victoria, A Arroyo, D Bialostozky. lnstituto Nacional de Cardiologia "Ignacio Cbavez".Mexico City, MEXICO and Liverpool Hospital, Sydney, AUSTRALIA. Brief ischemic episodes have been shown to provide a protective effect by decreasing the extent of myocardial damage and myocardial dysfunction. Ischemic preconditioning can be clinically present as brief episodes of angina prior to an acute myocardial infarction (AMI). The goal of the study was to investigate the effect of angina on the extent of myocardial perfusion defects in patients with AMI succesfully treated with primary PTCA and STENT implantation. METHOD: 49 patients were enrolled and underwent rest thallium-stress sestamibi dual isotope protocol 3-4 months after the AMI. Perfusion data during rest and stress were analyzed using a 20 SPECT segment evaluation. Each segment was scored using a 5 points scale (0= normal, 4= absent uptake). Summed rest score (SRS) and summed stress score (SSS) were obtained. Angiographic data was also analyzed. RESULTS: All the studies revealed some degree of rest perfusion defect. 28 patients had > 1 episodes of angina prior to AMI and were compared with 21 patients without previous angina. SRS SSS SRS SSS SRS SSS With Angina 15.50 20.2 19.2 24.6 9 17.6 Without Angina 18.23 22.5 22.4 24.3 14.4 20.5 For patients with angina, the global SRS, LAD and LCX/RCA were 15%,14% and 37% smaller than patients without angina (p=ns) CONCLUSIONS: In this preliminary study, myocardial perfusion SPECT evaluation demonstrated a trend of smaller infarcts in patients with angina compared to those without angina.

STRESS/REST MYOCARDIAL PERPJS ION SPET TO EVALUATE THE EFFICACY OF PERCUTANEOUS lASER ~OCARDIAL RKVASCIKARIZATION G.Rubini, G.Di Giovine, D.Rubini, A.Bortone, A.Tucci, L.de Luca Tupputi, A.D'Ad~abbo Dept Nuclear Medicine-University of Bari Italy This study was designed to evaluate the myocardial perfusion by Stress/Rest 99mTc-MIBI SPET (22 myocardial segment(M~); perfusion: normal, moderate and severe perfusion defect (PD)), after myocardial revascularization by pulsed laser (PTMR) that produced 12 channels (diameter imm, depth 2-5ram) per MS in initial and subsequent follow-up. The 9 pts were studied before, 1,6,12, months (M) after PIMR, all with angina IV class CCA classification, of which 6 previously unde/went aorta-coronary by-pass (CABG) and 3 no longer treatable using with PIEA or CABG. IM S/R MIBI SPET after FIMR showed moderate reversible PD of MS revascularized with~/t ECG stress and synptcms of ischaemia. 6M S/R MIBI SPET showed no PD in 7 pts, and improved myocardial perfusion in 2. In 12M S/R MIBI SPET all revascularized MS were normo perfused. In conclusion the S/R MIBI SPET is reliable technique to evaluate myocardial revascularizaticn by PIMR that is efficacious in pts no longer treatable by other revascularization techniques.

4.12

4.10 RECOGNITION OF MYOCARDIAL ISCHEMIA IN WOMEN USING TL-201/TC-99m SESTAMIBI DUAL ISOTOPE PROTOCOL. S Unzek, E Alexanderson, J Rubinstein, J Serratos, D Motola , D Bialostozky, A Arroyo, D Victoria, J Altamirano. Instituto Nacional de Cardiologia "Ignacio Chavez" and Anahuac University. The diagnosis of myocardial ischemia is traditionally more difficult in women than in men. The clinical examination, electrocardiogram and stress test have limited diagnostic value to recognized myocardial ischemia in women. Myocardial peffusion is a good method for detecting myocardial ischemia in the general population. The purpose of this study is to evaluate the sensitivity of perfusion scan using dual isotope protocol for the recognition of ischemia in women.METHOD: We studied 152 consecutive women with suspicion of ischemia; coronariography was performed in all of them. Patients were studied with rest thallium 201/stress Tc-99m sestamibi SPECT dual isotope protocol . Perfusion data were read using a 20 SPECT segment analysis and each segment was scored using a 5 score system (0=normal,4=absent uptake). A 60% coronary stenosis was considered significant. The results were compared to the ones obtained of a population of 663 men. RESULTS:

°%

~i!

95.39% 96.38% * 90.5% 92.1% * 96.2% 97% * 91% 98% * • p=NS CONCLUSIONS: Dual isotope myocardial perfusion SPECT is a good method for diagnosis of myocardial ischemia in women. There were no significant differences with the values found in the male sex. Global Sensitivity Sensitivity in one vessel Sensitivity in two vessels Sensitivity in three vessels

UTILITY OF PERFUSION SPECT STUDY TO D I F F E R E N T I A T E B E T W E E N I S C H E M I C AND N O N ISCHEMIC CARDIOMYOPATHY. T Colmenares, E Alexanderson, V Varguez, P Lemus, E Becker, J Apolo, J Rubinstein, A Arroyo, D Bialostozky, D Victoria. Instituto Nacional de Cardiologia "Ignacio Chavez".Mexieo City, MEXICO. Coronariography is a routine procedure used to exclude ischemic heart disease in patients with dilated cardiomyopathy (DCMP). The purpose o f this study is to determine the utility of nuclear scan in differentiating ischemic from non ischemic DCMP. M E T H O D : We studied 34 consecutive patients with dilated cardiomyopathy using TI-201/Tc sestamibi dual isotope or one day rest/stress sestamibi protocols. Perfusion data were read using 20 Spect segment analysis and each segment was scored using a 5 score system (0=normal, 4=absent uptake). Summed rest score (SRS) and s u m m e d stress score (SSS) were obtained. Coronariography was performed in all the patients. Patients were divided in 2 groups : Group A with significant coronary artery disease and group B without coronary artery disease. RESULTS : Group A ( n=18 ) Group B ( n=17 )

21.6 9.9 *

29.6 10.8 * * p < 0.05 C O N C L U S I O N S : Nuclear scan is a helpful technique to differentiate ischemic from non ischemic etiology o f dilated cardiomyopathy. Coronariography would be performed only in patients with high RSS and SSS.

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Abstracts Monday morning, April 19, 1999

4.13 M O N D A Y A M A P R I L 19

THE INFLUENCE OF NITROGLYCERIN ON MYOCARDIAL PERFUSION DEFECTS DETECTED IN MYOCARDIAL SPECT. A.Tarkowska, B.Chrapko, T.Widomska-Czekajska, W.Cholewinski, M.Wypych, Medical University, Lublin, Poland. The aim of the study was to check whether therapeutic dose of Nitroglycerin induces any changes in 99mTc Myoview accumulation defects occuring in myocardial SPECT at rest. The test group comprised 17 pts with coronary artery disease(CAD). All pts underwent myocardial SPECT using 2-days protocol. On the first day the examination was performed 1 hr after injection of 740 MBq Myoview 99mTc, at rest. On the second day the pts were given sublinqually 0.5 mg Nitroglycerin and 5 min.later Myoview 99mTc was injected at rest. The SPECT study was started 1 hr after Myoview injection. The first examination, performed in basic conditions, revealed perfusion defects in all patients. The SPECT after Nitroglycerin showed decrease of perfusion defects in 8 pts, increase of these defects in 4 cases and no change in 5 subjects. No relationship was found between changes in Myoview accumulation defects on one hand and LVEF, regional wall motion abnormalities, localisation of perfusion defects, number of involved vessels, as well as degree of coronary artery stenosis on the other. It was concluded that Nitroglycerin administered sublinqually before Myoview 99mTe SPECT at rest is of limited value in evaluating myocardial viability.

Journal of Nuclear Cardiology January/February 1999, Part 2

4.15 9~Tc-TETROFOSMIN AND mI-MIBG IN THE ASSESSMENT OF TRANSMYOCARDIAL LASER REVASCULARIZATION;PRELIMINARY RESULTS. A. Muxi, M. Magrifi~i, FJ. Setoain. M. Josa, J. Pavia, F. P&ez-Villa, X. Bosch, R. Herranz. Clinic Hospital. Barcelona. Spain To investigate the mechanism which produces an early improvement in a high percentage of patients after Trausmyocardial Laser Revascnlarization (TLR), we have studied 9 patients with multivessel coronary artery disease (CAD) refractary to routine treatment angina (class III or IV). We have performed "~l'e Tetrofosmin stress/rest SPET (1 day protoenl) and mI-MIBG (planar) before and at 3 months after TLR, in order to study myocardial perfusion and innervation. We have only considered the segments on which the TLR was performed (n=22). Clinical symptoms were evaluated according to the Canadian Cardiovascular Society (SCC) scale. Perfusiun images (stress/res0 were quantified in polar map using a 9 segment model. MIBG i m a g e s (15 minutes and 4 hours P1) were evaluating using a semiqnantitative score (0-3, normal-non uptake). We have found both at 3 months a significant improvement in clinical symptoms (p<0.005) and a significant worsening in myocardial innervation (p < 0.05). No differences were found in myocardial perfusion. In conclusion, a despite significant clinical improvement and noperfusion changes were observed at 3 months. Further studies in a larger number of cases are warranted to confirm the myocardial mnervation worsening.

4.14

4.16

EFFECT OF TRIMETAZIDINE ON Tc-99m TETROFOSMIN UPTAKE IN PATIENTS WITH CORONARY ARTERY DISEASE. M.Spadafora, A.Cuocolo, M.L.De Rimini, P.Sullo, L.Florimonte, L.Mansi, P.Miletto. University Federico lI, Napoli, Italy. Trimetazidine (TMZ), an original anti-ischemic drug, seems to have a metabolic cytoprotective effect related to mitochondrial function, since it does not induce systemic or coronary hemodynamic changes. This study evaluated the effects of TMZ on Tc-99m tetrofosmin uptake in hypoperfused myocardial regions in patients with coronary artery disease (CAD). Twenty-two patients, 14 with previous myocardial infarction (group A) and 8 with a history of angina (group B), with exercise-induced perfusion defects at stress tetrofosmin tomography and angiographically documented CAD were studied. All patients underwent 2 tetrofosmin SPECT studies at rest, before (control) and after one week of TMZ administration (TMZ study). At quantitative analysis, 131 segments showed a severe exercise-induced defects with absent or incomplete reversibility on rest images. In these segments, tetrofosmin uptake was 51+13% at control and 55+-15% at TMZ study (p<.00l vs control). In the 86 hypoperfused segments of group A, tetrofosmin uptake was 48+14% at control and 52+-17% at TMZ study (p<.001 vs control). In the 45 hypoperfused segments of group B, tetrofosmin uptake was 56+-9% at control and 60+-10% at TMZ study (p<.001 vs control). In the remaining 309 segments no significant difference in tetrofosmin uptake before and after TMZ was observed. These results suggest that TMZ may increase myocardial uptake of tetrofosmin in hypoperfused regions at rest in patients with CAD, according its metabolic effect. The use of tetrofosmin tomography associated with TMZ administration may represent a useful technique for the detection of myocardial viability.

M Y O C A R D I A L 1-123 M I B G S C I N T I G R A P H Y IN N O R M A L SUBJECTS: Q U A N T I T A T I V E A N D SEMIQUANTITATIVE APPROACH. D. Fournet, E. Fleury, P. Delafontaine, A. Righetti. Cardiology, University Hospital, Geneva, Switzerland. In order to assess normal regional values and r e p r o d u c t i b i l i t y o f M I B G cardiac (H) scan, 34 (18W,16M, 30 +_ 8 y) healthy subjects undervent planar (P) and S P E C T (S) studies at 15' and 240'. Semi-quantitative results of P ( H / m e d i a s t i n u m a c t i v i t y ratio) and S (activity of 3 m y o c a r d i a l segments normalized by total activity over 5 medial short axis slices) were: P:1,83 +__ 0,18 and S: 1,00 _+ 0,06). Variability (CV %) of P and S in 10 subjects (2 scans at > 2 months interval) was good (P: 7 % and S: 4 %), with slightly better results at 240'. For S quantitation, blood activity reported to LV cavity was used, yelding a mean (activity/m1) variation of 22%. Conclusions: This results show that analysis of SPECT images is superior to planar ones to determine M I B G uptake. Quantitation by our method shows large CV %, resulting mainly from difficulty to determine LV cavity activity. This data bank of normal values will be useful for comparison with images of patients with suspected cardiac disease.

Journal of Nuclear Cardiology Volume 6, Number 1, Part 2

4.17 THE EFFECTS OF LONG-TERM RIGHT VENTRICULAR APICAL PACING ON CARDIAC SYMPATHETIC INNERVATION: AN 1123 METAIODOBENZYLQUANIDINE (MIBG) SCINTIGRAPHIC STUDY V. Prassopoulos, E. Simantirakis, S. Chrysostomakis, S. Koukoulaki, M. Kanakaraki, P. Vardas, N. Karkavitsas. Heraklion University Hospital, Creta, Greece.

The aim of this study was to investigate whether there are MIBG scintigraphic abnormalities in paced patients where the ventricular stimulus originates from the apex of the right ventricle and is fully paced. We studied 11 patients, 68+8 years, who had been paced in DDD mode for a long period (3.6+1.1 years) (Group A) and 8 patients, 69+9 years, with a recent pacemaker implantation (40_+17 days) (Group B). Twelve healthy individuals, 63+11 years, served as a control group. All patients underwent planar and SPECT myocardial imaging 4 hours after intravenous injection of 5mCi I123-MIBG. The heart to mediastinum (H/M) ratio was calculated in order to quantify cardiac MIBG accumulation, while the SPECT study was performed in order to investigate the regional distribution of adrenergic innervation (Al). All Group A patients underwent a SPECT T12°1 myocardial study. The H/M ratio was less in Group A than in Group B (p<0.01) or the controls (p<0.001). In Group A, 9/11 patients had a regional alteration in adrenergic innervation, compared with 0/8 from Group B (p<0.01). Also, 9/11 patients in Group A had abnormal MIBG SPECT studies, while only 3/11 had a positive TI TM SPECT study in the same areas (p<0.05). In conclusion long term stimulation from the apex of the right ventricle appears to lead to disturbances of adrenergic innervation of the ventricular myocardium. This provides another reason to seek alternative pacing sites which could ensure a more normal activation sequence.

Abstracts Monday morning, April 19, 1999

4.19 PROGNOSTIC SIGNIFICANCE OF 1-123 MIBG CARDIAC IMAGING FOR PREDICTING FUTURE CARDIAC EVENTS: A 10-YEAR FOLLOW-UP STUDY K. Nakajima, J. Taki, M. Shimizu, H. Hirase, EH. Hwang, T. Higuchi, I. Matsunari, N. Tonami, Kanazawa University Hospital, Kanazawa, Japan 1-123 MIBG abnormality in hypertrophic cardiomyopathy (HCM) has been reported and correlated to the severity of HCM. However, long-term prognostic significance of MIBG study in predicting future cardiac events remains unknown. The patients comprised HCM (n=22) in whom both 1-123MIBG and TI-201 imagings were performed in 1988-89. Myocardium was divided into 9 segments, and the defect was scored visually from point 0 (normal) to 3 (defect). A ratio of heart-to-mediastinum (H/M) and washout rate (WR) were calculated from 20-minute and 3-hour images. Changes in cardiac contractility was evaluated by echocardiography. In the 10-year follow-up, cardiac events were observed in 6 patients, i.e., atrial fibrillation/flutter, congestive heart failure, ventricular tachycardia and sudden death. This cardiac event group (n=6) showed significantly higher MIBG defect score (20--.6 vs 11_+5), TI-201 defect score (11-+6 vs 4-+3) and WR (26-+2 vs 21-+7)compared with event-free group. The patients with MIBG defect score >15 (n=10) on delayed image showed a higher incidence of cardiac events and increase in NYHA functional class (5/10), compared with patients with defect score
4.18

4.20

Seintigraphic determination of improvement of myocardial adrenergic nervous activity after treatment with metoprolol in patients with congestive heartfailure.

A U T O N O M I C NERVOUS S Y S T E M (ANS), P E R F U S I O N AND M E T A B O L I S M IN P A T I E N T O P E R A T E D O N F O R T E T R A L O G Y O F F A L L O T (TOF). P.Zanco, L.Daliento, M.C.Baratella, L.Menti, A.F.Folino, F.Chicrichetti. Nuclear Medicine - PET Center, Castelfranco V., Italy. After a mean follow-up of 18+6 y, 22 patients operated on for TOF, underwent II23-MIBG SPECT (MS) and planar LAO 45 ° (MP1) at 30' and 5 h, N13-NH3 PET (PP) and F18-FDG PET (MP). With regard to MP1, a wash-out index (WI=30'/5h myocardial uptake ratio) and a heart/mediastinum ratio at 5 h (HMR) were calculated both for the right and the left ventricle wall. Regarding the SPECT and PET studies a severity index (SI), concerning the extension and the severity of the uptake defects, was calculated. Standard deviation of the RR intervals (SDNN) and % of consecutive RR intervals increasing >50msec (pNN50) were analyzed on 24h Holter monitoring. The 6 patients that presented major ventricular arrhythmias (VA) showed: 1) higher MIBG-WI both in the right and in the left ventricle (p<0.05) and higher MIBG-SI (p<0.01); 2) increased HMR of the right ventricle; 3) no significant difference was found in PP- and MP-SI; 4) both pNN50 and SDNN appeared, correlated to HMR (p<0.005). In conclusion our study suggests that TOF operated patients at risk of VA presented abnormalities in the myocardial ANS, not correlated to perfusion and metabolism damages.

A. de Groot, P. de Milliano, K. I. Lie, B. van Eck-Smit Academic Medical Center, Amsterdam, The Netherlands Myocardial ~23I-MIBG uptake is reduced in cardiomyopathy resulting from both a reduced re-uptake 1 and increased release of norepinephrine (NE) from adrenergic nerve ending. We hypothesized that improvement of myocardial adrenergic nervous system integrity is reflected by a favorable MIBG uptake. 60 consecutive patients (pts) with stable CHF class II or III and an EF < 35 % entered the study after measurement baseline parameters. 55 pts tolerated 50 mg or more with a maximum of 150 mg metoprolol and of 37 pts all parameters were acquired. MqBG washout was deterrn~,ed by planar imaging at 1 and 3 hours post injection and MIBG uptake was determined from SPECT imaging 4 hours post njection of 185 MBq of mI-MIBG. Placebo N=8 Metoprolol N=29 baseline 8 months baseline 8 months MIBG 904-44 824-26 87±46 103±56* NE 3.74-1.7 4.24"3 3.54-2.1 3.84-2.3 EF 27±6 28-4:9 26a:9 32~9 * EDD 70~4 714-6 74±10 674-10* Washoutheart% 354-7 33±4 31±6 32~6 Washoutmediast% 27±6 244-8 274-14 254-9 Washoutlung% 33±5 134±7 314-10 33±6 Results expressed as mean ±SD. *= p< 0.05 MIBG=myocardialuptake (eounts/voxel), NE(nmol/1) EF=ejectionfraction(%), EDD=end di~sto!ic diameter(mm). Conclusion. Improved neuro hurnoral funtion induced by treatment with metoprolol is reflected by improved myocardial MIBG uptake rather than by MIBG washout.

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M O N D A Y A M A P R I L 19

Abstracts Monday morning, April 19, 1999

Joumal of Nuclear Cardiology January/February 1999, Part 2

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4.23

Heart Failure : The Sympathetic Nervous System and Fatty Acid. Jun-ichi Yamazaki : First Department of Internal Medicine, Toho University, School of Medicine, Tokyo, JAPAN

1-123 MIBG SPECT IN ACUTE CORONARY SYNDROMES: COMPARISON WITH AREA AT RISK. I. Matsunari, U. Schrickc, U. Haase, E Bengel, P. Barthel, G. Schmidt, M. Schwaiger. Technische Universitgit Miinchen, Germany.

Patients with heart failure show signs of sympathetic dysfunction, including an elevation in blood nor -epinephrine(NE) levels and down-regulation of 13receptors. The reported changes in these patients include a reduction in number of sympathetic nerve endings in cardiac sympathetic nerves, a decrease in myocardial NE content, accelerated NE turnover or spillover due to poor retention, and NE re-uptake disorder at sympathetic nerve endings. In patients with heart failure, 1-123 MIBG, with a similar chemical structure to NE, was found to be useful in the evaluation of severity and prognosis. We performed MIBG myocardial SPECT in DCM cases and compared the MIBG findings with LVEF. A significant correlation was detected between the MIBG defect and LVEF for both the early and delayed images. Washout rate (WR)was elevated in the LV wall as a whole, with a particularly high regional WR in the inferior wall. A significant correlation was also noted between WR and LVEF. Similarly, the reduction of 1-123 BMIPP uptake correlates with ATP concentration is observed in damaged myocardium. Also, a good correlation was observed between BMIPP defect and LVEF. In comparison of MIBG and BMIPP findings, there was a good correlation. MIBG defect were significantly larger than BMIPP defect. These results suggest that MIBG and BMIPP myocardial SPECT were both useful for evaluation of severity, and disturbance of cardiac sympathetic nerve system appeared before myocardial fatty acid metabolism in patients with DCM.

The aim of this study was to test the hypothesis that sympathetic neuronal damage measured b y 1-123 metaiodobenzylguanidine (MIBG) imaging would reflect risk area in 12 patients undergoing reperfusion therapy for acute coronary syndromes. The risk area was assessed by Tc-99m sestamibi (MIBI) SPECT prior to reperfusion, and infarct size was measured by follow-up MIBI SPECT 1 week later. All patients also had MIBG SPECT (30 min after i.v.) during subacute phase. The image analysis was based on a semiquantitative polar map approach. Defect size on the MIBG or MIBI SPECT was measured for the left ventricle (LV) using a threshold of -2.5 s.d. from the mean value of a normal database, and was expressed as %LV. The MIBG defect size (47-+18 %LV) was larger than the infarct size (27-+23 %LV, p<.01), but was similar to the risk area (49-+18 %LV, n.s.). The MIBG defect size was closely correlated with the risk area (r=.905, p<.01). Furthermore, there was a close agreement between the location of MIBG defect and risk area (93%). Thus, MIBG defect is larger than infarct size, and is closely related to risk area, supporting the concept that sympathetic nerves are more sensitive to acute ischemic injury than myocardial tissue.

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4.24

LINKAGE BETWEEN 123I_MIBGWASHOUT RATE AND AUTONOMIC NERVE REGULATION DURING EXERCISE IN CHRONIC HEART FAILURE M.Ando, H.Yamabe, A.Yamamoto, K.Rin, S.Fujiwara, M.Yokoyama.The First Department of Internal Medicine, Kobe University School of Medicine. Japan. B a c k g r o u n d : The relation between I123-metaiodobenzylguanidine (MIBG) and heart rate variability has not been clarified. The study assessed the linkage between I123-MIBG and autonomic nerve regulation during exercise in chronic heart failure (CHF). M e t h o d s : Seven patients with mild CHF underwent a rest I123-MIBG scintigraphy and a cardiopulmonary exercise test with fixed work load (20W) for 6 minutes. At resting condition and during exercise power spectral analysis of heart rate variability was measured. Parameters were washout rate of I123-MIBG, low frequency (LF) component and high frequency (HF) component of power spectrum, and heart rate response during exercise. R e s u l t s : There was a significant correlation between washout rate of I123-MIBG and increase in heart rate from rest to exercise (r =--0.76, p<0.05). Significant correlation was also found between washout rate of I123-MIBG and the change in LF from rest to exercise (r =0.80, p<0.05). C o n c l u s i o n : The study clarified that washout rate of I123-MIBG represents a reserve to drive autonomic nerve during exercise in patients with CHF, that is, fast washout rate of I123-MIBG links to diminished regulatory change of autonomic nerve system.

MYOCARDIAL [mI]-METAIODOBENZYLGUANIDINE (MIBG) UPTAKE IS DIFFERENT IN PARKINSON'S DISEASE (PD) AND MULTIPLE SYSTEM ATROPHY (MSA) WITH AUTONOMIC FAILURE. F. Courbon*, C. Brefel-Courbon**,M.J. Alibelli*, I. Berry*, O. Rascol**, J.L. Montastrue**,J.M. Senard**. *Servicede Mrdecine Nuelraire, **Service de Pharmacologic Clinique, Centre d'Investigation Clinique H6pitaux de Toulouse. France Autonomic dysfunction is frequently observed in the course of idiopathic PD and of MSA. Several indirect arguments suggest that the mechanism of autonomic nervous system dysfunction are different in these two extrapyramidal disorders. MIBG, a guanethidine analogue, is well-known to be taken up by neuroendocrine cells and sympathetic nerve endings. The aim of this study was to investigate the post-ganglionic sympathetic function in patients with autonomic failure related to PD or MSA using 123I-MIBG myocardial scintigraphy. We performed ~23I-MIBGscintigraphy in 11 patients (5 PD et 6 MSA) without myocardial ischaemia. All patients suffered from autonomic failure were investigated by usual clinical maneuvers and cathecholamine plasma levels changes during standing. The ratio of m1 MIBG uptake in the heart to the upper mediastinium (H/M) was analysed on planar seintigraphic data 30, 120, 240 minutes after mIMIBG injection. MSA patients showed a normal myocardial 123I-MIBGuptake (mean +/-sem H/M= 2.45+/-0.4 at 240 minutes) and this ratio increased from 30 to 240 min. By contrast, in PD patients, the mean H/M was significantly lower (1.26+/-0.2 at 240min) p<0.05 and remained stable from 30 to 240 min. These preliminary results demonstrate a myocardial post-ganglionic sympathetic dysfunction in PD with autonomic failure. ~23I-MIBG cardiac scintigraphy could be of interest to differentiate MSA from PD in patients with parkinsonism and autonomic failure. This work is in progress in a large number of patients

Journal of Nuclear Cardiology Volume 6, Number 1, Part 2

Abstracts Monday morning, April 19, 1999

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4.27

SCLERODERMA HEART DISEASE. A CAUSE OF MYOCARDIAL ADRENERGIC DENERVATION.STUDY BY P2Z-MIBG J. Lekakis, M. Mavrikakis, N. Sifakis, V. Prassopoulos, T. Athanassoulis, S. Gerali, P. Kostamis, S. 8tamatelopoulos. Department of Clinical Therapeutics, ((Alexandrm) University Hospital, Athens, Greece

Cardiac involvement is common in scleroderma and often is clinically unsuspected. Abnormalities of myocardial adrenergic innervation may appear early in the course of myocardial diseases and can be detected by P23-MIBG imaging. To assess possible alterations in adrenergic innervation in patients with scleroderma without evidence of heart failure we examined 9 patients (8 females, 1 male, age 55.7+9 years disease duration 11+4.7 years) by 1123-MIBG imaging; 5 mCi 112a-MIBGwere injected and planar as well as SPECT imaging was performed 4 hours later. Heart to mediastinum ratio (H/M) was computed to quantify cardiac MIBG accumulation. 23 subjects without heart disease served as controls (age 55 + 18 years, ns). In control subjects H/M ratio was 2.13+0.2 (range 1.75 to 2.6). A cutoff point of less than 1.73 (normal mean minus 2 standard deviations) was used to define abnormal study. Patients with scleroderma presented a lower HIM (1.83+0.17, p<0.001); 4 patients presented abnormal HIM ratio (_<1.73). In SPECT MIBG imaging 6/9 patients presented segments with abnormal adrenergic innervation. In conclusion patients with scleroderma present myocardial adrenergic abnormalities, even without evidence of heart failure, which may represent an early sign of myocardial involvement.

4.26

123I-BMIPp/2°lT1 DUAL SPECT IN ACUTE CORONARY SYNDROME T.Kadokami, H.Momii, T.Fukuyama. Matsuyama Red Cross Hospital, Matsuyama, Japan It has been shown that myocardial accumulation of ~23I-BMIPP is decreased in compared to flow tracers in isehemie but viable region. To determine the clinical implication o f ~zsI-BMIPP imaging, 123I-BMIPPP°1T1 dual SPECT followed by left ventrieulography (LVG) and coronary arteriography (including spasm provocative test if there was no stenosis) was performed in 69 patients (pts) suspected acute coronary syndrome. Regions with discrepancy of accumulation between the two tracers (mismatch) were considered to be responsible for isehemic event. Mismatch was observed in 32 o f 48 pts with significant stenosis and 6 of 13 pts with spasm, respectively. All the regions with mismatch were corresponded to the stanotic or spastic lesions. Its sensitivity, specificity, and accuracy to detect isehemie event were 62%, 88%, and 65%, respectively. Coronary revaseularization was operated in 37 of those pts with stenosis. LVG and 2°lTl SPECT were repeated after the treatment. Improvement of left ventricular wall motion after revascularizafion was observed in 11 of 17 pts (65%) with mismatch and in 2 of 5 pts (40%) without mismatch. Z°lTl uptake recovery was observed in 12 o f 15 pts (80%) with mismatch and in 3 of 6 pts (50%) without mismatch, respectively. In conclusion, although ]23I-BMIPp/2°~T1 dual SPECT is a useful tool to assess myocardial regional viability, its ability to predict myocardial functional recovery after revaseularization is limited because o f the relatively low sensitivity in detecting viable tissue.

4.28

SYMPATHETICDYSAUTONOMIA AS A CAUSE OF CEREBRAL HYPOPERFUSION AND MYOCARDIAL NEUROCARDIOGENIC SYNCOPE.

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J.AItamirano, D. Bialostosky,A. Kostine, D. Arteaga, I. Martinez,D. Gonzfilezand A.G. Hermosillo. Deparments of Nuclear Cardiology, Electrophysiotogy and Neurology. Instituto Naeional de Cardiologia Ignacio Chavez e Instituto Nacional de Investigaciones Nucleates. MEXICO. Neurocardiogenic syncope is a common clinical entity with altered cerebral perfusion. Cerebral and myocardial sympathetic dysautonomia as an ethiopatogenic mechanism is suggested. Method: Six females with syncope and spontaneous positive tilt-table testing were studied. Age 1835 years. None had cardiac or cerebral disease. Tilt-testing was performed monitoring continous blood pressure, ECG and Doppler ultrasonography. During fainting, cerebral perfusion SPECT with 99mTc-Bicisate and cardiac SPECT scintigraphy with 13 I I.MIBG images were performed in each patient. SPECT myocardial perfusion rest/stress with sestamibi was also performed 10 days later. Results: In 5 patients the Doppler and the cerebral perfusion images showed generalized severe arteriolar vasoconstriction at the mid cerebral arteries, predominantly left sided. But one patient developed with minimal Doppler variations, important SPECT cerebral left frontal lobe hypoperfusion. Its maximal myocardial uptake of 1311-MIBG (24 hrs later) was abnormal at the left ventricular antero-septal and infero-lateral basal wall. Myocardial perfusion stress test showed ischemia at the inferior wall,with normal perfusion at the anterior wall. In contrast the MIBG and myocardial rest/stress perfusion study were normal in the remaining 5 patients. Conelusion: Adrenergic dysfunction increases microvascular tone and sensitize small cerebral and coronary arteries to vasoconstriction stimuli and may play a role in the ethiopatogenesis of a subset of patients with neurocardiogenic syncope.

Acute Imaging In P a t i e n t s With C h e s t Pain, a N o n d i a g n o s t i c Electrocardigram and Normal Cardiac E n z y m e s . A.Allam, S.Allam, O.AbdElsatar, S.Rady, S.Shaker, H.EIGindy, M.Mansour, M.Salama. AL-AZHAR Uni., Cairo, EGYPT. F o r t y s e v e n p a t i e n t s (pts) w e r e i n j e c t e d a t r e s t d u r i n g c h e s t p a i n w i t h t e c h n e t i u m - 9 9 m S e s t a MIBI. Age 4 8 . 7 + 10 y r s , 2 5 p t s w e r e f e m a l e s , r i s k f a c t o r s 1.6 + 1.2. N o n e o f p t s h a d p r e v i o u s MI. Follow u p p e r i o d (FU) 74.2 + 7 7 . 6 d a y s . D u r i n g F U 8 e v e n t s (EV) o c c u r r e d 3MI, 3PTCA a n d 2 CABG. A 10 w e e k s (wks) EV r a t e of 17%. T w e n t y s e v e n p t s h a d a n e g a t i v e (-ve) a c u t e i m a g i n g (AI) EV r a t e 3 . 7 % "1 MI'. While, 2 0 p t s h a d a p o s i t i v e (+ve) AI EV r a t e 3 5 % " 2 MI, 3PTCA a n d 2 CABG " 1 1 / 1 9 w i t h +ve AI h a d c o r o n a r y a n g i o g r a p h y all h a d s i g n i f i c a n t CAD, n u m b e r o f v e s s e l s 2.1 + 0.89. 2 0 / 2 7 p t s w i t h - v e AI h a d a 3 w e e k s t r e s s p e r f u s i o n s c a n (StrP). All S t r P w e r e - v e . A m o n g c l i n i c a l a n d i m a g i n g d a t a m u l t i v a r i a b l e a n a l y s i s i n d i c a t e s t h a t a +ve AI is t h e o n l y c o r r e l a t e o f EV d u r i n g F U p = 0 . 0 0 4 . I n c o n c l u s i o n , p t s w i t h +ve AI h a s a 9 fold i n c r e a s e in EV t h a n p t s w i t h -ve AI. M o s t p t s w i t h - v e AI h a v e ve 3 w k s StrP. P t s w i t h +ve AI h a v e s e v e r e CAD requiring early revascularization.

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4.29 M O N D A Y A M A P R I L 19

Journal of Nuclear Cardiology January/February 1999, Part 2

4.31 Non Invasive Assessment of The Outcome of Acute PTCA using Radionuclide Imaging

Waheed Radwan; Alia Abd EI-Fanah; Mohamed Ashraf Tamer; Ahmed Abd EI-Aal; Helmy EI-Ghawaby; Ayman EI-Naggar; Ahmed Abd EI-Aziz; Sherif Mokhtar, MD

Objective: To validate the use of single photon emission computed tomography perfusion imaging in early assessment of the success of primary and rescue PTCA. We studied 15 patients (pts), all are males, with acute MI with a mean age of 464-12 years, admitted to Critical Care Department within 6 hours of the onset of chest pain. (MI was anterior in 13, inferior in 1, and lateral in one pt). Following admission, all pts were subjected to clinical evaluation, 12-lead ECG, serial serum CPK, CK-MGB and co-agulation profile, then I5 mci of Technitium sestamibi was given 1.V. and the first set of SPECT images was acquired to assess the segments of myocardium at risk (MAR) before moving to the catheter laboratory. Coronary angiography was done aiming at identification of the infarct-related artery, and visualization of intracoronary thrombus, with anatomically suitable lesions, PTCA and stenting were done, and within 24 hours, a second set of SPECT images was acquired to estimate the infarct size (IS) and the extent of myocardial salvage. In addition, a second look by coronary angiography was done to assess patency, degree of residual stenosis and possible complications. TIMI flow was assessed before and after PTCA. MAR and IS were quantified by application of 13 segments scoring system and the extent of myocardial salvage was estimated by the score difference between the 2 sets of images. Salvage index (SI) was calculated as score difference/MAR. Successful reperfusion was considered with SI exceeding 30%. In our pts, the mean value of MAR was 394-8 (range, 25 to 53), IS: 124-7 (range, 2 to 28), Sl: 694-16 (range of SI: 33-95%). T1M1flow before PTCA was 0 in 14 pts, and 1 in one pt. Post PTCA, TIMI flow became 3 in 12 (80% ofpts), 2 in 2 pts (13% of pts), 1 in one pt (6%) and this pt had thelowest Slby scintigraphy (33%). The acute success rate was 94%, & mean residual stenosis was 12% (range 0 to 20). Hospital mortality rate was 6%, and complications occurred in 3 pts. Conclusion: Non invasive scintigraphic assessment correlates with arteriographic evidence of patency of infarct related artery.

Role Of Acute Perfusion Imaging In Assessment Of Success Of Reperfusion By Throublolytic Therapy Alia Abd EI-Fattah, MD Critical Care Medicine Department, Cairo University, Egypt Objective: To validate the use of perfusion imaging in assessment of reperfusion and patency of infarct related artery in the evolving phase of acute MI to guide the management strategy. We studied 3 8 p t s admitted to critical care department within 6 hours of onset of chest pain of first attack of acute MI. Mean age was 464-11 y (30 males). MI was anterior in 29, inferior in 7, and lateral in 2 pts. All pts were subjected to full clinical examination, 12-lead EKG, serial cardiac enzymes CPK, CK-MB and coagulation profile, then injection of 15 mCi Tc-sestamibi I.V. before any therapeutic intervention. Then 1,500,000 IU of streptokinase was given over one hour. Acquiring the 1st set of SPECT images (which reflects the myocardium at risk (MAR) was delayed untill the pt is hemodynamically stable but within 3 hours from admission, then immediately, a second bolus of Tc-sestamibi (25-30 mCi LV.) was given and acquizition of 2na set of SPECT images to estimate the final infarct size (IS) was done. MAR and IS were quantified by application of 13 segments scoring system (3-0) in I st and 2nd sets of images. Myocardial salvage was estimatedas, salvage index (SI) = score difference/MAR. SI > 30% was an indication for successful thrombolysis. All pts were subjected to coronary angiography within one week to correlate scintigraphic evidence of successful reperfusion to angiographic evidence of patent infarct related artery. Paitnets were divided into two groups: (GrI) pts with SI > 30% i.e. successful reperfusoin) (30 pts), GrlI: Pts with SI < 30% failed reperfusion) (8 pts) who were moved to the cath lab. and then subjected to rescue PTCA. In Gr 1: Mean MAR was 31.54-10.9, initial final scores, infarct size (IS) and SI were: 26.54-4.2, 33.77:53.2, 13.64-7.8 and 59.574-17.56. Timiflow was 2.3 in 28 pts and 0 in 2 pts. In Grll: Mean MAR was 38.54-8 initial, final scores, IS, SI were: 23.8±3.1, 26.54-3.4, 31.64-8.5, 17.54-13.8. Timiflow was 0 in all pts. Conclusion: Early assessment of infarct related artery status in the acute phase of MI could be achieved non invasively by acute perfusions imaging with a sensitivity of 93% and sepcificity 100%. Selection of pts for rescue PTCA can be guided by successive acute perfusion imaging.

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4.32

REST REVERSE REDISTRIBUTION IN ACUTE REPERFUSED MYOCARDIAL INFARCTION : SIGNIFICANCE OF POST-INJECTION TL-SPECT IMAGES. M. Faraggi, D. Kadla-Cohen, R. Lebtahi, N. Delahaye, L. Sarda, R. G6nin, N. Gazzar, PG Steg, D. Le Guludec, Bichat Hospital, Pads, France.

IDENTIFICATION OF MYOCARDIAL ISCHEMIA IN AREAS .OF NORMAL PERFUSION BY REST-DUAL ISOTOPE SPECT WITH F18 DEOXYGLUCOSE AND TC99M SESTAMIBI IN PATIENTS WITH UNSTABLE ANGINA A.Hashimoto, A.Fischman, M.Moroi, G.Zervos, H.Gold, T.Yasuda. Massachusetts General Hospital, Boston, USA.

Rest TI reverse redistribution (RR) was studied 8 days after acute reperfused myocardial infarction in 33 TIMI-3 patients. Post-injection and redistribution images on day 8 (D8) were compared to those obtained on day 42 (D42), to acute microvascular perfusion assessed by intra-coronary myocardial contrast echocardiography (MCE) in the acute phase (16 segment, 3 grade perfusion score) and to late functional recovery on D42 assessed by 2D echocardiography. TI defect size was expressed in % of the whole myocardium after a bull's eye polar map. A marked significant RR was found on day 8 (absolute change: 7.5+7.9% of the 10 min=post-injection defect size, p<5.10-6) and significantly decreased on day 42 to 2.7+6.8%, (p=0.004 between day 8 and 42). The 10 min-post injection defect size best predicted the final infarct size on day 42 evaluated with thallium on D42 and 2D echocardiography (both r=0.8,p<10 3) and was closely related to microvascular perfusion : patients with adequate reperfusion had smaller post-injection defect on day 8 (21.1+14.6%) and a larger reverse redistribution (10.2:1:6.1%) than patients with no reflow (35.3+13% and 3.2:1:9.2%, respectively, p<0.04 for both). Conclusion: The early post-injection scans on day 8 were the relevant images for assessing myocardial salvage and predicting wall motion recovery.

A myocardial region supplied by a significantly stenosed coronary artery often demonstrates normal rest perfusion, e v e n in p a t i e n t s (pts) w i t h u n s t a b l e a n g i n a ( U A ) . It h a s b e e n unknown whether the areas of normal perfusion with recent repetitive ischemia show focal myocardial FDG uptake. We i n v e s t i g a t e d t h e d i a g n o s t i c v a l u e o f F D G u p t a k e in a r e a s o f normal rest-MIBI perfusion for identifying significant d o r o n a r y s t e n o s i s ( > 5 0 % ) in U A p t s . 8 5 U A p t s ( 6 4 + 1 1 years, 58M/27F) with coronary lesions (mean stenosis 85 +17%) underwent rest-dual isotope SPECT with FDG and MIBI under fasting condition. The left ventricle was divided i n t o 7 s e g m e n t s . F o c a l F D G u p t a k e w a s d e m o n s t r a t e d in 1 8 0 o f 4 7 3 s e g m e n t s in a r e a s o f n o r m a l M I B I p e r f u s i o n ( > 8 0 % o f n o r m a l ) , in 4 9 o f 5 2 s e g m e n t s in a r e a s o f r e d u c e d M I B I p e r f u s i o n ( 5 0 - 8 0 % o f n o r m a l ) , a n d in 3 5 o f 7 0 s e g m e n t s i n areas of MIBI perfusion defects (<50% of normal). Out of t h e s e 1 8 0 s e g m e n t s s h o w i n g e n h a n c e d F D G u p t a k e in a r e a s of normal MIBI perfusion, 128 (71%) were associated with significant coronary lesions, and the remaining 52 (29%) had normal coronary a r t e r i e s . In U A pts, s e n s i t i v i t y a n d specificity of FDG MIBI SPECT for detecting coronary s t e n o s i s in a r e a s o f n o r m a l p e r f u s i o n at r e s t w e r e 8 7 % (128/147) and 84%-(274/326). Our results support a unique c l i n i c a l u s e f u l n e s s o f r e s t - F D G M I B I S P E C T in U A p t s .

Journal of Nuclear Cardiology Volume 6, N u m b e r 1, Part 2

4.33 M Y O C A R D I A L ISCHEMIA INDUCED BY OBSTRUCTIVE SLEEP APNEA IN T H E M O R B I D L Y O B E S E W I T H O U T K N O W N HEART DISEASE D E M O N S T R A T E D BY (SPECT) Tc 99m S E S T A M I B L P R E L I M I N A R Y R E P O R T Drs. A Orea, V Rebollar, M Valencia, M Rosales, A Castafio, C

Keims, J Dorantes, S Ley, G Garcia, J Oseguera, O Gonzalez, J Gonzfilez. Instituto Nacional de la Nutrici6n "Salvador Zubirfin", Mexico City. Obesity is an independent cardiovascular risk factor often associated with obstructive apnea (OA), during which cardiac arrhythmias (CA) occur that can cause sudden death. Obiective: To determine whether the CA associated with OA could be attributed to cardiac isehemia we designed this experience. Materials and Methods: We studied 55 patients with OA indexes from 5 to >100 with polysonmography for 2 nights each. On the second night SPECT was performed with a stress/resting protocol considering an apnea episode as the stress phase. Those cases with abnormal SPECT underwent a new SPECT while awake on another day. Coronary angiography was performed when both gammagrams were abnormal. Results: Only 8 patients could be studied by SPECT because of weight <130 kg (maximum limit of our devise). SPECT showed moderate to severe perfusion defects in 100% with an average of 5.5 affected segments/patient corresponding to anterior descending artery in 53%, right coronary in 31% and circumflex in 17%. The waking SPECT had alterations of perfusion involvingonly 2.1 segments/patient. Conclusions: 1) In spite of technical limitations, 100% of the cases studied showed apnea induced ischemia. 2) SPECT is a highly sensitive procedure for detection of myocardial isehemia induced by OA. 3) Incomplete angiography study limited evaluation of specificity.

4.34 ACCURACY AND CONVENIENCE OF LEFT VENTRICULAR FUNCTION MONITORING BY NON-IMAGING NUCLEAR PROBE IN PATIENTS WITH ACUTE CORONARY SYNDROMES. C.Silenzi - N.Ciampani - M.Mazzanti - C.Costantini - G.Cianci - A.Purearo Department of Cardiology - Laneisi Heart Hospital - Ancona (Italy) Left ventrienlar function evaluation is very important in clinical setting for risk stratification and guiding treatment in patients (pts) with coronary artery disease. Cardioscint T M (Oakfield Instruments Ltd, Oxford, UK) is a previously described non imaging nuclear probe system capable of continuous online monitoring of left ventrienlar function using a miniature detector positioned on the chest. We have obtained a very good correlation between Cardioscint and echocardiographic data in terms of evaluation of left ventricular systolic function and diastolic filling measurements. The aim of the present study was to verify accuracy and convenience of the Cardioscint monitoring in patients with acute coronary syndromes (ACS). We studied l 2 pts (8males and 4 females, mean age 58,7a: 16,4 years) admitted to Coronary Care Unit for ACS. No valvular or congenital disease was present neither arrbythmias at the time of acquisition. The nuclear probe held over the left ventricle by an elasticated harness to pts of different body sizes and configuration. Each pt was undertaken to 30 minutes Cardioscint monitoring, after one hour of intravenous injection of pyrophosfate 20 mCi of 99TC. We evaluated: end-diastolic volume, end-systolic volume, ejection fraction, peak filling rate, one-third filling fraction. In 2 pts changes in left ventrienlar function during Cardioscint monitoring preceded symptoms, electrocardiographic and echocardiographic signs of myocardial ischemia and dysfunction. One pt had temporary left ventrieular dysftmetion in the absence of symptoms. The monitoring was widely acceptable and completed in all. In our small population of pts with ACS the left ventricula function monitoring with nuclear probe showed good accuracy and convenience. The low cost of the system may make it affordable in most departments and it may play an important investigative and etinical role in cardiology.

Abstracts M o n d a y morning, April 19, 1999

$9

4.35 ASSESSMENT OF GLOBAL AND REGIONAL LEFT VENTRICULAR FUNCTION A F I ~ R REPERFUSION THERAPY USING Tc-99m SESTAMIBI GATED SPECT IN PATIENTS WITH A C U T E MYOCARDIAL INFARCTION. Y.Nakazawa, S.Takenaka,H.Suyama, K.Shirota, N.Shiode, Y.Goto,K.Inoue, N.Nakamura, H.Katou, Y.Isoda, K.Masui Matsue Red Cross Hospital, Matsue, Japan. Tc-99m sestamibi gated SPECT was performed on patients with AMI, to evaluate myocardial perfusion and wall motion. All patients underwent gated SPECT in the acute and convalescent phases. SPECT data were evaluated by %uptake relative to the peak value. LV was divided into 17 segments in total. From a gated SPECT, we calculated end-diastolic and end-systolic volume(EDV,ESV), ejection fraction(EF) and %uptake at the end-diastole and the endsystole. Regional wall motion was evaluated under a 5point score system. A comparison between the acute and chronic phases revealed that EDV and ESV were reduced, and EF increased. Wall motion abnormalities improved and the %uptake improved in the infarct related area. The gated SPECT confirms that reperfusion therapy improved LV function and wall motion. The results suggest that the gated SPECT enables us to evaluate not only the improvement of myocardial perfusion, but also global and regional left ventricular cardiac function in the AMI.

4.36 CURRENT TRENDS IN RESEARCH ON WORKRELATED ISCHEF~C

SYNDROME

DISORDERS

IN THE URANIUM WORKERS IN BULGARIA. RISK ASSESSMENT. D.Apostolova, Z.Paskalev. Center of Occupational diseases. Sofia,Bulgaria The study aims to give the information on the relationship between ischemic syndrome in the uranium workers and work environment. The connections between the ischemic syndrome of uranium wormers and ther physical environments need to be examined together in order to accurately assess and predict health problems arising from work environmental factors. Work environmental health risk (ischemic syndrome) arise from toxic chemicals, radioisotopes, ionizing and nonionizing radiations and other hazardous materials in uranium industrse. The results show increase the ischemic syndrome about uranium workers in comparison with the mean data for bulgarian people.

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4.37 M O N D A Y A M A P R I L

19

EFFECTS OF a- and J3-ANTAGONISTS ON THE ISCHEMIAINDUCED INCREASE IN FDG UPTAKE IN THE ISOLATED RAT HEART MODEL. N. Nguyen, S. Egert, M. Schwaiger. Technische Universit&t M0nchen, Germany It has been shown that ischemia induces a translocati0n of the glucose transporter, Glut4, resulting in an increase in FDG uptake during reperfusion. The purpose of this study was to investigate whether the catecholamine release during ischemia is responsible for the ischemia-induced enhancement of glucose utilization. Isolated rat hearts underwent retrograde perfusion containing FDG. All hearts were perfused without additives for 15 minutes as baseline, then subjected to 15min no-flow ischemia with reperfusion, with/without propranolol or a-phentolamine. Propranolol or phentolamine alone did not significantly affect baseline FDG uptake. FDG uptake (mean+sd, ml/g/min) Baseline Reperfusion p-value Ischemia 0.022+0.012 0.070+0.012 0.0002 Isch+Propran. 0.014+0.008 0.060+0.004 0.004 Isch+Phentol. 0.015+0.003 0.038+0.012 0.02 Although neither antagonists completely abolished the ischemia-induced increase in FDG uptake, phentolamine significantly reduced FDG uptake during reperfusion compared to ischemia alone (p=0.003), while propranolol did not (p=ns). These data suggest the involvement of the c~-adrenergic mechanism in the ischemia-induced upregulation of FDG uptake. Further pharmacologic studies with specific cO-, c~2antagonists are necessary in order to further clarify the role of the c~-adrenergic system in the regulation of glucose metabolism in ischemic heart disease.

4.38 CONSEQUENCES OF FAMILIAL AMYLOID POLYNEUROPATHY (FAP) IN CARDIAC AUTONOMIC NERVOUS SYSTEM. N. Delahaye, S. Dinanian, R. Genin, T. Fourme, J. Delforge, P. Merlet, M. Slama, D. Le Guludec. Bichat hospital, Paris, France. FAP is a rare hereditary form of amyloidosis including a progressive autonomic neuropathy. Heart failure is uncommon, but sudden deaths, arrhythmias and conduction disturbances occur. Cardiac autonomic nervous system was studied in 10 FAP patients (43 + 14 yrs) with normal coronary arteries and left ventricular systolic function. Presynaptic sympathetic (~) cardiac denervation was assessed by 123-I-MIBG scintigraphy. Postsynaptic parasympathetic (pT.) status was evaluated by PET with 11C-MQNB (methylquinuclidinyl benzilate), a specific antagonist of muscarinic receptors (MR). All results were compared with 12 age-matched control subjects (CS). MIBG uptake was markedly decreased in pts compared to CS (heart-tomediastinum activity ratio at 4 hrs: 1.36 ± 0.21 vs 1.98 ± 0.35, p<0.001). The mean MR density was higher in pts compared to CS (44 ± 18 vs 25 ± 8 pmol/ml, p<0.005). The increase in heart rate (HR) after injection of MQNB, an equivalent of atropine, was lower in pts compared to CS despite a similar basal HR (AHR: 9 ± 19% vs 54 ± 36%, p<0.01). The loss of nerve integrity in FAP results in both X and pX changes with decrease in presynaptic catecholamine stores and upregulation of cardiac MR.

Journal of Nuclear Cardiology January/February 1999, Part 2

4.39 SYMPATHETIC

REINNERVATION AFTER HEART

TRANSPLANTATION - E F F E C T O N

OXIDATIVE

F.Bengel, P. Ueberfuhr, S.Ziegler, S.Nekolla, B.Reichart, M.Schwaiger. Nuklearmedizinische Klinil~ TU Muenchen, Munich, Germany METABOLISM

It has b e e n previously s h o w n that sympathetic reinnervation o f the myocardiurn does occur late after orthotopic heart transplantation (HTX), but remains incomplete. Currently, however, little is k n o w n about the physiologic relevance. In the present study, 14 symptom-free patients underwent P E T 6.5_+3.5 yrs after H T X to determine regional and global influence of myocardial reinnervation on oxidative metabolism. A retention of >7%/rain for C-11 h y d r o x y e p h e d d n e as index o f reinnervation was found in 13 of the 14 patients. The area of reinnervation ranged from 0 to 66 % (mean 23+_19%) of the left ventricle. Global oxidative metabolism, measured b y C-11 acetate and the konstant k(mono) was not different from a group of 10 agematched normals (.06_+.01 after H T X vs .06_+.02 for normals, p=.94), correlated with the rate pressure product (r=.58; p<.03), but did not correlate with the area o f reinnervation (r=-.08; p=.80). Additionally, a regional comparison of k(mono) in reinnervated and denervated myocardium did not reveal a significant difference (.060_+.010 vs .061_+.011, respectively; p=.15). Thus, no direct relationship between myocardial sympathetic reinnervation and oxidative metabolism could be found, suggesting that sympathetic innervation does not play a major role for regulation of oxidative metabolism at rest.

4.40 EVALUATION OF AN EXPERIMENTAL MODEL OF CHRONIC LEFT VENTRICULAR DYSFUNCTION. L. Mesotten, M. Szilard, A. Maes, J. Nuyts, G. Bormans, T. de Groot, M. Borgers, I. De Scheerder, L. Mortelmans. Gasthuisberg, University Hospital Leuven, Belgium. Purpose: The aim of the study was to develop a non surgical animal model of coronary stenosis Presence of viability in areas of chronic dysfunctional myocardinm was investigated. Methods: Stenosis of the LAD in pigs (Sus Scrofa, weight 20-25 kg) was produced using different stents (copper or stainless steel), stent coatings (bare or polymer coating) and methods causing vascular injury (balloon overstretch and/or oversized stent implantation). These factors were combined in different ways during the evaluation of the model. Quantitative coronary angiography (QCA) was used to determine the degree of coronary stanosis. To evaluate the development of myocardial dysfunction, 2D echo was performed before and weekly after stent implantation. One week after the development of hypokinesia, dobutamine stress echocardiography (DSE) and positron emission tomography (PET) were performed to assess myocardial viability. Finally histologic evaluation (HIS) was performed. Results: 21 pigs which developed severe coronary stenosis and wall motion abnormalities were investigated. The copper stent and the combination of balloon overstrctch and a non-coated oversized stent led to myocardial infarction (non viable group). The stenosis in the viable group was caused by implantation of an oversized bare, non-coated stent and b' )lantationof a ,l},mercoated stainless steel stent. N

HIS

PET (%5:SD)

ECHO QCA FS~'%:kSD)J WT(%+SD3 I DSE i DS(Y~I:SD) 18 viable 865:5 90+7 205:4 245:6 biphasicreaction 905:11 3 nonviable 525:9 635:12 135:7 105:7 nochan~es 74+17

Nm]m~

I

PETNH3:meannermalisedNH3uptakein the LADregion;PET FDG:mean normalisedFDGuptakein the LADregion;FS: fractionalshortening;WT: wall thickeningin the LAD region;DS: diameterstanosis Conclusions:A non-surgical porcine model of chronically depressed function in the presence of viable myocardium was successfully developed and evaluated.

Journal of Nuclear Cardiology Volume 6, Number 1, Part 2

4.41 HEAD-TO-HEADCOMPARISON OF "C-ACETATE AND 1sO2 PET FOR MYOCARDIAL OXYGEN UTILIZATIONIN MAN. H.Ukkonen, C.Katoh, L-M.Voipio-Pulkki, M.J.Knuuti, H.Sipil/i, M.Terfis,K.Nhgren, P.Lehikoinen, H.Iida. Turku PET Center, Turku, Finland.. The myocardial clearance constant kmoooof nC-acetate (Ace) is used to estimate cardiac oxygen utilization (MMRO2) with PET. Recently a kinetic method has been developed to measure MMRO2 direedy with inhaled Js O 2. We performed dead to head comparison of the two methods in 13 patients with stable coronary artery ~sease an.d old myocardial infarction. Resting C~50, H~50 and t) 2 studies were lmmediatel followed by Ace study The 150 based kinetic studies yiel%d regional blood flow (rMBi~, ml/min/g) and rMMRO 2 (ml/min/g) which was compared with k~o~oon segmental basis. Segments with rMBF_>75% of maximal r/~gF measured in the patient were considered as normal, segments with rMBF_>50% but <75% of maximum were considered as border segments and segments with rMBF <50% of maximum were considered as low-flow segments. The rMMRO2 was significantly different (p<0.001) in the normal (0,085+0.021 ml/mirdg, mean4-SD), in the border (0.065*0.021ml/min/g) and in the low-flow (0.0444-0.014 ml/min/g) segments. Measured rMMRO 2 and k~o~o correlated well when all the segments were analyzed (r=0.79, p<0.001). However, the ratio of k~rMMRO2 was significantly higher in the low-flow segments than in the border segments or in the normal segments (1,285 0.418 vs. 1.095+0.328 and 0.9414-0.183, p<0.001, respectively). We conclude that, ~502 PET was feasible and accurate for .assessing absolute regional myocardial oxygen consumption both m non-intarcted and infarcted myocardium. Furthermore, ~o,o of ~C-acetate seems to overestimate myocardial oxygen consumption in low-perfusion areas.

Abstracts Monday morning, April 19, 1999

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4.43 QUANTITATION OF CARDIAC VOLUMES USING GATED POSITRON EMISSION TOMOGRAPHY J Freiberg, JD Hove, T Fritz-Hansen, KF Kofoed, S Holm, U HOst, C Meyer, B Hesse, H Larsson, O Paulson, and H Kelbmk. The Heart Centre, Rigshospitalet, Copenhagen, Denmark Quantitation of cardiac volumes from gated FDG positron emission tomography (PET) may provide additional diagnostic information in the assessment of myocardial viability. We therefore developed a new model-based tool for the calculation of cardiac volumes using gated PET and FDG. Methods: A semiautomatic computer algorithm based on profile analysis was developed to derive myocardial coordinates. The fitting algorithm was applied on 36 radial profiles for each plane. For each profile 5 parameters were estimated: The position of the endo- and pericardium, the blood pool, the myocardium and the extracardial background activity. Cardiac volumes were calculated using Simpsons rule. The performance of this model was first tested using a heart phantom, and subsequently tested using gated PET images from thirteen healthy subjects. The PET derived cardiac volumes were compared with cardiac volumes quantitated by gated MRI. Results: PET volume data were within 0.5% of the know phantom values. The mean difference (_+SD) between PET and MRI was -2.4ml (+15ml) for diastolic volumes, -2.8ml (+_10ml) for systolic volumes and 1% (+8%) for EF calculations. Conclusion: Using a model-based approach, measurement of cardiac dimensions with PET and FDG seems accurate and reliable in normal volunteers.

4.42

4.44

C O M P A R I S O N OF F A C T O R A N A L Y S I S AND VISUAL IMAGE ANALYSIS FOR THE DETERMINATION OF CARDIAC OUTPUT USING POSITRON EMISSION T O M O G R A P H Y (PET) JD Hove, KF Kofoed, S Holm, C Wu, L Friberg, J Aldershvile, C Meyer, B, Hesse, and H Kelb~ek. The Heart Centre, Rigshospitalet, Denmark

PET MYOCARDIAL PERFUSION IMAGING WITH CU-62 BIS(THIOSEMICARBAZONE) AGENTS. JL Lacy, NG Haynes, N Nayak, CJ Math±as, MA Green. Proportional Technologies, Houston, USA. The PET agent Cu62 PTSM produced by an automated Zn62/ Cu62 generator yields high quality rest/ dipyridamole(r/dipy) myocardial perfusion images, but exhibits a significantly lower stress/rest myocardial ratio(l.35) than NI3 ammonia(l.65), and a high liver/ heart ratio of 2.0. This study explored the new agents Cu62 ETS and Cu62 nPrTS, designed to reduce albumin binding thought to attenuate high flow uptake. R/dipy PET studies were performed with generator-produced Cu62 ETS (n=5) and Cu62 nPrTS(n=2) in volunteers who previously had r/dipy Cu62 PTSM. The stress-rest myocardial ratios for PTSM and ETS were 1.35 ±0.16 and 1.58±0.11, respectively (p=0.03). N-PrTS shewed a stress-rest ratio of 1.44 ±0.35 compared to 1.42±0.18 for PTSM (p=n.s.). Liver/heart ratios for both agents were ~i.0. Thus, the new generatorproduced agents provide greatly improved liver contrast and likely will provide defect contrast similar to that of NI3 ammonia.

Recently we showed that cardiac output (CO) can be accurately estimated with N-13 ammonia and PET from a factor analysis derived right ventricular input function and the amount of injected tracer (Stewart-Hamilton principle). In this study we evaluated a simplified approach calculating CO from a manually derived right ventricular input function. M e t h o d s : In 13 patients undergoing right sided cardiac catheterisation, the vigilance system (BaxterTM) for continuous cardiac output measurement was mounted. With this catheter in situ a N-13 ammonia PET scan was performed. During the scanning period, the cardiac output was continuously registered using the thermal filment pulse delievering system. Right ventricular input function was calculated using factor analysis and by manually assigning regions of interest (ROI) to the right ventricle. Subsequently the area under the input function was calculated for estimation of the CO. Results: The mean difference (+ SD) for ROI vs. Baxter were 1.5 l/rain _+1.5 l/min (p<0.006) and 0.004 l/rain _+0.8 l/min (p=NS) for Factor analysis vs. Baxter. C o n c l u s i o n : Cardiac output determination with PET and a simple ROI assigning approach appears to be biased. In addition, there is a considerable variability in the individual measurements.

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4.45 REPRODUCIBILITY OF M Y O C A R D I A L BLOOD FLOW ASSESSMENT WITH NITROGEN 13 A M M O N I A POSITRON EMISSION T O M O G R A P H Y USING A VOLUMETRIC SAMPLING A P P R O A C H K.Odaka, S.Nekolla, B.J~iger, F.Bengel, S.Ziegler, M.Schwaiger. NuklearmedizinischeKlinik, TUM, Mfinchen, Germany. Positron emission tomography (PET) with N-13 labeled ammonia has been shown to provide quantitative values for regional myocardial blood flow (MBF) under rest andstress conditions. We have developed a volumetric analysis with automatic motion correctiontool and sought to test its value in terms of accurate reproducibility for clinical utility. N- 13 ammonia/PET studies were perfbrmed at rest and during adenosine infusion in twelve cases with coronary artery disease. Two investigators analyzed dynamically acquired data. Time-activity curves for tissue tracer activity were obtained using the newly developed tool. A threecompartment model and curve-fitting algorithm were used to determine estimates of M B F in 13 myocardial regions. The inter- and intraobserver correlation for M B F was excellent(r>0.9). In conclusion, highinter- andintraobserver reproducibility suggests that this volumetric analysis with a high spatial resolution may result in a further improvement of the reliability of dynamic N- 13 ammonia studies.

4.46 MICROVASCULAR DYSFUNCTION IN HEART DISEASES: SIMILAR IMPAIRMENT OF THE MICROCIRCULATION TO DIFFERENT ETIOPHATOGENETIC STIMULI. A.Giorgetti, D.Neglia, G.Sambuceti, N.Nista, O.Parodi. CNR Institute of Clinical Physiology, Pisa, Italy. Recent reports showed that a coronary microvascular dysfunction may impair myocardial blood flow (MBF) in various heart diseases. Whether the severity of MBF abnormalities are depending on the specific heart disease or on the underlying microvascular disorder is still unknown. To this purpose we measured, by means of PET, baseline and dipyridamole MBF in patients with isolated coronary stenosis of the left anterior coronary artery (LAD, 31 pts), dilated cardiomyopathy (DCM, 33 pts, EF= >.30, <.50) essential hypertension (H, 27 pts, myocardial thickness <1.2 cm) and in 15 controls. All patients belonged to a NYHA class I-II. The analysis was performed in the lateral wall of the left ventricle in order to minimize the effect of coronary stenosis in LAD pts. Coronary reserve (dipyridamole/ resting MBF) resulted similarly (p=ns) impaired in the 3 category of patients (LAD=2.08_.63; DCM--2.04+.78; H=2.36+.94) and significantly lower than that obtained in controls (3.62+1.75, p<.001). Minimal resistances (mean arterial pressure/dipyridam01e MBF) were similar among the patients (LAD=70+_21; DCM=78+_40; H=74_+41 mmHg/mL*min ~*g-~) and significantly higher with respect to controls (28+__8 mmHg/mL*min-~*g f, p<,001), kn conclusion, our data suggest that, in patients with different heart diseases and comparable clinical conditions, a coronary microvascular dysfunction may cause similar MBF abnormalities.

Joumal of Nuclear Cardiology January/February 1999, Part 2

4.47 Regional Myocardial Perfusion and Microvaseular Resistance is Affected by Pacing Frequency in Patients with Sick Sinus Syndrome M. Bottcher, ZC. Nielsen, T. T. Nielsen, H..R. Andersen. Department of Cardiology B and the PET Center, Aarhus Univeristy Hospital, Denmark

Myocardial perfusion (MP) is regulated mainly by changes in the microvascular resistance. Changes in MP have been studied after drugs with effects on both heart rate and contractility e.g. dobutamin. It is not clear however, whether pacing per se and changes in pacing frequency changes regional MP. Pacing will tend to shorten the diastole and thereby time allowed for perfusion. On the other hand pacing will increase perfusion demand. Fourteen patients (72_+4 years) with Sick Sinus Syndrome and implanted pacemaker (AAI or DDD) were studied. Patients were studied at rest and after changing their pacing frequency from rest [50-70] to 90 BPM. MP was measured using dynamic PET and N-13 ammonia. MP was measured in the anterior (ANT), posterior (PST) and septal (SPT) area of the left ventricle. The rate pressure product RPP was calculated as RPP = (Heart rate * Systolic blood pressure). Vascular Resistance (VR) was calculated as VR~(MAP/MBF (mmHg/ml/g/min)). *P<0.01 vs. rest, P<0.05 vs. average MP, Data are Mean_+SD MP ANT

MP PST

MP SPT

CVR

Rest 0.55_+0.14 0.56+0.19 0.49_+0.12 161_+44 Pacing 0.77_+0.22* 0.72+_0.24* 0.70+0.16" 124+31" RPP increasedafter pacing (7577_+1445 vs. 12020_+2674,p<0.001) In conclusion Myocardial perfusion seems reduced in the septal area in patients with pacemakers.Increasing pacing frequency from rest to 90 BPM decrease vascular resistance and increases myocardial perfusion. The increase in perfusion is proportionateto the increase in rate pressure product.

4.48 MYOCARDIAL BLOOD FLOW DECREASES DURING MENTAL STRESS INDEPENDENT OF VASODILATOR CAPACITY/SEVERITY OF CAD. J, Arrighi, M. Burg, I. Cohen, D.J. Bremner, B. Zaret, R. Soufer. Yale University-VA PET Center, West Haven, CT, USA. The pathogensis of mental stress-induced myocardial ischemia (MSI) is incompletely understood. In order to determine the contributions of epicardial coronary disease, coronary vasomotion, and vasodilator capacity on MSI, we studied 12 patients with chronic CAD with coronary angiography and rest-mental stress-dipyridamole N-13 ammonia quantitative PET. Myocardial blood flow (MBF) and coronary flow reserve (CFR) was calculated using a 3compartment model. Among 261 regions (reg), 43 reg (16%) showed decreased MBF during mental stress (MS). Of these abnormal reg, only 13 (30%) showed abnormal CFR with dipyridamole (in reference to normals). In these abnormal reg, coronary stenosis severity was mild (<50%) in 16 reg, moderate (50-70%) in 10 reg, and severe (>70%) in 17 reg. These data indicate that reduction in MBF during MS may occur despite preserved vasodilator capacity with dipyridamole and lack of severe epicardial coronary disease, suggesting a primary role for vasomotor abnormalities,

Journal of Nuclear Cardiology Volume 6, Number 1, Part 2

Abstracts Monday morning, April 19, 1999

4.49

4.51

VITAMIN C IMPROVES THE CORONARY VASOD1LATOR RESERVE IN ASYMPTOMATIC SMOKERS Philipp A. Kaufmann, Tomaso Gnecchi-Ruscone and Paolo G. Camici MRC Cycletron Unit, Hammersmith Hospital, Imperial College School of Medicine, London (UK) Background Coronary endothelial function and vasomotion are impaired in smokers without coronary disease and this is thought to be due to increased oxidative stress. To test this hypothesis, we measured the coronary vasodilator reserve (CVR) in smokers and controls before and after administration of the antioxidant vitamin C (Vit C). Methods Myocardial blood flow (MBF, ml/min/g) at baseline (B) and during iv adenosine (Ado; 0.14 mg/kg/min) was measured in 8 healthy males (GR1) and 11 age-matched asymptomatic male smokers (GR2) using positron emission tomography and oxygen-15 labeled water. Thereafter, B- and Ado-MBF were repeated after 3 g of Vit C, infused iv over 10 minutes. CVR was calculated as Ado-/B-MBF after correcting B-MBF for the rate-pressure product, an index of cardiac work. Results Heart rate and mean arterial blood pressure were similar in both groups at rest and during Ado before and after Vit C. Before Vit C After Vit C B-MBF Ado-MBF CVR 1 B-MB Ado-MBF controls smokers

S 13

CVR 2

1.3+.2 1.3+.1

3.9_+.8 3.1_+.6 1.4-+.3 4.2_+.5 3.1_+1.1 3.5-+.3 2.7_+.3 1.3_+.2 4.2_+.5* 3.1_+.5" (* p<0.05 vs baseline) Conclusion The finding that Vit C improves CVR in smokers provides evidence that increased oxidative stress contributes to coronary endothelial dysfunction in individuals with this habit.

4.50 QUANTITATIVE EVALUATION OF MYOCARDIAL B L O O D F L O W (MBF) AND C O R O N A R Y R E S E R V E (CR) BY P E T IN E A R L Y H E A R T TRANSPLANT (tiT). P.Zanco, U.Livi, A.Desideri, S.Cargnel, V.Tursi, G.Mobilia, E.Milan, G. Thiene. PET Center, Castelfranco V., Italy. Quantitative NH3-PET was proposed to detect allograft coronary artery disease after I-IT, but the studies are limited in number and the variations of MBF and CR early after HT are unclear. To this aim 16 patients (15m, aged 54_+10 y) without clinical or histologic evidence of rejection were enrolled. They were submitted (30-60 d. after HT) to NH3 PET at rest and after dipyridamole infusion (0.56 rag/k). MBF was calculated using a Patlak modified method. At qualitative analysis of PET images, no patient showed segmental uptake defects both in the basal and in the dipyridamole images. At the quantitative analysis the mean basal MBF was equal to 0.85+0.21 (range 0.44-1.38). The CR appeared reduced with respect to the normal subjects (mean 1.99_+.0.71), but with a large variability in the values among the patients (range 0.9-3.2).The changes in CR appeared not correlated to the cause of death of the donors,to their age and sex, to the inotropic therapy,to the time of ischemia and to the method of eardioplegic protection of the tranplanted heart.In conclusion our study showed a reduction in CR early after HT, with a large variability among the patients, in absence of clinical and histologic signs of rejection. Follow-up studies could reveal the correlation between lower values and late rejection.

REPRODUCIBILITY OF MYOCARDIAL BLOOD FLOW AND FLOW RESERVE MEASUREMENT WITH POSITRON EMISSION TOMOGRAPHY Philipp A. Kaufmann, Tomaso Guecchi-Ruscone and Paolo G. Camici MRC Cyclotron Unit, Hammersmith Hospital, Imperial College School of Medicine, London (UK) Background Positron emission tomography (PET) allows absolute quantification of myocardial blood flow (MBF) at baseline (B) and during pharmacologically induced hyperemia (H) for the non invasive measurement of the coronary vasodilator reserve (CVR=H/B-MBF). We aimed to test the short term reproducibility of PET to assess CVR. Methods Using PET with oxygen-15 labeled water in 21 healthy male volunteers (age 48_+8 years), 4 consecutive MBF (ml/min/g) scans were carded out within 60 minutes. Study 1:B1 and HI (iv adenosine 0.14 mg/kg/min). Study 2:B2 (10 minutes after stopping adenosine) and H2. The repeatabilty coefficient (rep.coeff.) was calculated according to Bland and Altman as 2xSD of the mean difference between 2 paired values and given as absolute value as well as percentage of the mean between the two measurements. B-MBF was corrected (corr) for rate -pressure product (RPP) as: MBFcorr=-MBF/RPPx 104. Results The reproducibility of RPP was better at B (rep. coeff 17%) than during H (rep. coeff. 30%). Values in the table are mean+SD. MBF-B MBF-Bcorr MBF-H CVR CVRcorr Study 1 .90+.14 1.25+.22 3.50+.76 3.96+.75 Study 2 .99+.15 1.36+,27 3.86_+,48 3.97+.71 rep.ceeff.17 (17%) .29 (23%) .94 (25%) ,25 (32%)

2.90+.70 2.95+.72 1.05 (36%)

Conclusion Although PET-MBF measurements are reproducible, the rep. coeff, of CVR is around 1/3 of the mean value. This variability seems to be due mainly to a variable hemodynamic response to adenosine rather than to methodological issues as indicated by the larger rep. coeff, of RPP during H.

4.52 ABSOLUTE QUANTIFICATION OF CARDIAC BLOOD FLOW MEASUREMENTS IN PIGS WITH THE ECAT EXACT 3D AND H:150: PRELIMINARY RESULTS K.P. Sch~ifers, O. Rimoldi, M.P. Law, P.M. Bloomfield, C.G. Rhodes, O. Schober, P.G. Camici MRC Cyclotron Unit, RPMS, Hammersmith Hospital, London, UK Absolute quantification of myocardial blood flow with H2'50 has been widely established on 2D scanners and validated in animal experiments. With 3D scanners similar problems have to be solved before the measured tomographic data becomes an almost linear relationship with the actual activity distribution. Especially in the chest effects like scatter and radiation from outside the field of view due to the lack of shielding can harm sensitively the quality of the results. This study is done as a first step to validate the whole process of getting absolute quantitative results with the scanner ECAT EXACT 3D. Pigs are scanned using H~50 (90 MBq). After a baseline scan the flow in the LCx is reduced (= 30 % of baseline flow) by partially inflating an intraluminal balloon. Two [~50]water scans are performed with a concurrent injection of microspheres (57Co and 46Sc) under rest and stress (dipyridamol, 0.56 mg/kg) conditions. Post-mortem the heart is cut into 52 segments and analysed with autoradiographic methods. The scan data, acquired in list mode, are sorted into dynamic frames and reconstructed applying scatter corrections. Images are generated using factor analysis. Sixteen regions are drawn according to the autoradiographic segments and time activity curves are fitted using a well-established flow model. The comparison of the absolute flow values against microspheres measurements shows an agreement of +-0.28 ml/min/ml in a range from 1.5 to 2.5 ml/min/ml (Bland-Airman). The results promise the possibility to analyse humans in the very next future although more experiments have to be done to validate the correctness of the measured data.

M O N D A Y A M A P R I L 19

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Abstracts Monday morning, April 19, 1999

Journal of Nuclear Cardiology January/Febrnary 1999, Part 2

4.53

4.55

Effect of Nitroglycerin on Myocardial Perfnsion in Patients with Coronary Artery Disease and Normals M.Bettcher,M.M. Madsen, T.Toftegaard Nielsen, Dep.of Cardiology B, and The PET Center, Aarhus University Hospital, Denmark

ROLE OF NH3/FDG-PET IN THE SCREENING OF DILATATIVE CARDIOMYOPATHY (DC). P.Zanco, G.M.Boffa, P.Dalla Valentina, R.Chioin, G.Thiene. PET Center Castelfranco V., Italy. The accurate etiologic diagnosis in DC, relevant in the therapeutic decision making, may be obtained only using coronary angiography (CA).To evaluate the possibility that PET could be an useful tool in differentiating idiopathic DC (IdDC) from ischernic DC (IsDC), 20 pts (aged 57±10 yrs, 15 M, 5 F) affected by left ventricle dilation were enrolled (left ventricle telediastolic volume _> 120 cc/m2, EF _< 40%) and divided in two groups of 10 pts each according to CA: A) no coronary stenoses or secondary lesions at biopsy (IdDC), B) at least 1 critical coronary stenosis (IsDC). The haemodynarnic features of the pts in two groups were similar. Besides CA, all the patients were submitted to F18-FDG PET (glucose load technique) and N13NH3 PET (at rest), calculating, by ROIs, a score based on the extension and the severity of the uptake defects. The results are: IdDC IsDC p score range 0-1 4-19 NH3 PET mean±SD 0.1±0.3 10.6±5.1 <0.0001 score range 0-12" 2-17 FDG PET mean±SD 2.4:L4.4 9.9±4.1 <0.0001 * the 3 pts with score >1 presented left bundle branch block (LBBB) In conclusion, in our study: 1) both NH3 PET and FDG PET allow a clear distinction of IdDC (score < 1) from IsDC (score > 2); 2)patients affected by LBBB could present defects in FDG uptake also in IdDC; 3) if our data is eonfn-med in a larger group of patients, the use of PET instead of CA in DC management could allow the saving of about $1500 per patient.

Despite being the perhaps most effective and widely utilized drug for angina peetoris, little is known about the mechanism of action of nitroglycerin (NTG). NTG exerts its effect on both peripheral veins and arteries and on the coronary vessels. The effect differs between different vessel sizes. These complex interactions makes a prediction of the NTG effect on the myocardial microcirculation difficult. Therefor myocardial blood flow (MBF) was quantified under baseline conditions with N- 13 Ammonia PET at rest (MBFrest) and after oral Nitroglycerin 400 ~tg (MBF-NTG) in 14 patients with angiografically proven single or double vessel coronary artery disease (63+7 years, 18 males) and in 20 healthy young volunteers (24+_5 years,10 males). MBF was quantified in areas supplied by stenosed (>70% stenosis) and non-stenosed (<30% stenosis). Coronary vascular resistance (CVR) was calculated as MBF/mean arterial blood pressure. *)p<0.05 I MBF-rest CVR-rest MBF-NTG CVR-NTG Controls (20) 0.79+_0.28 1i0_+25 0.87+_0.25 98+_19 Stenosed (16) 0.53+_0.17 170+35 0.69+_0.17" 129+_30" Non-stenosed(14) 0.67+_0.22 135+_27 0.76+_0.20 119+_21 asion, NT( ; only signifi ters' myocardial i lslon m areas supplied by stenosed arteries. Therefor, NTG ell her does not have a net effect on the microcirculation or it is counteracted by autoregulatory mechanisms. In areas supplied by stenosed arteries NTG seems to reduce resistance and thereby increase flow.

4.54 PREDICTION OF LEFT VENTRICULAR FUNCTIONAL RECOVERY AFTER REVASCULARIZAT1ON BY RESTRED 2°~TISPECT AND ~3N, ~SFDGPET. M Hernandez-Pampaloni,V Petal, I Vilacosta, E Merofio,JL Carreras. San Carlos Univ. Hospital, Madrid,Spain. Detection of viability is an important issue for the prediction of left ventricle functional recovery after revascularization. The aim of this study was to assess the value-that 2°1TI, ~3N and lSFDG have to predict functtona[ recovery in patients with severe left ventricular dysfunction. 34 patients (mean age 62±07 years, LVEF31±11% with 2.1 stenosed vessels) underwent echocardiography before and 5 weeks after revasculadzation to assess improvement of regional function. 2mTI SPECT, PET and angiography were performed in patientspdor to revasculadza~n. We used a 11-segment LV and semi-quantitative analysis of all test. Improved segmental LV thickening in 226 severe hypokinetic segments at followup vs baseline rest echo was used as gold standard for viability.After revasculadzation 111 segments (49%) showed improvement. m~TI R/Red FDG uptake PET Mis. Sensitivity 83 79 55 Specificity 39 60 91 PPV 53 63 75 NPV 69 74 64 (Values in %) The results indicate that 2°1TI R/Red SPECT and PET have similar sensitivity to predict functional recovery but PET shows a higher specificity,especially Mismatch cdteria than

20~Ti"

4.56 UTILITY OF 18F-FDG PET IN THE DIAGNOSIS OF CARDIAC SARCOIDOSIS W.Okumura, T.Toyama, A.Miyajima, T.Hatori,H.Sato, T.Iwasaki, R.Nagai, T.Suzuki, T.Inoue, K.Endo Gunma University School of Medicine,Maebashi,Japan Cardiac sareoidosis, the main cause of death among patients with sarcoidosis, frequently becomes clinically apparent when the disease is far advanced. To evaluate the usefulness of the 181=fluorodeoxyglucose (FDG) positron emission tomography (PET) in detecting cardiac sarcoidosis, 18F-FDG PET was performed in 16 patients with sarcoidosis (13 female, 63 +__12 years.), compared with scintigraphic findings of 99mTc-MIBI, and 67Ga. Ten of 16 patients were diagnosed as cadiac sarcoidosis on clinical grounds with tissue confirmation such as positive endomyocardial biopsy, severe ventricular arrhythmia, more than second degree atrioventricular block, and echocardiographically proven ventricular dysfunction. Among these clinically diagnosed patients as cardiac sarcoidosis, abnormal myocardial uptake of FDG were observed in all confirming high diagnostic sensitivity (100%) compared with of MIBI SPECT and 67Ga scintigraphy (80% and 50%) . Although abnormal FDG accumulation were observed in the region with decreased uptake of MIBI in many cases, localization of regional abnormality of each tracer was frequently independent.This discrepancy may reflect inflammatory and degenerative process of myocardium in cardiac sarcoidosis. FDG PET is thought to be a useful nonivasive method in detecting cardiac involvement of sarcoidosis and may provide a useful information on the activity of the disease.

Journal of Nuclear Cardiology Volume 6, Number I, Part 2

4.57 CHANGES IN MYOCARDIAL ENERGY SUBSTRATE UTILIZATION AND FUNCTION IN PATIENTS WITH CD36 DEFICIENCY. Y. Ishida, K. Komamura, K. Fukuchi, M. Toba, K. Fukushima, K. Miyatake. National Cardiovascular Center, Osaka, Japan. We experienced 1t patients whose platelets and monocytes did not express any cell surface CD36, a membrane glycoprotein that acts as a receptor for long-chain fatty acids (designated as a type I CD36 deficiency). All these patients showed absence of myocardial 1-123 BMIPP (a long-chain fatty acid tracer) uptake. We studied changes in left ventricular (LV) fimction with cardiac catheterization and myocardial glucose utilization rate (MGU) with F-18 FDG dynamic PET in the fasting state in these patients. The patients were nondiabetic and consisted of 4 with coronary artery disease (CAD), 2 with dilated cardiomyopathy (DCM), 3 with arrhythmias, 1 with hypertrophic cardiomyopathy and 1 with nonspecific ECG changes. The patients who did not have CAD or DCM showed normal LV ejection fraction (61_+8 %) and wall motion. Coronary revascularization for the 2 CAD patients and 13-blockertreatment for the 2 DCM patients improved LV function, but did not induce myocardial 1-123 BMIPP uptake. MGU values were higher in these 11 patients than in 12 age-matched normal subjects (5.1_+1.9 vs. 1.8_+0.6 mg/mirdl00 g, p<0.001). However, MGU was correlated with blood free fatty acid (FFA) concentration in these patients (r= 0.576, p<0.0l) as well as in normal subjects. Thus, in patients with a type I CD36 deficiency, the chief myocardial energy substrate switches from fatty acids to glucose, but the inverse correlation between MGU and FFA suggests that the utilization of fatty acids other than long-chain fatty acids may be preserved and contribute to the maintenance of myocardial energy metabolism and function.

4.58 MYOCARDIAL GLUCOSE UTILIZATION IN CARDIAC TRANSPLANT PATIENTS. Roxanne A. Rodney, Donna Mancini, Ru-Ling Chou. Columbia University, New York, N.Y., USA Despite the altered hemodynamics exhibited by cardiac transplant patients, little is known about the metabolic function of the cardiac allograft. To evaluate the rate of exogenous glucose utilization by the cardiac allograft, 15 cardiac transplant patients (11 men, 4 women) underwent F-18 fluorodeoxyglucose positron emission tomography after oral glucose loading. Patients were 21+ 17 months post-transplant. Global and segmental myocardial glucose utilization rates were quantitatively measured using Patlak graphical analysis. Global mean myocardial glucose utilization (MGU) = 0.39 +0.19 mumol/g/min. In a database group of normal volunteers mean MGU = 0.55 + 0.04. Regional heterogenity in MGU was preserved in the cardiac transplant patients, who demonstrated significantly greater uptake in the posterior and lateral wall MGU = 0.43 +0.23, compared with the anterior and septal wall MGU = 0.37 + 0.18 (p= 0.004). Thus, this data indicates that global myocardial glucose utilization in cardiac transplant patients is not significantly different from normals and that regional heterogenity in glucose utilization is preserved.

Abstracts Monday morning, April 19, 1999

S 15

4.59 E F F E C T O F N I C O R A N D I L ON S Y N D R O M E X - E V A L U A T E D BY 1 8 F D G - P E T O.Satake, K.Masuyama, N.Takekoshi, S.Matsui, H.Tsugawa, S.Kanemitsu, S.Okubo, T.Asaji, M.Kitayama , T.Yamagata, S.Miura, S.Fujino, S.Katsuda, Y.Ishikawa Dept. of Cardiology, Kanazawa Medical University, Ishikawa, Japan Objective: In patients with Syndrome X ( SNX ) who

clinically presented with angina-like symptoms, but stenosis was not detected by coronary angiography ( CAG ), changes in metabolism were compared using I~FDG-PET before and after nicorandil administration. Subjects and Methods: Twelve patients ( 3 males and 9 females, mean age 54.9 years ) with SNX were studied. Administration of a K channel opener ( nicorandil, 20mg/day ) was started after the end of CAG, left ventricular angiography ( LVG ) and 18FDG-PET, and images of CAG, LVG and ~8FDG-PET taken again 3 months later during administration were compared with those before administration. Results: Of 12 patients diagnosed with SNX, 1. Uptake was observed on aSFDG, allowing a diagnosis of ischemic heart before nicorandil administration in all patients. 2. Three months after nicorandil administration, uptake had disappeared on tSFDG, indicating improvement of ischemia in 10 / 12 patients ( 83% ).Conclusion: ~8FDG-PET demonstrated the usefulness of a K channel opener for myocardial ischemia in SNX

4.60

INSULIN RESISTANCE IN PATIENTS WITH IDIOPATHIC DILATED CARDIOMYOPATHY ASSESSED BY FDG PET. IMPLICATIONS FOR METABOLIC INTERVENTION? HJ Siebelink, AFM van den Heuvel, PK Blanksma, DJ van Veldhuisen, W Vaalburg, HJGM Crijns. University Hospital Groningen, The Netherlands Insulin resistance (IR) may reduce glucose uptake in dysfunctional myocardium in idiopathic dilated cardiomyopathy (IDC). Therefore myocardial glucose uptake might be influenced by metabolic imaging conditions. Methods: FDG PET uptake was studied in 12 IDC-patients during hyperinsulinemic euglycemic clamp (clamp) and compared to 17 IDC-patients who underwent FDG imaging with oral glucose loading (load). Results: Age and LVEF (27+_10% vs 34+_15%) were not different in both groups (load and clamp resp.). In load a positive correlation was observed between FDG-uptake and LVEF (r= 0.37,p=0.15), while clamp showed a negative correlation (r= -0.38,p=0.22). Regression lines of load (FDG=0.82 LVEF+30.5) and clamp (FDG= -0.50 LVEF+76) were significantly different by ANOVA (p=0.03). Conclusion: In IDC FDG-uptake is influenced by metabolic imaging conditions and difference between load and clamp can be explained by IR. With clamp IR was circumvened and preserved FDG uptake was demonstrated. This implicates a rational basis for metabolic intervention in IDC.

M O N D A Y A M A P R I L 19

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Abstracts Monday morning, April 19, 1999

4.61 CARDIAC AND RESPIRATORY GATING OF LIST-MODE DATA ON A HIGH SENSITIVITY PET SCANNER, THE ECAT EXACT3D. L. Livieratos, P Bloomfield, D Bailey, O Rimoldi,C Rhodes,T Jones, P Camici. MRC Cyclotron Unit, Hammersmith Hospital, London,UK The ECAT EXACT3D is a high-sensitivity, 3D-only PET scanner with 48 detector rings covering an axial FOV of 23.4cm and a wide patient port to allow chest imaging. Acquisition of list-mode data is enabled by a 32Mbyte RAM buffer memory and a 34Gbyte RAID hard-disk in the acquisition hardware (ACS II) which can achieve transfer rates of >]4Mbytes/sec (>3.5 MEvents/sec). Timing events are inserted into the flow of data at every millisecond achieving high timing resolution. Additional information from physiological signals can be encoded into 4 bits allocated for this purpose at every timing event allowing up to 16 gating states to be encoded at each time. We use a device that monitors respiration through changes of the inductance of a flexible wire incorporated into an elasticised belt around the patient's chest. The respiration signal is encoded into gating states 0 to 15. The 16th gating state is defined by the Rwave trigger from a 3-lead ECG monitor. The raw list-mode data are sorted post-acquisition into gated sinograms corresponding to different cardiac and/or respiratory phases. Adequate counting statistics due to the high sensitivity of the EXACT3D allow data sorting into a number of frames to provide dynamic gated images. Retrospective data sorting enables increased flexibility in frame and gate definition tailored to the clinical application or the specific data set: Dynamic images from the end-systolic, end-diastolic and intermediate phases of the cardiac cycle have been produced from H2150 cardiac scans and images of end-expiration, end-inspiration and intermediate respiratory states from 18FDG and C150 scans. With this methodology we can improve the effective spatial resolution of t h e dynamic data for accurate extraction of pharmacokinetic parameters.

4.62 MYOCARIDIAL18-1:1gl6UPTAKEIS RELATEDTO 111ETRIGL¥CERIDE CONTENTOF THE INTERMEDIATEDENSITYUPOPROTEINS. A Steinmetz,B Cronin,A Wierzbicld*,MN Maisey. Clinical PET Cenb'eand *ChemicalPathology,UnitedMedicaland Dental Schoolsof Guy'sand St Thomas'sHospitals,London,UK. IMIt~lll¢llOll: 18-FDG PET scansof the chestare frequenWdegradedin qualityby unexpectedlyincreasedmyocardialuptake. "Hot"myocardiumis undesirablein oncologloPET imagingas it may hide somefindingsin the lower chestor may create imagingartifactssimulatingnonexistentlesions. This prospectivestudywas aimedto revealpossiblerelationsbetween plasmalipidlevelsand myocardialFDG uptake. MMIINS: Bloodsamples were obtainedfrom46 patientsafterovernightfasting. Followingthisthe patientswere injectedwith 18-FDGto performthe whole-bodyPET whichthey were referredfor. The bloodsampleswere assayedfor total plasmacholesterol and triglycerides,cholesterolend triglyceridecontentof the lipoproteins, a.po-lipeprotems,free fattyacids,Lp(a), bloodsugarand insulin.The intensity of the myocardialFDG uptakeon the PET scanwas estimatedby visual scoringwithoutquantificationas the whole-bodyscanswere performedwith no attenuationcorrection.The patientswere assignedto two groupsaccording to theirmyocardialuptake:groupA with low and groupB with high uptake in the myocardium.The correlationsbetweenthe myocardialuptake and each of the above mentionedassayswere examinedby Student'st-test. IleSllltS: GroupsA and B differedsignificantlyin the triglyceddecontentof the intermediatedensitylipoproteins(TG-IDL):0.t23 + 0.04 mmol/Lin group A versus0.085:1:0.04mmol/Lin groupB, p = 0.007. Noneof the other parametersstudiedwas signiflcan'dydifferentin the two studygroups. C611¢111si011:MyocardialFDG uptakeis relatedto TG-IDL, higherTG-IDL is associatedwith reducedFDG uptakein the myocardiumand viceversa. An adequatedietarypreparationand a schedulingaimedat increasingthe TGIDL levelsat the timeof an oncologicFDG studyare expectedto resultin suppressionof myocardialFDG u..ptakewhichin turnshouldimprovescan quality,increaselesiondetectabilityand reduceartifactsin FDG-PETscans of the chest.

Journal of Nuclear Cardiology January/February 1999, Part 2

8.1 COMPARISON OF REST AND POST STRESS LEFT VENTRICULAR FUNCTION BY GATED SPECT T. Sias, D. Watson, (3. Belier. University of Virginia Health Sciences Center, Charlottesville, Virginia, USA The purpose of this study was to compare gated SPECT quantification values of left ventricular ftmction (LVEF) obtained at rest and post stress. Quantification of resting (REF) and post stress LVEF (SEF) was obtained in 83 patients using the UVA method of quantification. The Cedars-Sinai technique was also used to calculate LVEF. Good correlation was observed between the two methods. On B l a n d - A i m atmlysis, which was used to detect differences in REF and SEF, the standard deviation (SD) for UVA SEF and REF paired measurements was 5.4%. For CS, the standard deviation was 6.0%. By the UVA method, two patients had >2SD change between SEF and REF. By CS method, there were 3 patients with >2 SD change. The statistically expected number of samples lying more than 2SD from the mean is 1.9. Thus all of the observed changes comparing SEF and REF are explained as statistical variance, and no additional variance remains to be attributed to true stunning. We can estimate that the incidence of true stunning in this randomly sampled patient population, which is <4% at the p=0.05 confidence level. In a randomly sampled patient population, the incidence of post stress myocardial samning is small. Differences in post stress LVEF and rest LVEF are explained by measurement error. We have previously shown measurement error to be less on high-dose studies, which are typically post-stress.

8.2 ACCURACY OF GATED-SPECT IMAGING IN DIAGNOSING INDIVIDUAL CORONARY ARTERY STENOSIS: A COMPARISON BETWEEN UNGATED AND GATED IMAGES. Felix Keng, Raj Chandwaney, John Mahmarian, Mario Verani. Baylor College of Medicine, Houston, Texas, USA. Gated-SPECT of myocardial perfusion images is now widely used. However, no information is available on whether gated end-systolic (G-ES) or gated end-diastolic (G-ED) images would improve the accuracy of SPECT for detecting individually stenosed arteries, as compared to ungated (UG) images. Accordingly, we studied 63 patients Cots) with GSPECT and coronary angiography. Fifty-three pts had _>50% coronary stenosis on angiography. Overall sensitivity for coronary artery disease (CAD) detection was 91% with UG, 91% with G-ES and 96% with G-ED. Sensitivity for detecting individual artery stenosis was higher (p<0.01) with G-ES (71%) and G-ED (79%) than by UG (58%), but specificity fell from 69% with UG to 60% with G-ES and 44% with G-ED (p<0.01). Thus, perfusion evaluation on the basis of G-SPECT images affords similar overall sensitMty as UG images for CAD detection. An increased sensitMty of G-SPECT for detecting individually stenosed arteries is offset by lower specificity and hence does not improve the test's accuracy.

Journal of Nuclear Cardiology Volume 6, Number 1, Part 2

Abstracts Monday morning, April 19, 1999

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8.5

8.3 QUANTIFICATION OF LEFT VENTRICULAR VOLUMES AND EJECTION FRACTION FROM GATED 99mTcMIBI SPECT BY TWO DIFFERENT METHODS: COMPARISON WITH CARDIAC CATHETERIZATION

A. Fikrle, D. LOscher, M. Fleisch, J.A. Kinser, S. Lourens Inselspital, University of Beme, CH-3010 Berne, Switzerland The aim of this study was to compare two different methods for the determination of left ventricutar volumes and ejection fraction by gated 99mTc-MIN SPECT (GSPECT) and to correlate their results with ~nqiography (ANG). 57 cor~secutive patients (28 after MI) were examined according to a 2-day stress(S)/rest(R) protocol using a 3-head camera. Each patient underwent cardiac catheterization within 2 weeks of the GSPECT. Two independent observers determined end-diastolic volume(EDV) end-systolic volume (ESV) and ejection fraction (EF) by two different mettiods: 1) semiautomatic using "perfusion motion map (PMM)" according to T.L. Faber and 2) automatic using "quantitativegated SPECT (QGS)" according toG. Germano. Linear regression and w-test were used to compare GSPECT with angiographic parameters. The correlation coefficients were: EDV: S-PMM=0.47 S-QGS=0.54 R-PMM=0.49 R-QGS=0.59 ESV: S-PMM=0.74 S-QGS=0.80 R-PMM=0.78 R-QGS=0.81 EF: S-PMM=0.81 S-QGS=0.85 R-PMM=0.87 R-QGS=0.88 The mean values of EDV, ESV and EF in all GSPECT groups were significantly lower than in ANG. There was no significant difference between two observers for both PMM and QGS. In comparison with ANG, the worst correlation was found for EDV, while the correlation for ESV and EF wasgood. PMM and QGS systematically underestimate EDV, ESV and EF (PMM more than QGS). The greatest difference between ANG and GSPECT was found for EDV, most likely because of inclusion of larger outflow tract areas in ANG than in GSPECT; the difference for ESV and EF was smaller than for EDV. PMM and QGS are reproducible (QGS somewhat better) and provide clinically useful quantitative information regarding systolic function. Of all compared parameters, QGS was slightly better than PMM, most likely due to automatic processing.

FRAMES A CARDIAC CYCLE IN QUANTITATIVE GATED SPECT (QGS) FOR CLINICAL USE: 8 VERSUS 16 K Imai, Y Azuma, T Nakajima, S Yamazaki, K Iwano, N Hayafune, M Muto, T Shibata, Y Ogawa, J Suwa, H Horie. Saitama Cardiovascular Center, Saitama, JAPAN We studied whether number of frames a cardiac cycle affect the result ofQGS: QGS was recorded by 16 frames a cardiac cycle in 30 patients. Data were summed every 2 frames for 8 frames a cardiac cycle (frame 1+2, 3+4, ets.). Both 8 and 16 frames QGS were reconstructed respectively. Left ventricular end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) were obtained. Wall thickening (WT) was evaluated in 8 segment of left ventricle by 10 grade score (0:akinesis to 10:hyperkinesis). According to WT score (WTS) on 16 frames QGS (16WTS), 240 segments were divided into 2 groups, dysfunction area (DF, 16WTS <4, n=104) and normal area (NO, 16WTS>4, n=136). Result is shown as m e a n+- SE. 16 flames QGS 8 frames QGS p EDV (ml) 95.2--+6.2 93.2-+6.1 <0.001 ESV (nil) 40.3 - + 4 . 6 42.9+--4.7 <0.001 EF (%) 60.4-+2.3 56.7-+2.2 <0.001 WTS in DF 2.7-+0.1 2.6-+0.1 n.s. WTS in NO 6.4-+0.1 5.4-+0.1 <0.001 Difference of EDV, ESV and EF between 8 and 16 frames QGS are statistically significant. However difference of EF is only 3.8% Difference of WTS between 8 and 16 frames is not different in DF. Thus, 8 frames would be enough frame number a cardiac cycle on QGS for clinical use.

8.4

9.1

G A T E D S P E C T R E C O N S T R U C T I O N WITH Z O O M A N D DEPTH D E P E N D E N T FILTER I M P R O V E S A C C U R A C Y O F V O L U M E A N D LVEF IN S M A L L HEARTS.

SIGNIFICANCE OF RECRUITABLE COLLATERALS DURING PTCA EVALUATED BY 99mTC-SESTAMIBISPECT Niels P. Sand, Michael Rehling, Jens P. Bagger, Left Thuesen & Torsten T. Nielsen. Dept. of Nuclear Medicine and Cardiology, Aarhus University Hospital, Skejby Sygehus, Aarhus, Denmark.

R.G. Schwartz, L. Mixon, G. Germano, I. Chaudhary, K. Armstrong, M Mackin. Univ. of Rochester, Rochester, NY, USA. Erroneously high LVEFs reported in small hearts by gated SPECT (GS) may result from falsely low ESV and be obviated by using a 2.5 zoom (Z) and depth dependent adaptive filtering during reconstruction (R). To test this hypothesis, ESV and EF were analyzed by Cedars QGS TM in 30 patients with ESV <60 ml, using dual detector (SMV DST) GS and a) R with standard Butterworth (BW) 5/.30 without Z, b) R with BW 5L30 with Z, and c) R with Metz (M) 3.5 FWHM Order 8 adaptive filter with Z. Results were compared with a reference method MultidimTM (MD) previously validated with first pass RNA. Results: (LVEF %; volumes ml; mean -+ SD). LVEF i ESV EDV

BW

BW + Z

M +Z

MD

67+12

62+10

57+9

59+9

21+11

39+18

51+20

49+19

60+15 99+24 117+25 116+25 Differences compared to the MD reference method were highest for BW and lowest for M + Z for EF, ESV and EDV (p<<<0.001 for each, paired t-test). We conclude GS reconstruction zoom and resolution recovery filtering improve volume and EF calculations on small hearts.

We evaluated the impact of recruitable collaterals by 99mTcsestamibi SPECT during PTCA. Thirty patients with stable angina pectoris and proximal non-occluding LAD-stenoses scheduled for PTCA were included. Visualization of recntitable collaterals, registration of coronary wedge pressure and injection of 99mTcsestamibi were undertaken during occlusions lasting 90 seconds. ECG-changes were continously recorded. The defect severities were calculated as the mean PTCA-induced defect pixel count divided by the mean pixel counts in identical regions at rest. A significant correlation was found between the coronary wedge pressure and the scintigraphic PTCA/rest count ratio (R2 =0.34; p<0.001). This ratio was higher in patients with recruitable collaterals (p<0.05). -RST-elevation

+RST-elevation

5 2

22

5 2

4 19

7 0

9 14

PTCA/rest-ratio,SPECT"

> 70% _<70%

I

Coronarywedge pressure""

> 30 mmHg _<30 mmHg Recruitablecollaterals-Grade 2 or 3 Grade 0 or 1 * p
Perfusion imaging by mibi-SPECT during PTCA can discriminate patients with a sufficient collateral supply from those without.

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M O N D A Y A M A P R I L 19

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Journal of Nuclear Cardiology January/February 1999, Part 2

9.2

9.4

BLUNTED AUGMENTATION OF MYOCARDIAL PERFUSION AT EXERCISE ASSESSED BY QUAN'ITrATIVE TC-99M TETROFOSMIN SPECT IN CORONARY ARTERY DISEASE H. Sasao, T. Nakata, H. Kobayashi, K. Miyamoto, K. Tsuchihashi, K. Shimamoto. Sapporo Medical University, Sapporo, Japan.

STANDARDOR HIGH DIPYRIDAMOLEDOSE FOR THE EVALUATIONOF DEFECT SIZE AND SEVERITYBY TC-SgmSESTAMIBISPECT? E.Milan, A.Tena, P. Rossini, R.Giubbini. Nuclear Medicine Service, Civic Hospital of Bre~i~ltaly

We investigated the clinical efficacies of newly developed quantitative analysis of exercise-stress Tc-99m-labeled tetrofosmin SPECT in stable coronary artery disease (CAD). Exercise/rest tetrofosmin SPECT was performed in 63 patients. In addition to visual analysis and % peak-count calculation, an exercise-induced myocardial count was evaluated as the relative value (%IR) to that at rest by correcting with a physical delay and injected doses. Diagnostic efficacies of visual assessment were as follows; positive predictive value 86%, negative predictive value 68%, false positive 14%, and false negative 32%. Segments with abnormal visual score had significantly lower % IR than that with normal perfusion score; 34_+33% in abnormal segments with fill-in, 49!-_39% in those without fill-in, and 101_+37 in normal segments. Visually false negative segments had a significantly lower %IR (40_+37%) than control areas in CAD patients (70_+34%) and normal areas in control subjects (101_+37%). When % IR less than 40% was define as abnormal, 51% of coronary lesions showing visually false negative were precisely identified with a good negative predictive value of 73%. Thus, blunted augmentation of myocardial perfusion at exercise in CAD patients can be assessed by exercise-stress tetrofosmin SPECT and the identification might contribute to improved detection of myocardial ischemia.

Dipyridamole is a reliable, widely accepted, altemaU~ to exercise slmes testing for myocar~al per[usionimaging. Dipyddamolemechanism of acSonis indirect and, unlike Adenosine, a ,subopt~ coronary vasodlation may be hypothesised. Ptapose of this study was the evaluation of the potenlial benefits of a high Dipyddamoledose (HDD) for m ~ a J MIBI SPECT. 140 pts, with predo~ myocar~al infarctionand recentcatheterizaUon,~ t MIBI SPECT alter 0.84 mg/Kg/5min Dipyddamole dose (study group-SG). The controF group (CG) consisted of 89 pts evaluated by standard (0.56 mg/Kg/4min) Dipyridamoledose (SDD). Extension{% of left ventricle surface) and sevedty (arbitran/ units) of revedble defects were c~ant~ed in comparisonto gender matchedpotar maps, Both gn:mpswere dvided into pts who had (SGI & CG1) or had not (SG'2 & CG2) undergone to previous revascularizatJon procedures and were analyzed for meter of diseased vessels. Results: no major side effectswere observedalter HDD. Signifk~ant diffemrees both in severity and extension of reversibledefects were fou~ between SG2 and C.G2 (1656+1066 vs 1127+804; p<0.02); (13±9 vs 9±7; p<0.005). SignJFcantdifferencein sevedtywas found between SG2-1V & CG2-1V (1791:~:999vs 1162~:816; p<0.01) as well as between SG2-2V & CG2-2V (1419+1092 vs 922±797; p<0.05), but not between SG2-3V & CG23V. Reversibledefect extension was significantlydifferentbetween SG2-2V & CG2-2V(11+8 vs 7±8; p<0.05) and between SG2-3V& CG2-3V (15+11 vs 9+6; p<0.05) but not between SG2-1V & CG2-1V. SG1 & CG1 showed no significant differences in both reversible defect extendon and severity. Conclusions: SDD may be not sufficient to obtain maximal vasodilation in many pts and DHD seemsto increaseMIBI SPECTsens'~vity.

9.5

9.3 ROLE OF STRESS T H A L L I U M SPECT IN DETECTION OF SILENT MYOCARDIAL ISCHEMIA IN HYPERTENSIVE PATIENTS W I T H LEFT VENTRICULAR HYPERTROPHY(LVH) Khaled EI-Sabban,MD *, Ayman Kaddah,MD**, Hassan EI-Tokhy,MD **, Mohamed EI-Gabaly,MD***, Aza Katta,MSc***, and Add Emam ***MD

*NuclearCardiologyUnitCairoUniversity,**CardiologyDepartme.nt,Cairo UniVersity,***Caz'd!ologyDepartmentofNationalHeartInstitat¢. Backqround;,~Apidemological evidence suggests that hypertensive patients with LVH are at risk of all manifestations of CAD. Recent interest focused on symptom-freehypertensivepatients with LVH, since silent myocardial ischemia (SM[)perse, comprises an increased risk for cardiovascular moridity and mortality. A i m o f T h e S t u d y " To assess the incidence of silent myocardial ischemia in hypertensivepatients with LVH Patients a n d Methods: Seventy five patients with systemic hypertension had been subdivided into 2 main subgroups :Group I (hypertensive with LVH 52/75) and group II (hypertensivewithout LVH 23/75). All patients were subjected to: Clinical assessment, Non-invasive assessment (resting ECG, ambulatory Holter, Exercise thallium), and invasive assessment (Coronary angiography). Results: Group I revealed two main subgroups: one subgroup with no evidence of myocardial isehemia by either non-invasiveor invasive tests (11/52) (Group IA), and second group (IB)with positive non-invasive tests for myocardial ischemia (41/52). However, 6/41 cases showed normal coronaries (liB1)and 35/41 showed CAD (IB2). On the other hand, group II revealed negative both non-invasive and. invasivetests for ischemia. Conclusion:

Positive stress thallium test in hypertensive patients with LVH is an indication of myocardial ischemia even with normal coronary angiography. Patients of group 1331explains ECG findings of LVH with strain.

EFFECT OF PATIENT OBESITY ON THE ACCURACY OF QUANTITATIVE SPECT TL201 M Y O C A R D I A L P E R F U S I O N I M A G I N G C. L. Hansen, R. Sangrigoli, E. Nkadi, M. Kramer. Temple University Hospital, Philadelphia, P A Although it has long be appreciated that patient body habitus can reduce the accuracy of S P E C T T1-201 myocardial perfusion imaging, the effect of patient obesity is not known. To evaluate this, we identified 607 patients (pts) undergoing exercise perfusion imaging who were without a history of documented MI, pathologic Q waves, prior CABG, L B B B or nonischemic cardiomyopathy and who had either less than 5% probability of coronary artery disease or underwent cardiac catheterization within 60 days of stress testing. Pts with < 50 % stenosis were classified as normal. Twenty males and 20 females were taken from the normals and used only to create gender based normal databases. Obesity was defined as a body mass index (weight/height 2) > 30. Images were analyzed quantitatively and a defect score was generated. Accuracy was compared using the area under the Receiver Operating Characteristic (ROC) curve. Obese pts had lower accuracy (ROC area 0.86+0.03 vs. 0.92+0.02; p < 0.05) despite similar ratepressure product (22,800+5000 vs 22,000+5500; p = NS), peak heart rate (131+19 vs 133+20; p = NS) and severity of C A D (#vessels 2.0+0.8 vs 2.0_+0.8; p = NS). We conclude that patient obesity significantly reduces the accuracy of SPECT T1-201 myocardial perfusion imaging.

Journal of Nuclear Cardiology Volume 6, Number l, Part 2

9.6

Abstracts Monday afternoon,April 19, 1999

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13.2

TRANSIENT LV ISCHEMIC DILATION FOR THE DIAGNOSIS OF MULTIVESSEUEXTENSIVECAD WITH EXERCISETL-201 SPECT. D. Daou, N. Delahaye, R. Lebtahi, C. Poker, M. Faraggi, L. Sarda, D. Le Guludec. Bichat Hospital, Paris, France. Exercise (Ex) TI-201 LV transient ischemic dilation (LVTID) is a diagnostic indicator of extensive and/or multivessel CAD. Recently developped softwares allow its quantification. We studied the clinical additive value of its quantification with Multidim software for the discrimination between limited and extensive/multivessel CAD. Were studied 110 pts having an Ex TI-201 SPECT and 4 hour reinjection SPECT study and a coronary angiogram within a 3 months period. Pts were classified as having no CAD (n= 12), limited CAD (GI, n=20; 1V RC or Cx or nonproximal LAD) and extensive/multivessel CAD (GII, n=78; proximal LAD, 2V and 3V). Mean LVTID ratio in pts with no CAD was -3+tl providing a normal threshold of < 20%. This value was used to determine the presence of abnormally increased LVTID ratio: 25•78 pts (32%)in GII and 1/20 pts (5%) in GI (p<0.01). 28178 (36%) pts in GII and 1/20 (5%) pts in GI (p<0.01) presented a perfusion abnormality in >1 vascular territory. Combining these 2 criteria provides a detection rate of 39/78 (50%) pts in GII vs 2•20 (10%) pts in GI (p<0.01). Thus, Multidim quantification of LVTID provides additional information beyond that provided by perfusion abnormality alone for the discrimination of limited from multiple/extensive CAD.

DIAGNOSIS OF ANGIOTENSIN II MEDIATED TISSUE INJURY IN MI MODEL BY SELECTIVELY SEQUESTRATED ~l'c CONJUGATES. Raghoottama S. Pandurangi, Wang, T.N and Robert R. Kuntz, University of Missouri, Columbia, USA. Local de Novo generation of Angiotensin II (A II) has been implicated in fibrogenesis, deposition of extracellular matrix (ECM) and the subsequent remodeling of the heart following myocardial infarction (MI). Overexpression of A(II) receptor b y myofibroblasts (myoFbs), nonresident of normal myocardium at the interface between infarcted and viable islands of myocardium provides essential biological target for radioimaging agents (e.g. 9~r~Tc) to map out the nonviable portion of myocardium. We have prospectively evaluated ~r"Tc conjugated to A (11) receptor antagonist 1 for monitoring the proliferation of myoFbs (marker of All receptors) which determines the progression of tissue -.~-N-~ o injury. Our preliminary .... ~ ( ~ . . ~ investigations have , revealed a selective i~7 ° sequestration of ~ T c .~ "~ activity by fibrotic °tissues in a model of MI, created by coronary artery ligation. Sections of hearts with fibrotic lesion show 10-15 times more ~mTc activity compared to the normal heart sections. These results may be important for noninvasive visualization of nonviable segments with a positive hot signal and may be helpful for the overall assessment of myocardial viability.

Monday PM, April 19, 1999

13.3

Sessions 13, 14, and 15

SIMULTANEOUS HIGH RESOLUTION F18(FDG) /Tc99m(MIBI) MYOCARDIAL IMAGING USING A NEW DUAL ISOTOPE PET/SPECT PROTOCOL. J.Baron,L.Daley, G.Zubal, J.Seibyl, F.Wackers, B.Zaret. Tel Aviv Medical Center, Israel.

13.1 COMPARISON OF THE LANGENDORFF VS THE WORKING RAT HEART PERFUSION MODELS FOR THE ASSESSMENT OF FDG UPTAKE IN RESPONSE TO INSULIN. N. Nguyen, M. Schwaiger. Technische Universit&t M~nchen, Germany The purpose of this study was to compare the glucose metabolic rate (MR) in the 2 perfusion models with respect to the uptake of FDG and D-[2-H-3]glucose in response to insulin. Five hearts underwent retrograde perfusion according to Langendorff, while 3 hearts were perfused with a moderate work load. FDG uptake was monitored using a pair of BGO detectors. H-3glucose utilization was assessed by the appearance of H-3water in the effluent using columns containing converted AG-lX8 resin. Calculated MR expressed as Bmol/g tissue/min are presented Langendorff H-3 glucose FDG Baseline 0.11+0.02 0.20+0.04 Insulin 1.54+0.05 0.96+0.09 Working Model Baseline 0.97+0.08 1.01_+0.21 Insulin 1.43_+0.09 0.66+0.13 Although FDG-MR were significantly smaller than H-3 glucoseMR after insulin in the Langendorff hearts, there was a significant correlation between FDG and H-3 glucose-MR values (r=0.87, p<0.05). Baseline MR of both tracers were significantly higher in the working hearts compared to Langendorff hearts (p
Simultaneous F18/Tc99m Dual Isotope PET/SPECT (DIPS) using low energy high resolution collimators (LEHR) would allow registration of high resolution Tc99m SPECT and F18 PET images in one imaging session, an improvement over low resolution, low sensitivity dual isotope collimated SPECT. Phantom studies were done on a Picker PCD (3/4") to 1)Compare F18 image quality with and without LEHR. 2)Model the F 18 cross-talk contamination (FCTC) in the Tc99m window. 3)Derive a cross-talk correction algorithm (CTCA) 4) Test the DIPS protocol on a cardiac phantom with clinical activities of Tc99m and F 18 in the myocardium and background and small ant and inf wall inserts (lxl.8cm). The F18 images showed the same image quality with and without LEHR. The FCTC produced severe noise artifacts in the processed Tc99m images affecting interpretation. Application of the CTCA removed >98% of the FCTC showing clean slices and revealing the small "defects". Thus simultaneous high resolution high sensitivity DIPS imaging appears feasible and, compared to collimated SPECT, should improve the localization and assessment of viability in areas otTc99m perfusion defects with lower doses of F18(FDG).

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Abstracts Monday afternoon, April 19, 1999

Journal of Nuclear Cardiology January/February 1999, Part 2

13.4 M O N D A Y P M A P R I L 19

13.6

SESTAMIBI UPTAKE ACCURATELY PREDICTS MYOCARDIAL VIABILITY IN A CANINE MODEL OF CORONARY REPERFUSION WITH A SEVERE RESIDUAL STENOSIS

K. Takehana, M. Ruiz, F.D. Petruzella, D.D. Watson, G.A. Beller, D.K. Glover University of Virginia, Charlottesville,

USA.

Detection of infarct zone viability early after reperfusion (Rep) is often complicated by the presence of a severe residual stenosis. To determine whether 99mTo-sestamibi (MIBI) uptake accurately detects myocardial viability in this setting, 8 dogs underwent total LAD occlusion for either 40 (Grp I) Or 90 (Grp 2) min. Infarct sizes averaged 9% vs 51%, respectively (p<0.01). MIBI was injected 30 min after Rep through a flow limiting stenosis (LAD flow=58% normal). LV wall thickening (WT) was then measured during dobutamine (Dob) stress after total LAD Rep. MIBI defect magnitude (LAD/LCX count ratio) from e x v i v o imaging was significantly lower in Grp 1 (0.71±0.03) vs Grp 2 (0.42±0.05) dogs (p<0.01). The greater degree of viability in Grp 1 was confirmed by greater improvement in contractile function during Dob (WT:-6 to 20% vs -i to 7%; p<0.01). The clinical implication of these findings is that, despite the presence of a severe flow limiting stenosis, resting MIBI uptake accurately predicted the extent of viable myocardium.

SERIAL EVALUATION OF FATTYACID METABOLISM AND MITOCHONDRIAL FUNCTION IN RAT HEART WITH MYOCARDIAL ISCHEMIA USING PINHOLE SPECT. T.Hirai, R.Nohara, S.Ogou, L.Chin, R.Hosokawa, S.Taguchi, Y.Fujibayashi, S.Sasayama, Kyoto University, Kyoto, Japan '231-r-iodophenyl-3-(R,S)-methylpentadecanoic acid (BMIPP) is mainly trapped into the myocardium as triglyeeride depending on ATP level, and 10 to 20 percentage of it is metabolize(] through c~- and /3-oxidation. Thus, BMIPP imaging may_ reflect the mitochondrial function. Dual SPECT images of BMIPP and Thallium-201 (TI) were taken three days (acute stage) and 24 days (chronic stage.) after a transient left coronary artery occlusion (<30 mm.) (Wistar Kyoto rat, n=14). After taking the last images the rat hearts were excised and the activity of 3-hydroxyacyI-CoA dehydrogenase (HAD) and citrate synthase (CS) was measured in both ischemic (anterior) and normal (posterior) region. BMIPP- and TI-SPECT images were evaluated as tile defect scores (DSB and DST). Then the mismatch scores (MS) were calculated as follows; MS=DSa-DST. The rats were derided into two groups depending on the MS in acute stage (MSA); group A: MSA~3 group B: MSA%2. In group A the DST in chronic stage mproved better than those n group B (group A 80%(4/5) group B 33.3%(3/9) p=0.12). In ischemic reg ons, CS was 100.6_+28.4 mmoleslg/m n and HAD was 44.6-+23.2 mmoles/g/min. These values were significantly lower than those in normal region (p<0.01 CS:151.6_+42.7 HAD:74.5_+22.9). DSB in chronic stage were correlated wel with HAD and CS activity (r=-0.73 and -0.76 p<0.01 respectively). These resuts nd cate that there s a c ose relationship between the BMIPP imaging and the activity of HAD and CS, suggesting that decrease in BMIPP uptake reflects deteriorahon of both fatty acid metabolism and citrate cycle. In conclusion mitochondrial function in ischemic rat heart can be assessed non nvas vey and serially by BMIPP imaging using pinhole SPECT system.

13.5

14.1

THE EFFECT OF REPETITIVE ISCHEMIA ON CONTRACTILE FUNCTION, MYOCARDIAL BLOOD FLOW AND OXYGEN CONSUMPTION. KF Kofoed, PR Hansen, JD Hove, S Holm, K Chen, J Wen, M Jensen, H Iida, B Hesse, JH Svendsen, S Hanns¢ & H Kelb~ek The Heart Centre, Rigshospitalet, Denmark

WHICH ARE THE OPTIMAL VIABILITY CRITERIA ON FDG SPECT TO PREDICT RECOVERY OF LV DYSFUNCTION POST-REVASCULARIZATION? J.J.Bax, J.H.Cornel, F.C.Visser, D.Poldermans, P.M. Fioretti, A.van Lingen, C.A.Visser. Leiden, Netherlands.

Long-term reversible impairment of left ventricular contractile function may fie associated with near-normal myocardial oxygen consumption and blood flow. We tested whether this pathophysiological state can be induced by _repeated short episodes of ischemia. Methods In an open chest dog model (n=8) a major branch of the LAD was occluded 4 times for 5 minutes alternating with 5 minutes of reperfusion. Regional ischemia and reperfusion flows were measured with Xenon washout. Before and 1 hour after repetitive ischemia regional segmental shortening (ultrasonic crystals), myocardial oxygen consumption (C-11 acetate) and blood flow (O-15 water/O-15 CO) with positron emission tomography was measured. Results During ischemia blood flow decreased to <10% and after reperfusion increased to approximately 200% of the baseline value. One hour after repetitive ischemia segmental shortening was decreased to 40+19% of baseline (.p<0.05) whereas regional myocardial oxygen consumption was unchanged, 0.22+0.02 vs 0.24+0.03 ml/min/g, (p=ns). At this time myocardial blood flow was decreased to 79+7% of baseline, 1.20+0.13 vs 1.61+0.22 ml/min/g (0<005) Conclusion Repetmve episodes of myocardial mchemla induces a state of contractile dysfunction associated with [~reserved oxygen consumption and near-normal blood IIOW.

In this study we sought the optimal viability criteria on FDG-perfusion SPECT imaging to predict improvement of function after revascularization. In 42 patients, 206 dysfunctional segments were divided into 5 groups: I) 37 segments with normal perfusion, II) 69 segments with a mild reduction in perfusion (>60% of normal Tt-201 uptake) without increased FDG uptake (mild match), III) 29 segments with a mild reduction in perfusion and increased FDG uptake (mild mismatch), IV) 46 segments with a more severe reduction in perfusion (<60% of normal T1-201 uptake) without increased FDG uptake (severe match) and V) 25 segments with a T1-201 activity < 60% and increased FDG uptake (severe mismatch). Wall motion improved postrevascularization in groups I, III, V. Group I, III and V had a positive predictive value of 76%, 69% and 68%. Group II and IV had a negative predictive value of 87% and 93%. The results indicate that normal perfusion and mismatch pattern are predictive of functional recovery, while the (mild) match pattern is predictive of absence of recovery.

Journal of Nuclear Cardiology Volume 6, N u m b e r 1, Part 2

Abstracts Monday afternoon, April 19, 1999

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14.2

14.4

P R E V A L E N C E O F V I A B L E M Y O C A R D I U M IN I S C H E M I C CARDIOMYOPATHY A.M. Amanullah, J. Namla, M. Scott Dawson, B.K. Singh, P. Guillo, J. Hen, A.E. Iskandrian. M C P * H a i m e m a n n School of Medicine, Philadelphia, PA, USA

IS VIABILITYIMAGINGREALLY NEEDEDTO PREDICT FUNCTIONAL RECOVERYOFHIBERNATINGMYOCARDIUM?

Previous studies show that reversible perfusion defects (RD) are better predictors o f recovery of regional function after coronary revascularization than mild-moderate fixed defects (FD) in patients (pts) with ischemic cardiomyopathy (ICM). However, survival benefit and improvement of quality o f life m a y depend on total viable myocardium (normal, RD and mild-moderate FD). Thus, we examined the prevalence of RD or any viable myocardium in 92 pts with ICM(64+10 years, M/F 66/26, EF% 27+13), who underwent rest-redistribution T1-201 SPECT and dobutamine Tc-99m sestamibi gated SPECT. A total o f 1,840 segments were evaluated. Presence of rest and stress-induced RD were considered surrogates for improvement in function, whereas presence o f normal per fusion, RD and mild-moderate FD as markers o f total viability (TV). Significant viability was considered present when >_50% of segments in at least 2 vascular territories were present. The prevalence of RD and TV is shown below: LAD LCx RCA RD 40% (37/92) 27% (25/92 59% (54/92) *93% (86/92) *96% (88/92) *83% (76/92) TV *p<0.001 vs. corresponding vascular territory. There were significantly more pts with TV than RD in 2 o f 3 vascular territories [95% (87/92) vs. 30% (28/92), p<0.001]. Thus, in ICM, survival and quality of life benefits are expected in greater proportion of pts than improvement in regional function after revascularization.

14.3 E V A L U A T I O N OF M Y O C A R D I A L VIABILITY OF ACUTE M Y O C A R D I A L I N F A R C T I O N U S I N G TI S P E C T A F T E R

TALIUM-GLUCOSE-INS ULINE INFUSION. T.Toyama, H.Hoshizaki, N.Isobe, N.Takama, N.Koitabashi, M.Nakatsugawa, M.Suguta, T.Hiroi, H.Tada, H.Adachi, S.Naito, A.Nogami, S.Oshima and K.Taniguchi. Gunma Prefectural Cardiovascular Center, Maebashi,Japan. To evaluate myocardial viability of acute myocardial infarction (AMI), we performed Tl and Tc-pyrophosphate (PYP) dual SPECT and T1 SPEC~ after TI with GI (10% glucose 250ml, insulin 5U andKCl 10mEt0 infusion (GI-TI) in 25 initial AMI patients within 10 days after admissiom who all were reperfused successfully. GI-TI SPECT was obtained after GI2'1 infusion (E) and 4 hours later (D). Left ventriculograpyhy (LVG) was done within 3 weeks after admission and at 3 to 5 months later, and follow up (F-up) TI SPF3STwas done at 3 to 5 months later. SPECT image was divided into 20 segments and regional tracer uptake was scored by using a 4-point scoring system (DS; 0 = normal to 3 = defect ), and summedto a defect score(RDS) and calculated the number of reduced uptake segments (ES). The in&rcted area was defined as the Tc-PYP uptake area (ES). LVG was divided 7 segments and wall motion was estimated by using a 6 point grading system ( -1 = dyskinesis to 4 = normal ). Sensitivity and specificity of different imagings in detecting myocardial viability ( DS~2 was viable ) on the basis of the improvement in wall motion were estimated in the 53 infarcted LVG segments of 19 patients without restenosis. 1. The ES and RDS in different imagings. (*:p<0.05 vs Tc-PYP, **:p<0.01 vs Tc-PYP, # p<0.01 vs F-uoTI. $ p<0.05 vs GI-TI (E}] Tc-PYP R-TI GI-TI(E] I GI-TI(D] I F-uoT1 I ES1 7.5--+4.1 5.5+-2.8*# 4.0+-2.3** I 5.6_+2.7"#13.5+--2.8 ** IRDSI 111.3±7.9#$1 7.4+-6.5 111.2+-6.3#$1 7.1+-6.5 ] The ES of GI-TI(E) was smaller than that of Tc-PYP, and near to that of Fup-Tl. The RDS of GI-TI(E) was smaller than those of R-T1 and GI-TI(D), and near to that of F-uD-TI. 2. The sensitivity and soecificitv. Sensitivity R-TI I GI-TI(E) I 75% GI-TI(D) 70% (31/44) 93% (41/44) (33/44] ! Specif c ty 89% (8/9) 78% (7/9) I 78% (7/9) The sensitivity of GI-TI(E) detectin[~ myocardial viability of A/VII was highest among 3 imagings. The specificity of 3 imagings was almost the same. To detect myocardial viability of AMI, GI-TI early imaging is more useful than rest TI imaging.

R.Sciagr~., S.Sestini, M.Pellegri, A.Coppola, G.M.Santoro. Nuclear Medicine, Universityof Florence; Florence, Italy. The likelihood of functional recovery in viable hibernating myocardium is related to duration of hibernation, coronary status and severity of wall motion (WM) abnormality. We examined the capability of these variables alone to predict postrevascularization functional recovery and the additional value of viability detection using Sestamibi SPECT. We studied 53 CAD patients with LV dysfunction and clear WM abnormality in 83 coronary territories. We considered as variables: time from prior myocardial infarction (TMI), % coronary obstruction (OBS), collateral score (CS), regional WM. Viability was assessed on the basis of baseline (B) and nitrate (N) Sestamibi activity and nitrate-induced activity changes (CH). Post-revascularization WM improvement defined the presence of viable hibernating myocardium. Using stepwise discriminant analysis, a function including OBS and TMI correctly classified 55 territories (66%), with 73% negative predictive (NPV) and 62% positive predictive value (PPV). Adding SPECT data, a function including N, CH, TMI, CS, and B correctly classified 64 territories (78%), with 85% NPV and 73% PPV. In conclusion, coronary status and duration of hibernation are important parameters, but imaging data are needed to achieve a reliable and accurate prediction of post-revascularizationrecovery of asynergic coronary territories.

14.5 RECOVERY OF REGIONAL LEFT VENTRICULAR DSYFUNCTION AFTER BYPASS SURGERY AS D E F I N E D BY Q U A N T I T A T I V E M R I IMPACT OF PREOPERATIVE TC-99M TETROFOSMIN SPECT. J.C. Stollfuss, J. Neverve, *F. Haas, S. Nekolla and M. Schwaiger. Department of Nuclear Medicine, Klinikum rechts der Isar, Technische Universit~it Miinchen, Munich, Germany, * Heart Center, Munich, Germany. Tc-99m labeled flow tracers may provide indices of tissue viability based on myocardial activity retention. The purpose of this study was to evaluate the predictive value of Tc-99m-Tetrofosmin uptake at rest for regional functional recovery. Regional tracer uptake in 18 patients was correlated to regional wall thickening (WT) assessed by a modified centerline approach using corregistered gated short axis M R images prior and 4.5_+0.8 months after surgery. Normal WT values (mean+SD) were derived from 18 healthy volunteers (5.6_+0.9mm anterior segments, 7.0--1.2mm lateral, 6.9_+1.4mm inferior). Analysis was performed on 82 segments with preexisting moderate WT abnormalities (exceeding -1.0 SD below normal). Left ventricular ejection fraction pre-revascularisation was 32+11% and increased to 39+12% post-revascularisation (p<0.02). WT improved from -3.4+1.7SD to -2.2_+3.0SD after bypass surgery. The positive and negative predictive value for Tetrofosmin uptake were 0.57 and 0.82, respectively (>50% of peak activity, WT improvement >-I.5SD). The sensitivity and specificity was calculated to be 0.93 and 0.33, respectively. The overall diagnostic accuracy of Tc-99mTetrofosmin SPECT, expressed as the area under ROC curves, was 0.64+-0.07. We conclude that Tc-99m-Tetrofosmin SPECT has a high sensitivity (negative predictive accuracy) but limited specificity (positive predictive accuracy) for prediction of regional functional recovery after bypass surgery.

M O N D A Y P M A P R I L 19

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M O N D A Y P M A P R I L 19

Abstracts M o n d a y afternoon, April 19, 1999

Journal of Nuclear Cardiology January/February 1999, Part 2

14.6

15.2

Myocardial viability in severe left ventricular dysfunction: a head4o-head comparison between dobutamine stress echocardiography and 99mTc-tetrofosmin/FDG SPECT.

INCREMENTAL PROGNOSTIC VALUE OF PEAK STRESS EJECTION FRACTION OVER SPECT IN PATIENTS POST-REVASCULAR/ZATION. E.A. Dubois, D.S. Berman, H.C. Lewin, I. Cohen, J.D. Friedman, L.J. Shaw, R. Hachamovitch. Cedars-Sinai M.C., L.A., CA. We investigated the incremental value of peak exercise ejection fraction (FPEF) for the prediction of hard events (HE; cardiac death or myocardial infarction) in patients (pts) with prior revascularizations (REV) by performing (FU) in 2015 pts who underwent REV and subsequent rest Tl-201/stress Tc-99m sestamibi SPECT (69% exercise stress, mean age 68 4- 11; 76% male). During a mean FU of 1.8 ± 0.5 years 120 HE occurred. FPEF measurement was performed randomly in 874 of these pts. SPECT was scored visually using 20 segments/5-point scale. SSS: Z stress scores; SSS < 4 is normal (nl), 4-8 mildly abnl, SSS > 8 severely abnl (SEV). Mean FPEF 57 4- 13%, mean SSS 11 4- 10. Pts with nl FPEF and SEV had a lower HE rate than pts with SEV and no FPEF (2.8% vs. 13.3%, p<0.005). Multivariable Cox analysis revealed added value of SPECT over clinical and historical pts data (X 2 52 to 75, p<0.001) and further increased with FPEF data (X 2 84, p<0.001). Thus, FPEF can identify pts with REV at low risk despite abnl SPECT.

D. Poldermans, J.J. Bax, R. Valkema, W.B. Vletter, P.M. Fioretti, J.R.T.C. Roelandt. Thoraxcenter, Erasmus University, Rotterdam,

The Netherlands. Aim: Dobutamine stress echocardiography (DSE) was compared with dual isotope simultaneous aquisition (DISA) SPECT with 99mTTc-tetrofosmin/fluorine 18-fluorodeoxyglucose for assessment of myocardial viability. Methods: 70 pts (mean age 55 + 9.5 yrs) with LV dysfunction (mean ejection fraction 27 + 13%) underwent both DISA-SPECT and DSE. Both echo and DISA-SPECT data were analyzed using a 16-segment model. Viability criteria were normal perfusion or mismatch pattern on DISA-SPECT and bi-phasic response, ischemia, and late or sustained improvement on DSE. Results: Of 1104/1120 evaluable ventricular segments, 599(54%) had severe wall motion abnormalities at baseline. Viable segments during DSE were 161 (27%): 20(3%) bi-phasic response, 33(6%) ischemia and 108(18%) late or sustained improvement. Nonviable segments were 438(73%). By DISA-SPECT, 182(30%) segments were considered viable and 417(70%) nonviable. Segments viable by both techniques were 125/161 (80%). The different DSE patterns of viability corresponded with DISASPECT assessed viability by: hi-phasic response 13/20(65%), ischemia 22/33(66%), and late or sustained improvement 75/108 (69%). The overall agreement was 77% on a segmental basis, 77% on a patient basis and 75% in a subgroup of 23 patients with EF <25%. Conclusions: We found a high correlation for detection of viable myocardium on both segmental and patient basis by DSE and DISASPECT.

15.1 PROGNOSTIC VALUE OF THALLIUM-201 MYOCARDIAL SINGLEPHOTON EMISSION COMPUTED TOMOGRAPHY (TL-SPECT) AFTER CORONARY ARTERY GRAFT SURGERY (CABG). L. Sarda, L. Fuchs, R. Lebtahi, N. Delahaye, R. Genin, P. Assayag, P.G. Steg, M. Faraggi, D. Le Guludec. H6pital Bichat, Pads, France. TI-SPECT is of strong prognostic value in different populations with suspected or known coronary artery disease. However, its value in patients with CABG is not fully assessed. We retrospectively examined in 115 consecutive pts the relation between stress TI-SPECT performed more than 12 months (mean : 84+48) after CABG, and futur cardiac events (hard events: cardiac death and myocardial infarction, soft events: revaseularization procedures). A stress-4 hrs reinjection acquisition sequence was performed after exercise in 47 pts, dipyridamole infusion in 12, and combined test in 56. Were considered: clinical data, stress ST segment depression, stress TI lung uptake, and extent of stress TI defect (TD) expressed as the number of abnormal segments (total segments=13). Follow-up duration after scintigrephy was 35+22 months. Results: There were 9 cardiac deaths, 7 non fatal myocardial infarctions, and 17 revascularizations. Multivariate stepwise Cox regression procedure identified age of grafts at the time of scintigraphy (p=0.02, Relative risk (RR) :1.01), the extent of TD (p=0.05, RR :1.17, %2 increment : 4.16) and increased stress TI lung uptake (p=0.04, RR :3.6, Z2 increment : 3.40) as significant predictors of hard events. Only age of grafts (p<0.001, RR :1.01) and the extent of TD (p=0.03, RR:1.15, %2 increment: 4.3) were significant predictors of hard/soft events. Conclusion: Besides the age of grafts, the extent of TD and increased stress TI lung uptake were the only significant and additive predictors of cardiac events in 115 patients with CABG performed more than 12 months before TI scintigraphy.

15.3 SPECT MYOCARDIAL PERFUSION AND CLINICAL EVALUATION AFTER PTCA Ed~iges Prazeres-S& Pedro Abreu, Jos6 Loureiro, Lucflia Salgado, Ana Teresa Fonseea, RatZael Ferreira ttospital Femando Fonseca - Amadora - Portugal There is n high risk of restenosis aRer PTC.& specially after complex procedures. Follow-up should include a non-ivasive technique for detection of myocardial ischernia (I), as SPECT myocardial peffusion scintigraphy. ?din ot'the study: 1) detection of I extension and relation to clinical events and reslenosis; 2) evaluation of I at di.~nee due to inconrplete revaseularization 0ne Revase); 3) prognostic value of sealaJ-quantitative analysis of nec'rosis (N) associated to I and extra-myocardial SPECT indices. Patie~ats and methods: 70 patients (pt) submitted tc~ PTCA with a tbllow-up of 6-26 months (457+_150 days) were studied, aged 31-76 (58,6+_9,0), 56 male; 49 had acute myocardial infar~ion (,~MI), 5 unstable angina CUA)p~x~t-~MI, 10 UA withottt AMI, 6 stable angina; 1 vessel disease (VD) was present in 54 pt, 12 had 2 ~q), 2 had 3 VD and 2 left main disease post-CABG; Revasc was complete in 64 of 70 pt, and stents were place in 56. Pt ~ere clinically evaluated at 1; 2 and 6 months and thallium SPECT was doue at 4-6 months (148_+45 days). A semi-quantitative 16 segments (sg) analysis was used tbr SPECT and the number ofsg with I, N, viability (V), N+V and N+I as welt as LV dilatation, lung and RV uptake was considered. Results: 1) 60 pt were free of symptoms during follow-up; 13 major cardiac events (18.5%) occurred (3 UA, 9 re-PTCA - 1 late PTCA, 1 death); 2) 30 of 70 pt (42.8%) had SPECT with no I - 13 normal, 5 N, 4 N+V, 8 V; 3 were reeath due to atypical daest pain (1 SPECT normal, 2 V ) and reste~aoseexcluded; 1 pt had late angina, restenosis and re-PTCA at 9 months follow-up; 3) 30 pt had I at PTCA area, 19 ha less than 4 sg (3 had stable angina, 1 UA, 7 recath, 3 restenosis and re-PTCA) and 11 in more than 4 sg (5 stable angina, 3 recath, 3 restenosis and re-PTCA)" 4) 6 pt had I at distance (3 me revasc occmved, 2 UA, 2 new PTCA of other vessel, 1 progression of disease); 5) 4 pt had large N at SPECT (n>5 sg) + small I areas, LV dysfimction (1 pt had re-AMI and death at 9 month, 1 had re-eath with no restenosis). Conclusions5 1) No early (<9 months) major events in the no-I group at SPECT; 2) Major events in 7 of 30 pt with I at the PTCA area; 3) Assymptomatic pt with small areas of i at PTCA area had no major events.

Journal of Nuclear Cardiology Volume 6, Number 1, Part 2

Abstracts Monday afternoon, April 19, 1999

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15.4

15.6

THE EARLY PREDICTION BY DIPYRIDAMOLE THALLIUM201 IMAGING OF LATE RESTENOSIS AFTER PTCA: IS IT AN ACCURATE APPROACH ? A. Belloni, A. Colombo, B. Palagi*, S. Boccolari*, R. Picozzi* Division of Cardiology - Hospital "L. Sacco" - Milan Laboratory of Nuclear Medicine - Hospital of Saronno - Italy

D E T E R M I N A N T S OF D E C I S I O N T O P E R F O R M E A R L Y CORONARY REVASCULARIZATION AMONG PATIENTS U N D E R G O I N G Tc-99M S E S T A M I B I G A T E D S P E C T

Aim of the study: aim of our study was to assess the accuracy of dipyridamole thallium-201 single photon computerized tomograpby (DIP-SPECT) in evaluating the completeness of the revascnlarization and, together with other possible clinical variables, in predicting late restenosis in patients examined early after a successful PTCA of single vessel coronary artery disease

Among CAD patients undergoing cardiac catherization (CATH), the amount of inducible myocardial ischemia, angiographic CAD extent, and resting left ventricular (LV) ejection fraction (EF) are important determinants of early coronary revascularization (ECR). We compared gated SPECT perfusion and LV contraction parameters versus known CATH and clinical predictors on the decision to refer patients for ECR in 268 CAD (> 50% stenosis) patients (age 624-12, 59% male) undergoing SPECT and CATH. 79 patients (48 PTCA; 31 CABG) underwent ECR <60 days following SPECT. Studies were read using a 20-segment, 5-point scale of perfusion (0--normal to 4=no uptake). Global summed reversibility (SRS) and summed fixed (SFS) defect scores were calculated as measures of ischemia and scar, respectively. Multiple logistic regression analysis was performed to assess the following as predictors of ECR: age, gender, diabetes, prior MI, LVEF, angiographic CAD extent, SRS, and SFS. Only SRS (p=0.008) and angiographic CAD extent (p=0.047) were significant independent predictors of ECR. SRS ranged from 0 to 50, and SRS >10 increased the probability of ECR 1.2 to 5.3 times (95% confidence interval). Conclusions: The amount of reversible jeopardized myocardium quantitated by SPECT imaging superceded angiographic CAD extent as the most significant predictor of ECR in CAD patients.

(CAD). Methods: the patient population consists of 70 consecutive cases studied by DIP-SPECT 8-4-5 days after a successful PTCA of single vessel CAD who were clinically followed up and underwent repeat coronary angiography within one year of the PTCA. Results: fifteen (21%) of 70 patients complained of angina during follow up. Late restenosis was observed in 29 (41%) of 70 cases. Of the clinical and angiographic variables, only recurrent angina occurred more frequently in the cases with than in those without restenosis (48% versus 2%; p< 0.00002). Reversible perfusion defects in the supply region of the dilated coronary artery were observed in only 17 (24%) of 70 cases. Late restenosis was demonstrated in 8 (47%) of 17 cases with reversible perfusion defects and in 21 (40%) of 53 cases without reversible perfusion defects (p= NS). Conclusions:early DIP-SPECT after PTCA cannot accurately predict late restenosis, a biologic process evolving through months even after a mostly complete revascularization.

15.5 DECISION FOR P E R C U T A N E O U S T R A N S L U M I N A L CORONARY ANGIOPLASTY (PTCA) AND PREDICTION OF ITS OUTCOME: ROLE OF STRESS MYOCARDIAL SPECT SCINTIGRAPHY. Oommen R, Salman H, Hayat N, Tuli M, Shukkur M, Mohannadi S, Bouresly S, Baig S, Cardiology & Nuclear Medicine Departments, Chest Hospital & Faculty of Medicine,Kuwait University Kuwait. Percutaneous transluminal coronary angioplasty (PTCA) has become a highly popular method for coronary revascularisation. The role of stress myocardial scintigraphy (MS) was studied in deciding for PTCA in patients(pts) with significant coronary artery disease(CAD) and predicting the outcome. The study group comprised 68 consecutive pts with (CAD ( )>70% luminal narrowing( who underwent PTCA, and stress MS. Stress test was done using Bruce protocol;pts were injected with Tc99mtetrofosmin followed by SPECT imaging. Out of 47 pts with stable angina and reversible perfusion defects on MS, who underwent successful PTCA, )lesion reduced from 70-90% to <30 %(, 41 pts had regular follow up )mean 20 months(. 37/41 were asymptomatic,with normal MS and 4 pts had recurrent angina.requiring re-PTCA The remaining 22 pts (Group II) with unstable angina underwent PTCA without prior stress MS, 18 were available for follow up )mean 18 months(. 16/18 had slress MS because of atypical chest pain; 13 of them with no ischemia did not have further cardiac events )mean follow up 18 months(. 3/18 with recurrence of angina and ischemia on stress MS showed re-stenosis on repeat angiography, and underwent succesful rePTCA. Conclusion: Stress MS is a useful non-invasive tool for indicating patients with stable angina for PTCA. It also helps predicting prognosis and outcome during follow up.

&S. Yao, W. Paimas, A. Burnstein, K. Nichols, E.G. DePuey, A. Rozanski. St. Luke's-Roosevelt Hospital Center and Columbia University, New York, NY.

15.7 COMPARISON OF DYPYRIDAMOLE AND EXERCISE DUAL ISOTOPE SPECT FOR DETECTING RESTENOSIS AFTER ANGIOPLASTY. E. A. Iliadis, A. Ali, J. T. Barron. Rush Medical College, Chicago,

IL, USA. To compare the predictive abilities of dypridamole (DP) and exercise (EX) SPECT imaging for detecting restenosis post angioplasty, stress ECGs and 201 T1 rest and 99m Tc stress SPECT images of 130 DP and 179 EX stress tests were analyzed. Coronary angiography was performed within 1 year post angioplasty. Results: Therewas no difference in the ability to detect restenosis when comparing the DP or EX ECG alone (p=ns). Analyzing all DP and EX SPECT exams, EX SPECT was more predictive of restenosis in the left anterior descending (LAD) distribution (p=0.0038) while DP SPECT was more predictive in the left circumflex (LCX) distribution (p=0.069). No modality was predictive in the right coronary artery (RCA) distribution (p=ns). However, if performed within 90 days of angioplasty, DP SPECT was superior to EX SPECT in detecting restenosis in LAD (p=0.015 vs p=0.59) while equivalent in the LCX (p=0.0008 vs p=0.0081) and RCA (p=0.020 vs p=0.01) distributions, respectively. Evaluating the combinationof positive ECG changes and reversible perfusion defects, DP vs EX SPECT predicted restenosis in the LAD (p=0.97 vs p=0.10), LCX (p=0.096 vs p=0.0075) and RCA (p=0.096 vs p=0.051) distributions, respectively in favor of EX SPECT. Conclusion: At one year, EX SPECT was superior to DP SPECT in detecting restenosis. If performed within 90 days of angioplasty, DP SPECT is superior to exercise SPECT in predicting restenosis. Timing of stress and lesion location should influence study seleetion.

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Abstracts Monday afternoon, April 19, 1999

15.8 M O N D A Y P M A P R I L 19

Tc-99m TETROFOSMIN MYOCARDIAL PERFUSION SCINTIGRAPHY TO DETECT RESTENOSIS AFTER STENT IMPLANTATION and PERCUTANEOUS CORONARY ANGIOPLASTY (PTCA) B.De~irmenci, 0. Klnmh, R. Beki~, G.~apa, E.Derebek, 0. Gtldeli, H. Durak, S.Gtineri. Dokuz EyliJl University Hosp,, tzmir,Turkey. Evaluation of the restenosis after stent implantation and successful PTCA is an important point on follow-up coronary artery disease. The purpose of this study was to investigate the diagnostic accuracy of myocardial perfusion SPECT (MPSPECT) in detecting restenosis after stent implantation and successful PTCA. Stress and rest MPSPECT studies were performed using Tc-99m tetrofosmin as a same- day protocol to evaluate 27 vascular territories with implanted coronary stents (24) and PTCA (3) in 25 patients (18 male, 7 female). The patients did not have MPSPECT study before PTCA and stent implantation.The interval period between stent implantation/PTCA and MPSPECT study was 3 to 6 months.The scans were evaluated visually and semiquantitatively. Coronary angiography was performed in all patients for final diagnosis. Coronary angiography revealed a stenosis of 50% diameter in the region of the stent in 6 arteries, while in 21 arteries there was no evidence of restenosis. With MPSPECT, 5/6 vascular territories with restenosed stents showed stress induced ischemia (sensitivity:83%), while 2/21 territories without restenosis did not (specificity:91%). Positive-predictive, negative-predictive values and accuracy of the MPSPECT were calculated 71%, 95% and 89% respectively. This ongoing study suggests that Tc-99m tetrofosmin MPSPECT may be a noninvazive test in detecting restenosis after stent implantation and successful PTCA, even in the absence of pre-PTCA perfusion study.

Journal of Nuclear Cardiology January/February 1999, Part 2

15.10 SPECIFICITY OF ~mTc-TETROFOSMIN EXERCISE SPECT EARLY A F T E R STENT I M P L A N T A T I O N J. Castell, J. Candell-Riera, J. Rod,s, M. Soler, J. Carballo, E. Larrouse, S. Aguad~, D. Ortega, J. Soler-Soler. Hospital General U n i v e r s i t a r i Vall d'Hebron, Barcelona, Spain.

A high number of "false positive" ~ITI reversible perfusion defects early after balloon angioplasty have been reported. In order to evaluate the specificity of maximal exercise ~mTc-tetrofosmin myocardial SPECT perfusion early after stent implantation, 25 patients ( 7 women, mean age: 56.8 years), with one-vessel coronary artery disease (16 LAD, 5 CX and 4 RC) and without previous myocardial infarction, were studied during the first week after succesful stent implantation (reference diameter: 3.11±0.54, minimal lumen diameter: 2.85±0.46 mm, and residual stenosis: 9.62±9.51%). There were 3 false positive studies: 1 LAD, 1 CX and 1 RC (Specificity: 88%) and no differences were observed in the extent of reversibility (rest u p t a k e - e x e r c i s e uptake > 10%) in polar map between the patients with stent in LAD (5.46±5.68%), CX (5.36±5.76%), and RC (4.37±7.78%) and a control group of 74 individuals (55±9 years, 49 women) with normal coronary angiography (9.4±12.9%, 7±9% and 11±13% respectively, NS). Thus, we found a substantial specificity of early maximal exercise ~ T c - t e t r o f o s m i n myocardial SPECT early after successful coronary stent implantation.

15.9

15.11

STRESS SPECT P E R F U S I O N I M A G I N G IN E V A L U A T I O N OF G R A F T P A T E N C Y LATE A F T E R C O R O N A R Y A R T E R Y BYPASS GRAFT SURGERY J. Castell, J. Carballo, J. Candell-Riera, S. Aguad~, E. Larrouse, M. Soler, C. Santana, A. Garc~a-Burillo, J. Soler-Soler. Hospital General U n i v e r s i t a r i Vall d'Hebron, Barcelona, Spain.

SAFETY AND UTILITY OF NUCLEAR PERFUSION IMAGING IN PATIENTS STATUS POST CORONARY ARTERY STENTING.

The goal of this study was to d e t e r m i n e the diagnostic yield of exercise m y o c a r d i a l single photon emission computed t o m o g r a p h y (SPECT) with 99mTc compounds for detection of occluded coronary artery bypass grafts (CABG). In 36 symptomatic patients (33 men, mean age: 63 years), 67 CABG (35 LAD, 16 CX and 16 RC) were evaluated with exercise myocardial SPECT (15 with ~ T c - M I B I and 31 with ~ T c tetrofosmin, 6 with simultaneous submaximal exercise plus dipyridamole) and coronary angiography. Sensitivity (73%), specificity (93%), positive predictive value (86%), negative predictive value (84%), positive likelihood ratio (10.4), and negative likelihood ratio (0.29) of SPECT for identification of occluded CABG were higher than those obtained by exercise test alone (50%, 40%, 38%, 51%, 0.83 and 1.25 respectively, p=O.Ol). Thus, exercise myocardial SPECT with ~mTc compounds has a high diagnostic efficacy for detection of occluded CABG.

William A. Van Decker, Ali N. Khan, Sandra L. Norton, Patricia M. McNelis. Allegheny University of the Health Sciences, Philadelphia, PA. Background: The safety and utility of nuclear perfusion imaging in patients status post coronary artery balloon angioplasty (PTCA) for re-stenosis and follow-up has been well documented. Less data is available about the use of perfusion imaging status post coronary artery stenting which has become so popular. Methods: We searched our database for 877 patients with stents (7•95-9•97) to see who also had a nuclear perfusion study post stent placement looking for safety of study and insights to clinical utility. Results: Identified were 114 pts.(13%) having 150 studies (70 male, 44 female; age 61 + 12) with mean post stent follow-up of 13 + 6 months. Of 114 Lots. (22% diabetic, 53% hypertensive, 61% hypercholesterolemic, and 53% with prior MI), 124 studies (83%) were done for a chest pain syndrome. Pharmacologic stress occurred in 83 studies (25 < 1 week, 43 < 6 months, 15 > 6 months) of which 13 had scan ischemia at stent site. The remaining 67 studies had exercise stress (6 < 1 week, peak heart rate 107 + 19; 61 > 1 week, peak heart rate 137 + 23) of which 9 had stent site ischemia. Total 22 (15%) were scan positive and management plans were formulated on scan results. No nuclear procedural Ml's or deaths occurred: Conclusion: 1) Nuclear perfusion stress testing is safe in the poststent population. 2) Utility for detecting stent restenosis appears good.

Journal of Nuclear Cardiology Volume 6, N u m b e r 1, Part 2

Abstracts Monday afternoon, April 19, 1999

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15.12

15.14

SERIAL EVALUATIONS OF THE PATENT CORONARY ARTFALIAL BYPASS GRAFT USING S3RESS "IL-201 SCINHGRAPHY. H.Nagamatsu, H.Kobayashi, H.Ikegami, M.Momose, K.Kusakabe, T.Ohkawa, H.Kasaunki Tokyo Women' s Medical University, Tokyo, Japan

INFARCT SIZE DETERMINED WITH THALLIUM SPECT IMAGING IS AN INDEPENDENT PREDICTOR OF APPROPRIATE DEFIBRILLATOR (ICD) THERAPY J. De Sutter, R. Tavemier, C. Van de Wiele, G. De Backer, L. Jordaens, R. I)ierckx~ University Hospital, Gent, Belgium.

Redistrbution of Thallium-201(Tl) imaging has been relxa'ted to be seen in the graft related territory in spite of the patency of the graft. The purpose of this study is to assess whether the redistribution disappear in the follow-up study. Fifteen patients(12 males, 59-1-8 years old) who had the T1 re~stribution despite of the pateucy of internal thorneie mery(ITA) bypass graft at the initial study after CABG were enrolledin this study. All underwent CABG with 1TA to left anterior descendng aaa'y or diagonal branch. Number of graft is 2 . 2 + 0 . 7 . Stress Ti scintigraphy were perfonned at the follow-up period(46 + 28month after CABG). In 13 patients, T1 rettstribution had disappeared in the follow-up study(Group A). Retlstribution still remainedin 2 patients(Group B). The follow-up periods was not statistically citferent between 2 groups(Group A ; 5 0 + 2 8 months vs. Group B ; 1 6 + 6 months, NS). Eight patients of CrroupA were followed for more than 48 months aid all of group B for less than 24 months. The T1 redstribution at the patent graft rdated territory cisappearedfor 24 months in most cases. To assess the 1TA patency, stress T1 scintigaphy may be performed more than 24 months after CABG.

Data on the relation between the extent of scarring on perfusion imaging and the incidence of appropriate ICD therapy after ICD implantation are scarse. We studied 56 consecutive patients with coronary artery disease (CAD) and vantricular taehycardia (VT) or fibrillation (VF) before ICD implantation with stress-redistribution Thallium SPECT, A defect score (371DS, representing scar tissue), based on the number and severity of fixed defects, was determined using a 17 segment and 5 point scoring system (0 : normal to 4 : severely reduced uptake). After a mean follow-up of 470 days patients with (n=22) and without (n=34) appropriate ICD therapy were compared. In uinvariate analysis VT as presenting arthythmia0 T1 DS and 13-blockers at discharge were predictors of appropriate ICD therapy. In a multivariate regression analysis, V'f and T1 DS remained significant predictors (Z2 5.51, p=0.02 for VT and Z2 4.42, p=0.04 for TI DS with Z2 3.2, p=0.07 for 13blocker therapy). Kaplan-Meier arrhythmia-free survival curves for patients with TI DS<20 (n=31) and T1 DS>_20(n=25) are shown in the figure. ~

~

TI deled < 20 (n=31)

50

p = 0.02

E "Rdefect Z 20 (n=25) (3-

750

1000

1250

days

Conclusions : The extent of scarring assessed with perfusion imaging is an independent predictor of appropriate ICD therapy.

15.13

15.15

RESIDUAL ISCHEMIA DOES NOT INFLUENCE RECURRENCES OF VENTRICULAR ARRHYTHMIAS (VA) AFTER DEFIBRILLATOR (ICD) IMPLANTATION. J.De Sutter, R.Tavernier, C.Van de Wide, J.De Backer, L.Jordaens, R.Dierckx. University Hospital, Gent, Belgium.

IN PATIENTS WITH CORONARY ARTERY DISEASE (CAD) AND VENTRICULAR TACHYCARDIA (VT) OR FIBRILLATION (VF), QT DISPERSION IS NOT RELATED TO MYOCARDIAL INFARCT (MI) SIZE J. De Sutter, R. Tavemier, C. Van de Wiele, J. De Backer, A. Van den Eeckhaut, R. Dierckx, L. Jordaens. University Hospital Gent,

Although acute ischemia is a trigger for VA, it is not clear if residual i~hemia at implantation of an ICD influences the occurrence of new episodes of ventricular tachycardia (VT) or ventricular fibrillation (VF). We studied 49 patients (mean age 67±8 years, 47 men) with coronary artery disease (CAD) and VT or VF who were ~eated with an ICD and not revascularised at implantation or during follow-up. Before ICD implantation, the amount of ischemia was determined on a Thallium stressredistribution SPECT study, using a 17 segment model. Significant isehemia was defined as 2 or more segments showing reversible perfusion defects. 18 (37%) patients had signfficunt isehemia and were considered to have residual ischemia (group I). 31 (63%) showed no significant ischemia (group I0. After a follow-up of 4505:320 days, 21 (43%) patients had a recttrrence of VT or VF. However, no difference was seen between group I and II (44% versus 42%, p=ns). Kaplan-Meier plots for the arrhythmia free survival are 100 shown in the figure. ischemic segment~

Ik

O

250

500

750

1000

1250

days

In conclusion, residual ischemia at the time of ICD implantation does not influence the reeeeurence of ventricular atrhythmias in patients with CAD and life-threatening ventricular arrhythmias.

Belgium. We evaluated if QT dispersion (QTd), which is believed to reflect regional differences in repolarisation, is related to the extent of myocardial damage. We studied QT parameters (QTmax, QTernax and QTd) derived from a simultaneous 12 lead ECG (50 mm/sec) in 40 patients (age : 66 ± 9 years) with CAD and VT or VF. MI size was evaluated with ejection fraction (EF) and eehecardiography ( left ventrictflar end diastolic diameter : LVEDD). Also, a quantitative stress-rest TL-SPECT was performed. A defect score, based on the number and severity of fixed defects, was determined using a 17 segment and 5 point scoring system. Correlations between QT and infarct size parameters are shown in the table.

EF (%)

LVEDD (ram) TI defect score

(45±17) (61+9) (18±11) QTmax(ms) r=-0.1 r=-0.02 r=0.01 (440 ± 50) (p = 0.55) (p= 0.92) (p = 0.98) QTcmax Ons) r = - 0.29 r = - 0.11 r = 0.03 (475 ± 46) (p = 0.11) (p = 0.52) (p = 0.88) QTd 0us) r = - 0.25 r = - 0.01 r = 0.24 (46 ± 19) (p = 0.16) (p = 0.96) (p = 0.22) Conclusions : There is no relation between QT parameters and measures of infarct size in patiems with CAD and VT or VF.

M O N D A Y P M A P R I L 19

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Abstracts Monday afternoon, April 19; 1999

15.16 M O N D A Y P M A P R I L 19

LOCALISATION OF THE ACCESSORY PATHWAY IN WOLFF PARKINSON WHITE SYNDROME: A COMPARISON OF ECG AND RADIONUCLIDE VENTRICULOGRAPHY J Prosser, A Ng, W Martin, A Rankin, I Hutton. Dept.ofMedical Cardiology, Royal Infa-mary, Glasgow, Scotland The site of the accessory conduction pathway in Wolff-ParkinsonWhite syndrome is determined by an electrophysiology study (EPS), prior to radio-frequency ablation (RFA). EPS time could be reduced if non-invasive localisation of the pathway was accurate. 22 patients for rf-ablation underwent gated radionuclide ventriculography (RNVG). Fourier phase images were generated and analysis, by continuous cine loop display of phase masks, was performed by two independent observers to localise the site. A full 12 lead ECG was analysed by a single experienced observer and again, the site determined. Reported pathway sites were expressed in terms of the number of segments away from the actual location, determined by EPS (n=15 segments). Mean values were 0.91 segments for the ECG, 1.27 and 0.95 for the phase images (Observerl and Observer2), respectively. No significant difference was found between phase image and ECG localisation. Lateral sites were identified more reliably by the phase images while right and septal pathways were poorly identified. The ECG was most inaccurate in lateral and posterior sites. Identification of ACP sites from Fourier phase images is a useful adjunct to the standard ECG and may allow identification of multiple pathways.

Journal of Nuclear Cardiology January/February 1999, Part 2

15.18 EASY NUCLEAR DATABASE: A UNIFIED DATABASE ENTRY AND REPORT GENERATION PROGRAM FOR NUCLEAR PERFUSION IMAGING, Renee Fabrizi, Haresh Majmundar, Gregory S. Thomas Mission Internal Medical Group, Mission Viejo CA, USA Methods: A database application using Microsoft Access 97 was developed which allows simultaneous database entry and production of the official report of a nuclear perfusion study. Demographic and procedural information are entered by the technical staff followed by the physician entering the interpretation of the perfusion images. Advanced word processing technology now incorporated into database software facilitates rapid report typing. The report can then be instantly printed or faxed from the computer for immediate use by referring physicians, simultaneously becoming part of the lab database. Results: To date, 2900 patients have been entered into the database using the unified database entry and report form. The database has facilitated the correlation of perfusion scan results with the results of coronary angiography in patients who go on to cardiac cath. Such continuous cath feedback has been shown to enhance the accuracy of test interpretation. The database has also allowed the development of a lab Report Card for referring physicians. Positive and negative predictive accuracy are highlighted in the Report Card as well as other indices such as the gatekeeper function of nuclear cardiology--the rate of cardiac cath in patients with normal scans. Conclusion: A combined database entry and report generation form was developed using off-the-shelf software which eases database development and eliminates the need for preliminary reports and the delays resulting from transcription services.

15.17

15.19

RESTJAE;CARDIACSFBCI'W1Ttt INF[M)GD~J~ ATIENUATION O O R R ~ O N IN P A T I ~ WITH PRIOR INF~IOR MYOCARDIAL INFARCTION

RELIABILITY OF GATED SPECT IN ASSESSING LEFT VENTRICULAR EJECTION FRACTION IN VENTRICLES WITH SCARRED MYOCARDIUM, F. A1-Khori, P. M. McNelis, W.A. Van Decker. Allegheny University of the Health Sciences, Philadelphia, PA.

C .Decker,W.Teichronn*,T.Mmnde Dpts. of Nuclear Medicine and Cardiolog/:", Y~rtin-Luther-University }{~lle-Wittenberg, Germany Aim of the present study was to ~ the effect of inhomogeneous attenuation correction (AC) by simultaneous transndssion-~'on tomography regarding the inferior myocardial uptake in 20 patients with leftventriod~r inferior myocardial infarction (MI) (62,4+/-7,6y.) and 20 controls. After Thallium 201 rest injection a S P ~ was performed using a triple-~d canexa (Picker, 123 Gd line source) and an iterative image reconstruction with and without AC. Maltifactorial a n a l y s i s s h ~ d significant differences in inferior myocardial uptake (p
Background: Gated SPECT (GS) is an often utilized method of assessing global left ventrieular ejection fraction (EF). Theoretical concerns have been raised about the validity of the technique in images with large perfusien defectswhere artificial intelligence extrapolates ventrieular edge detection. Methods: To validate EF calculated by GS in grossly abnormal perfusion images, we comparedthe EF calculatedby GS to EF calculated by first pass method (FP). 42 patients (10 female and 32 male) with known previous myoeardial infarction and severe fixed perfusion defeets of greater than 20% ofmyocardiumby quantitative polar plots. GS EF on ADAC camera, Germano calculation (Germano et al. JNMI995;36:2138-47) with 8 frame/cycle. FP EF on same patients, same day with SIMMS first pass erystal. All tetrofosmin tracer. Results plotted to line of identity with regression analysis and T-testing results. Results:

. ] .

"~

.

.~

a

~

i ,~

//

(GSEF:29d: 8,

i

FPEF:30.4- 7; R=0.81; p = N S )

rP=r

Conclusions: EF can be reliably measured using a gated SPECT program despite severe large fixed perfusion defects on images.

Journal of Nuclear Cardiology Volume 6, N u m b e r 1, Part 2

Abstracts M o n d a y afternoon, April 19, 1999

15.20

15.22

EQUILIBRIUM ECG-GATED TC-99M SPECT RADIONUCLIDE ANGIOGRAPHY (RNA) IN CHRONIC THROMBOEMBOLIC PULMONARY HYPERTENSION (CTE-PH). D. Daou, T. Fourme, F. Parent, O. Sitbon, B.O. HeN, I. Pointurier, A. Benada, A. Prigent, M. Slama, G. Simonneau. UPRES Maladies Vasculaires Pulmonaires. Antoine Beclere Hospital, Clamart, France. Pulmonary artery thromboendarterectomy is becoming an accepted treatment for patients with CTE-PH. We studied in pts referred for preoperative work-up, the clinical, biological and hemodynamic correlates of RV end diastolic (EDV) and end systolic (ESV)indexed volumes and ejection fraction (EF). 23 pts were studied with equilibrium ECG-gated SPECT RNA. Mean total pulmonary resistance (TPR) was 29+11 IU/m2 and mean pulmonary artery pressure (PAP) was 59+15 mmHg. RV EF, estimated EDV and ESV calculated with ECG-gated SPECT-RNA were respectively 37+16%, 135+33 and 83+31 ml/m2. RV-EF, EDV and ESV were moderately correlated to mixed venous oxygen saturation (60+11%) with respectively r=0.5 (p=0.02), r=0.5 (p=0.02) and r=0.6 (p=0.007). EDV was also correlated to the distance walked during the 6ran test (r=0.5, p=0.04). But, there was no correlation with either arterial Po2, PAP nor TPR. In pts with CTE-PH, ECG-gated SPECTRNA may be useful for the evaluation of RV performance and provide complementary information to PAP and TPR.

SCINTIGRAPHIC EVALUATION OF CARDIAC FUNCTIONS IN PATIENTS WITH THALASSEMLA N.0.Kft~ttk, G.Aras, T.Sipahi*, E.ibi~, N.Akar*, A. Soyln, G.Erbay. Ankara Umversity Medical School. Depts. of Nuclear Medicine and Pediatry* Ankara/TORKlYE

$27

It is kamwn that the blood transfusion is necessaly tbr survival in pts with thalassemia. But, it may cause myocardial dysfunction due to myocardial siderosis as in other organs. The aim of this study aas to evaluate myocardial perfnsion using stress thallium scamaing (MPS) and let~ ventricular thnctions using rest radionuclide ventriculography (RNV). Twenty one pts at ages 9-16 (mean 12.1<3.2) have been diagnosed as thalassemia tbr 4.22 years (mean 12.7:k4.8) were included in the study. They had blood transtilsions 78-318 times (mean I62.1±71).MPS and RNV were performed within two days after the any transfusion. MPS showed ischemia in 3 pts and normal perfusion in 18 pts. RNV revealed nonnal systolic parameters (wall motion, EF, PER, TPE) but diminished diastoiic parameters (TPF, PFR) compared to with norlnat values. EF

PFR

PER

rhalassemia 58.6:t:6.9

3.3±0.5

3.1±0.5

117.9--51 21.3±27

Conu'ol

3.8±0.5

3.7±0.7

136.3i21 109.1=25

60.1±81

TPF

TPE

We conclude that ischemia or fixed defects may be seeu in stress MPS as a result of cardiac involvement in pts with thaiassemia. But, RNV is an important aM preferable test lbr the early detection of subclinic myocardiopathy. Because, RNV may show diastolic abnormalities betbre the systolic abnormalities show up.

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15.23

FORWARD CARDIAC OUTPUT MEASUREMENT WITH TC-99M-LABELED PERFUSION AGENTS J. Taki, A. Muramori, K. Nakajima, I. Matsunari, S. Kinuya, Y. Miyazaki, N. Tonami. Kanazawa University

School of Medicine, Kanazawa, Japan.

REGIONAL VARIATION IN INFERIOR WALL MYOCARDIAL PERFUSION DEFECTS WITH PRONE IMAGING. M. Szulc, S. Collins, R. Hachamovitch. N.Y. HospitalCornell Medical Center. N.Y., N.Y., USA.

The aim of this study was to develop and validate a new first pass method for the measurement of forward cardiac output (CO) using 99~Tc-labeled myocardial perfusion imaging agents. To evaluate the new method, 24 patients underwent radionuclide angiogr@hy (frame/see) in anterior view with 600-740 MBq of ~"~rc-tetrofosmin and the measured CO was compared with the CO by the conventional method with 99~Tc-red blood cells (in LAO view). CO by the new method was calculated by the equation; CO= Cm,x'VLv / ~f(t)dt, where Cm,x is the peak count of the whole thorax during angiography, Jf(t)dt is the area under gamma variate fitted LV time activity curve, and VLv is the LV volume obtained by the area length method applied to the radionuclide angiography and myocardiai tomography. The CO by the new method with ~'rc-tetrofosmin (Y) demonstrated a good correlation with the CO by the conventional method (X); Y--0.90X+453 (ml/min), r=0.93. A good agreement between the two methods was observed (mean difference, 73-+390 ml/min). Interand intra-observer correlation coefficients were 0.95 and 0.98, respectively. This new method permits accurate forward cardiac output measurement using the first pass data with 99mTc-labeledmyocardial perfusion agents.

Prone imaging (PR) is often used to enhance cardiac SPECT accuracy in the setting of inferior wall defects. The frequency of change or regional variation in defects with PR is not completely known. We identified 38 patients (pts) (37 male, age 64 + 10) who underwent stress SPECT (3 two day sestamibi, 35 dual isotope) with both PR and supine stress imaging. Both stress images were read blindly by two experience observers using a 20 segment/5 point scoring system. The scores of the inferior, inferoseptum, inferolateral segments for the distal, mid and basal LV were summed. At both the mid and basal LV, a significant improvement in scores occurred with PR (mid: 9.5 _+ 1.6 vs. 8.4 + 1.7; base 9.2 + 1.7 vs. 8.2 + 1.9; all p<0.0001). Overall, 53% of pts had improvement in scores with PR. However, 34% (13/38) of pts had distal inferolateral wall defect worsening. Thus, with prone imaging, significant improvement in counts occur in the mid and basal LV but worsening occurs in the distal LV.

M

O N D A Y P M A P R I

L 19

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Abstracts Monday afternoon, April 19, 1999

Journal of Nuclear Cardiology January/February 1999, Part 2

15.24 M O N D A Y P M A P R I L 19

15.26

LEFT ARM POSITION EFFECT OF ATTENUATION MYOCARDIAL TRACER DISTRIBUTION -

CORRECTION ON

G. Cantinho, H. Pena, A. Veiga, V. Marques, F. Godinho Atomedical - Lab. Med. Nuclear, Lisboa, Portugal inst. Med. Nuclear, Fac. Med. Lisboa, Portugal In cardiac SPECT artifactual abnormalities of regional tracer distribution in the myocardium results from photon attenuation in the chest. However, structures within thorax differ greatly in density. As a result, attenuation correction algorithms are developed in an effort to compensate inhomogeneous photon attenuation. One of the greatest problems is the patient's left arm position. This study evaluates the effect of the arm position and of attenuation correction on regional myocardial tracer distribution on ~mTc-Tetrafosmin cardiac SPECT images. We compared the SPECT stress studies with and without attenuation correction in patients with and without left arm extended above the head. Eleven patients were studied. All the patients performed two stress acquisitions, one in the conventional position, with the left arm above the head and another without it. We considered 4 walls of the left ventricle and apex. All the studies were acquired in an ADAC Vertex gama camera with two heads and high resolution collimator. Gandolinium sources were used for transmission studies. The two acquisitions were processed with (AC) and without (No AC) attenuation correction and with (UA) and without (DA) extended left arm above the head. The mean counts of each wall and apex were obtained and compared, using paired Student T test. Results: When we used the paired Student T test to compare Ac SPECT with UA and DA and No AC SPECT with UA and DA, only the inferior wall is not influenced by the arm position. No AC SPECT UA/DA p=0,6; AC SPECT UA/DA p=0,5. In the anterior, septal and lateral walls, as well as in the apex, the tracer distribution was always different, depending on the arm position and its mean counts differences were not corrected by using attenuation correction. In our results, the arm position was always important and not corrected by the present attenuation correction algorithm. The inferior wall was the only one independent from the arm position. These results indicate that more qualitative and quantitative analyses are needed to correctly validate attenuation correction.

USING LEFT LATERAL IMAGES TO BETTER CLASSIFY INFEROR SPECT DEFECTS Mitchell Saltzberg, Amjad Ali, David Turner, John Barton. Rush Medical College, Chicago, USA. SPECT imaging of the inferior wall (IW) is hampered by attenuation. Left-lateral (LL) planar imaging 1' separation between heart and diaphragm/viscera, thus 1" counts. We hypothesized that using LL images could improve overall SPECT accuracy. Methods: 43 pts had SPECT (2°lTl-rest, 99roTe-stress) and post-stress LL imaging. LL images were read as normal/abnormal. IW SPECT defects were classified as true/false depending on LL imaging, and the resultant sensitivity & specificity were calculated using paired angiographic data. Results: 35/43 pts had > 1+ SPECT IW defects. All 8 pts with normal SPECT scans had normal LL images. LL images were normal in 22/35 (63%) and abnormal in 13/35 (37%) ofpts. With LL imaging, sensitivity $ from 65% to 30%; however, specificity 1"1" from 41% to 69%. Conclusion: When interpreted in conjunction with SPECT, LL imaging $ the false positive rate of SPECT IW defects, improving specificity. This benefit however, comes at the expense of diminished sensitivity.

15.25

15.27

USEFULNESS OF V E N T R A L SPECT A C Q U I S I T I O N IN MALE A. Sandrin, V. Arja, P.Vaudagna, C. Serra, J. Sala, V. Balestrini Instituto Modelo de Cardiologia -C6rdoba-Argenfina.

ATTENUATION CORRECTION AND RESOLUTION RECOVERY IN THALLIUM 201 SPECT STUDIES. R. G6nin, P. Girard,N. Delahaye,R. Lebtahi,L. Sarda, Y. Petegnief, D. Le Guludec, M. Faraggi. Bichat Hospital, Paris° France.

Dorsal adquisition (DA) in male often generates inferior attenu_ ation (IA) disminishing specificity. Ventral adquisition (VA) dismi nish I A , patient's motion (PM) and It has been proposed as the best choise in male instead of DA. Objectives: Evaluate • I) the capacity of V A to disminish IA. II) If DA can be replaced by VA. III) Follow up (FU) in P consider as normal after D+V. Material: 82 P with diagnostic problem (Dxp) by probably IA in DA. Age X 57 (38-85) no prior MI, no ischemia during stress. TC 99m MIBI (11 mci) DA and then VA. Methods: 1) PM (_> 2 pixels) 2) Subjec tive: a) segmental uptake D and V. b) Severity score (SS) 0-3 (Normal to severe uptake reduction (UR)). 3) Quantitative: h£ mogeneity in global and segmentary image and wall ratio (WR). Results: 1) PM p=ns 2)Subjective % of segments (S)with UR (D/V) mid-inf 90/29 (*); bas-inf 94/32 (*); ap-lat 0/40(*); mid-ant 0/27 (*); apex 2/15 (,) - SS (D/V): ap-lat 246/208 (*); mid-ant 246/224 (.); mid-inf 161/221 (*); bas-inf 133/218(*) - 80% midinf and 86% bas- inf S improved uptake in VA. 3). Quantitative • % general uptake: D 80 + 17. V 80 + 14. % S uptake : D/V (+ %SD): ant 82(7)/77(9); sep 77(10)/79(10); inf 66(10)/72(8); lat 91 (5)/91 (5); apex 89(7)/85(8) W R inf/lat. D:..80 V: .93 (p<0•027) sep-lat: D .84 V: .88 (p=ns) 4) FU no cardiac events 8th month• Conclutions: 1) there were no differences in PM 2) V A dis minshed IA improving homogeneity in inf wall but caused new artifacts in other S with Dxp. 3) The findings suggest that D+V in this group of P is reliable. (*) p<0.0001 (°) p<0.01

The association of non uniform attenuation correction (AC) using scanning line source and depth-dependent Resolution Recovery (RR) in thallium 201 myocardial studies was compared to a single filtered back projection (FBP) in cardiac phantoms, normal subjects and patients (pts). 22 controls with prevalence of CAD < 5% and 21 pts with right or Cx coronary artery disease (7 inferior myocardial infarction) were included 2 weeks before coronary angiography. In phantom studies, AC + RR enhanced the ratio myocardium/LV cavity activity of 25% and improved the estimation of the inferior and/or lateral defect size of 50%. Conversely, in human subjects, AC + RR induced a loss in diagnostic accuracy, probably due to an overestimation of the inferior wall uptake due to bowel activity. Moreover, 9 reverse redistributions in the anterior or apical walls occurred with AC + RR.

AC + RR FBP

FN inf wall 9 1

FP inf wall 3 5

Se 18% 90%

Sp 70% 50%

F =false; N = negative ; P = positive; Se = Sensitivity; S p = Specificity.

A scatter correction should improve the accuracy of AC+RR in minimizing the effects of bowel activity.

Journal of Nuclear Cardiology Volume 6, Number 1, Part 2

Abstracts Monday afternoon, April 19, 1999

$29

1 5.28

15.30

EVALUATION OF SIMULTANEOUS 2°tTI EMISSION AND 153Gd TRANSMISSION CARDIAC SPECT S.D.Heenan, D.L.Bailey, &Allen, J.A.E.Dutton, S.E.M.Clarke, G.J.R.Cook and M.N.Maisey. Department of Nuclear Medicine, Guy's & St Thomas' Hospitals, London. UK.

INITIAL VALIDATION OF MUSIC®, AN ATTENUATION CORRECTION METHOD D. Wyndaele, E. Van Steelandt, M. Heroes. B. Kmg, A.Z.H. Hart, Tienen, Belgium

We have previously shown that simultaneous SPECT acquisition of 2°1TIand 153Gdtransmissionscans (TS) with dual moving line sources (-1.5 GBq per source) on an ADAC Vantage produces very little (< 3%) downscattered photon contamination from 153Gd. The aim of this work has been to assess the impact of the simultaneous protocol on reconstructed images. Thirty three patients received ~74 MBq of 2°1TI at rest and had consecutive SPECT scans under identical conditions, except that in one study a simultaneous TS was acquired. Image quality was assessed by two blinded experts. Images were assessed in random order without knowledge of (i) whether a TS was acquired, or (ii) if attenuation correction (AC) had been applied. No scatter correction was applied. Images were scored on their acceptibility for diagnostic interpretation from 1 (poor) to 5 (excellent). The presence of the TS, but without AC led to a degradation in image quality from 3.1 (out of 5; mean of the 2 observers) to 2.7 which we attribute to the decrease in total acquired emission counts. AC improved image quality from 2.7 to 3.05. In conclusion, 2°1TI image quality is slightly degraded when a TS is acquired using a moving line source of 153Gd due to the decrease in emission count rate from the transmission spatial windowing, however, when used for AC the quality is restored to an acceptable level.

The purpose of this study was the evaluation of the contribution of MUSIC® in the diagnosis of coronary- artery' disease (CAD). This attenuation correction method being evaluated on a 3-headed gamma camera (multi-SPECT 3) is based on the reconstruction, of a densi .t.t.tymap obtained from an Americium-241 transmission image. The Americium source is a rod placed at the angle between 2 detectors, and is "seen" by 1 opposing offset fan-beam detector. Transmission and emission data are acquired simultaneously. Channel cross-talk from the Am-241 source into the T1-201 channel or from Tc-99m into Am-241 channel are corrected. Reconstruction is iterative (an analytical iterative pre-correction algorithm with 2 iterations), after re-sampling to account for the fan-beam geometry, of one of the detectors. 38 patients with a low likelihood of CAD were initially studied (32 with TI-201 and 6 with Tc-99m as tracer) in stress conditions (bicycle or pharmacological stress) as well as in rest. The attenuation corrected images were compared with the noncorrected images visually as well as semi-quantitatively. A slight alteration (less than 20%) of the tracer distribution was more frequently noticed in the apical region ("apical thinning" was observed in 17% of the patients) than in the inferior wall or in the anterior wall and the septum. CONCLUSION: In 2 out of 3 patients, the altenuation corrected study added to the diagnostic confidence Coy determining factors of attenuation). No false positive or false negative diagnoses of myocardial ischemia were made.

15.29

15.31

ATTENUATION CORRECTION (ATC) IMPROVES INFARCT SIZE ASSESSMENT WITH TI-201 SPECT IMAGING S. Livschitz, J. Baron, I. Novikov, I. Moalem, E. Kaplinsky, P. Chouraqui. Heart Institute, Sheba Medical Center, Tel Hashomer, Israel.

ATTENUATION SMEAR: A PARADOXICAL INCREASE IN COUNTS DUE TO ATTENUATION ARTIFACT AND FILTERED BACK PROJECTION.

An ATC method using simultaneous transmissionemission acquisition was used to study the influence of attenuation artifacts on infarct size assessment by rest TI-201 SPECT imaging in 30 patients. Infarct size was assessed by semiquantitative analysis of uncorrected and corrected SPECT images and correlated with LVEF assessed by MUGA. Results (mean+SD): LVEF was .44 _+. 15, range=. 17.62. The number of abnormal segments (VAS) was lower with ATC (6+5) than without ATC (8+5, p=.005) and the summed visual score (SVS) of these segments was higher without ATC (26+16) than with ATC (20+17,p=.01). A stronger correlation was found after ATC than before ATC between SVS and LVEF (r2=.83 vs r2=.67, respectively) as well as between VAS and LVEF (r2= .80 vs r2= .65, respectively). Thus, attenuation correction may improve infarct size assessment by rest TI-201 SPECT imaging.

C. L. Hansen, R. Sangrigoli, E. Nkadi, M. Kramer. Temple University Hospital, Philadelphia, P A We have noted an artifactual "smear" of activity on the apical septal side of the ventricle in patients with significant breast attenuation (BA). W e postulated that this artifact was due to a combination of attenuation and the use of filtered back projection (FBP) for reconstruction. A cardiac phantom was filled and imaged with and without simulated BA. The phantom was reconstructed using F B P and with an iterative maximum likelihood (ML) reconstruction algorithm. Reconstructed images were compared. Using FBP in the B A phantom resulted in a "smear" of activity extending from the apex of the ventricle reproducing the artifact we had noticed on patient images. When the phantom without B A was reconstructed using FBP, no smear artifact was present. Reconstructing the phantom with B A using M L markedly reduced, but did not entirely eliminate, the smear artifact. W e conclude that the attenuation smear artifact is caused by a combination of the effects of attenuation with the use of FBP for reconstruction and represents a side effect that the violation of the underlying assumptions of FBP, caused by attenuation, has on the reconstructed image.

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M O N D A Y P M A P R I L 19

Abstracts

Journal of Nuclear Cardiology

Monday afternoon, April 19, 1999

January/February 1999, Part 2

15.32

15.34

INFERIOR WALL ARTIFACTS IN PAKISTANIS: THE CENTRAL OBESITY EFFECT Nishtar. S, Khan. I. S, Shahab. S, Mattu. M. A. Pakistan Institute of Medical Sciences, Islamabad Pakistan.

CORRELATION OF GATED SPECT IMAGING WITH TWO-DIMENSIONAL ECHOCARDIOGRAPHY IN REGIONAL AND GLOBAL LEFT VENTRICULAR WALL MOTION ASSESSMENT H Brandspiegel, J Burke, A Chevres. Lankenau Hospital, Wynnewood, PA This study compares 99m-Tc-tetrofosmin gated single photon emission computed tomography (gated SPECT) and two-dimensional echocardiography (2DE) in the assessment of regional and global left ventricular (LV) wall motion (WM). Methods: 204 consecutive patients who had both gated SPECT imaging and 2DE were evaluated. Regional and global LV WM was assessed with a 12 segment gated SPECT and a 16 segment 2DE method. We used a semiquantitative visual scoring scale for WM. Results: We found agreement between the two methods in 0.92 of the patients (kappa=0.79) in the assessment of regional WM abnormalities. McNemar comparison shows a p value of 0.049. In the assessment of global LV function, agreement was noted in 0.87. The 26 patients in whom disagreement was noted differed by only one predefined subgroup. Conclusion: Our data demonstrate that 99m-Tc-tetrofosmin gated SPECT imaging provides similar assessment of both regional and global LV function when compared to 2DE.

Objectives: To detemame the diagnostic accuracy of SPECT scanning in the diagnosis of Coronary Artery disease using Coronary Angiography as a gold standard. Methods: 49 pati~ts having tmdergone stress ThaUium-201 or Tc 99m labelled Sestamibi SPECT and coronary angiography within six months were enrolled. Coronary luminal stenosis was compared with imaging data in corresponding myocardial perfusion beds. The Left Anterior Descending artery corresponded to the Anterior wall and the Septum, the Circumflex Coronary to the Lateral wall and the Right coronary to the Inferior wall. Results: The patient population was predominantly male (81.1%%), with a mean age of 51.1 +/-10.9. SPECT scanning, in the definition of I_~ Anterior Descending Artery lesions showed a sensitivity of 97.66%, a specificity of 100% and a positive predictive value of 100%. In the definition of the Circulrrflex Coronary Artery lesions it showed a sensitivity of 94%, a specificity of 100% and a positive predictive value of 100% and in the definition of Right Coronary artery lesions, a sensitivity of 100% but a specificityof 48% and positive predictive value of 65% only. Conclusion: Central Obesity in Pakistanis with Corollary Artery Disease may be responsible for the poor predictive value of SPECT scanning in the detection of Right Coronary Artery Disease.

15.33 TI-201 SPECT BE'lEER PREDICTS PROGNOSIS THAN DOBUTAMINE ECHOCARDIOGRAPHY V. Bouiet, J. Lipiecki, D. Mestas, E. Albuisson, F. Philippot, A. Amonchot, O. de Tauriac, N. Dural, B. Citron, J. Ponsonnaille, J. Maublant. University Hospital, Clermont-Ferrand, France Defect size (DS), left ventdcular ejection fraction (LVEF) and wall motion (WM) after a first myocardial infarction (Mt) were prospectively compared with clinical outcome in 67 patients (pts). DS was assessed by TI-201 rest SPECT, LVEF and WM by dobutamine echocardiography (DE), both performed before coronary angioptasty. Outcome, based on clinical examination, stress test and gated blood pool, was evaluated 22+_12 months later. 10% of the pts presented at least one major clinical event. DS was the most predictive factor for occurrence of major clinical event (35+18% in pts with event vs 13+13% in the others, p<0.0001), of functional status (Duke score of 42_+15 if DS<22% vs 34+_17 otherwise, p<0.05) and of duration of stress test (570+220 s if DS<22% vs 405+200 s otherwise, p<0.02). Late improvement in LVEF was better predicted by DE (ALVEF>5% had WM score of 1.45_+0.2 vs 1.64+0.4 otherwise, p<0.05). In conclusion, cardiac events and functional status in MI are better predicted by TI-201 SPECT than DE.

15.35 Q U A N T I T A T I V E G A T E D S P E C T F I N D I N G S IN T H E SEGMENTS WITH NORMAL PERFUSION AND N O R M A L W A L L M O T I O N ON U C G

M.Konno, I.Adachi, K.Morita, MB.Imran, T.Mochizuki, T.Kohya, N.Kubo, Y.Ito, A.Kitabatake and N.Tamaki. Hokkaido University

School of Medicine, Sapporo, Japan.

Quantitative Gated SPECT (QGS) has been applied for evaluation of global and regional left ventricular (LV) function. In order to compare QGS findings with UCG findings, we evaluated the segmental wall motion (WM) on 3D surface display of QGS and UCG WM evaluated within two weeks. Resting gated SPECT was performed in 30 patients with chronic coronary artery disease (CAD), one hour after injection of 600MBq of Tc-99m MIBI. LV was divided into 9 segments (total 270 segments) and each segmental WM was assessed by 6 independent nuclear physicians to score 5 points scale from 0 (normal) to 4 (dyskinesia). Finally the average scores for each segment were used for comparison of the WM on QGS with that on UCG. There was a poor correlation between QGS and UCG WM scores (r=-0.35 p~0.01). QGS showed abnormal WM in 21.3% (33/155) of normally perfused segments with normal WM on UCG. Such abnormality was most often observed in -apical (5/11 ; 45.5%) and septal (15/29 ; 51.7%) regions compared to other regions; anterior (7/43 ; 16.3%), inferior (4/30 ; 13.3%), lateral (2/42 ; 4.8%) region. The wall motion score in septal region on QGS was higher ( 2 . 0 2 0.73) than any other segment (average 1.54+0.40) (P=0.014). We conclude that WM analysis on septum and apex should be carefully evaluated for WM on QGS. Further study is needed to determine whether QGS may overestimate or US may underestimate WM abnormalities in these regions.

Journal of Nuclear Cardiology Volume 6, Number 1, Part 2

Abstracts Monday afternoon, April 19, 1999

$31

15.36

15.38

COMPARISON OF DOBUTAMINE STRESS ECHOCARDIOGRAPHY AND 2°1THALLIUM SPECT IN THE EVALUATION OF THE EXTENT OF CORONARY ARTERY DISEASE AFTER MYOCARDIAL INFARCTION

GOOD AGREEMENT BETWEEN LEFT VENTRICULAR EJECTION FRACTION AND WALL MOTION SCORE IN GATED SPECT VERSUS CONTRAST ANGIOGRAPHY.

Abdou Elhendy, Jeroen J Bax, Marcel L Geleijnse, Roelf Valkema, Peter R Nierop, Eric Krenning, Jos Roelandt. Thoraxcenter and the Department of Nuclear Medicine, Rotterdam, The Netherlands

Objectives. To compare file accuracy of dobutamine-atropine stress

D.E. Atsma, C. Croon, P. Dibbets, L.H.B. Baur, E.E. van der Wall, E.K.J. Pauwels. Leiden University Medical Center, The Netherlands

echocardiography (DSE) and 201 thallium (T1) for the diagnosis and localization of coronary artery disease (CAD) after myocardial infarction. Methods. DSE in conjunction with stress-reinjection TI SPECT was performed for evaluation of myocardial ischemia in 90 patients 6.1 + 5.5 years after acute myocardial infarction. Ischemia w a s defined as new or worsening wall motion abnormalities by DSE and reversible perfusion defects by T1. Results. Significant CAD (_>50 % luminal diameter stenosis) was detected in 73 (81%) patients. The sensitivity, specificity and accuracy of remote ischemia for the diagnosis of remote CAD (53 patients) were 79%, 85% and 81% for DSE and 75%, 78% and 76% for T1 respectively. Sensitivity, specificity and accuracy of peri-infarction ischemia for the diagnosis of infarct related artery stenosis (70 patients) were 77 %, 85 % and 79 % for DSE and 73 %, 85% and 76% for T1 respectively (p = NS vs DSE). The agreement o n the diagnosis of peri-infarction and remote ischemia was 70% (Kappa = 0.37) and 80% (Kappa = 0.59 ) respectively. Conclusion. DSE and 201 T1 SPECT have comparable accuracy for the diagnosis of infarct related and remote CAD after myocardial infarction. The agreement between both methods is higher for the diagnosis of remote than peri-infarction ischemia.

Left ventricular ejection fraction (LVEF) is a major prognostic parameter in patients (pts) with coronary artery disease. The new ECG-gated single photon emission computer tomography (gated-SPECT) technique allows measurement of LVEF in addition to myocardial perfusion. We compared the LVEF and ventricular wall motion obtained using gated-SPECT with traditional contrast ventriculography in 69 pts after injection of 500 MBq 99mTc-tetrofosmin. LVEF determined using gatedSPECT correlated well with contrast ventriculograpy (y = 0.96x + 1.3, rA2=.86, p<0.001), with no systematic differences between the two methods. Wall motion, scored on a 4-point scale, was identical in 88% of 486 segments analyzed. We conclude that gated-SPECT using 99mTctetrofosmin is a valuable new tool to reliably determine LVEF and wall motion, offering the simultaneous measurement of myocardial perfusion and tEnction.

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15.39

A C O M P A R I S O N OF G A T E D R E S T Tc-99M SESTAMIBI SCINTIGRAPHY AND ECHOC A R D I O G R A P H Y 1N THE A S S E S S M E N T OF ACUTE CHEST P A I N J. Swinbum, P. Soman, U.Raval, A, Lahiri, R. Senior. Northwick Park Hospital, Harrow. U K

ARE LV EJECTION FRACTION (EF), END DIASTOLIC (EDV) AND END SYSTOLIC VOLUMES (ESV) MEASURED WITH REST TL-201 GATED SPECT ACCURATE ? D. Daou, B.O. Helal, P. Colin, T. Fourme, S. Dinanian, I. Pointurier, L. Saidi, A. Benada, A. Prigent, M. Slama. Antoine Beclere Hospital, Clamart, France. Coupling of myocardial perfusion and function studies is of much clinical and economical interest. We studied in 19 pts the value of rest TI-201 gated SPECT for the calculation of LV-EF, EDV and ESV using each of 2 commercially available 3D softwares (QGS, Multidim), to measures provided by equilibrium ECG-gated planar (LVEF) and SPECT RNA (LVEDV, LVESV - 60% threshold method). Measures done with radiological angiography (Rx) were also compared. LVEF calculated with Multidim, QGS and Rx correlated well to planar RNA (p<0.02) with similar slopes=0.9 and r=0.7. Mean values and variance of each of the 3 methods were similar (NS). The overall LV-EDV and ESV calculated with Multidim, QGS and Rx correlated well to those of SPECT RNA (p<0.0001) with respectively r=0.7; 0.7 and 0.8. The volumes calculated with QGS were lower than with the other 3 methods imposing the use of a correction factor (p<0.001) while the variance with Multidim was higher (p<0.05) making this method less precise than QGS. Thus, QGS, Multidim and Rx provide similar accuracy for LVEF but Multidim is less precise for LV volumes.

To determine the usefulness of rest technetium-99m sestamibi SPECT (MIBI) for the assessment o f acute chest pain, 76 patients with chest pain were imaged and also underwent 2-dimensional echocardiography (2DE) within 6 hours o f presentation. Gated data was incorporated if an abnormality was seen on perfusion scans. The number o f patients with abnormal MIBI after gating and abnormal 2DE scans was 45 and 46 respectively. The concordance between the two techniques for the detection of abnormality was 86% (kappa=0.7), and for identification o f abnormality in a specific vascular territory was 71% (kappa=0.5). O f the 58 MIBI scans which required gating interpretation, diagnostic certainty was altered in 16 (28%). Thus there was a good concordance between gated resting MIBI and 2DE.

M O N D A

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Abstracts Monday afternoon, April 19, 1999

Journal of Nuclear Cardiology January/February 1999, Part 2

15.40 M O N D A Y P M A P R I L 19

15.42

NATRIURETIC PEPTIDES ARE INSENSITIVE TO DETECT MILD ANTHRACYCLINE-INDUCED LEFT VENTRICULAR DYSFUNCTION T.Nousiainen, E.Jantunen, E.Vanninen, J.Remes, O.Vuolteenaho, J.Hartikainen. Kuopio University Hospital, Kuopio, Finland

QUANTITATIVE LEFF VENTRICULAR VOLUME (LVV) AND EJECTION FRACTION (LVEF) BY 3D CONTRAST HARMONIC COLOR DOPPLER LEFF VENTRICULAR COMPARED TO RADIONUCLIDE VENTRICULOGRAPHY (RNA). G. Villa, G.P. Bezante, A. Rahimi Mansour, X. Chen, K.Q. Schwarz. Dept. Internal Medicine, Univ. of Genoa, Genoa (Italy); Univ. of Rochester, Rochester, NY (USA).

The aim o f the study was to evaluate whether measurements of atrial natriuretic peptide (ANP), N-terminal pro-ANP, and brain natriuretic peptide are sensitive to detect anthracycline-induced LV dysfunction. RVG was used as the reference method. Twenty-eight adult patients were followed by serial measurements o f LVEF and natriuretic peptides up to a cumulative doxorubicin dose o f 400-500 mg/m 2. LVEF decreased from 58.0+1.3 % (mean_+_+SEM)to 49.6_+1.7 % (p<0.001). All natriuretic peptide levels increased concomitanly significantly (p<0.05). However, the decrease in LVEF started already at the 200 mg/m 2 dose level, while natriuretic peptide levels started to increase not before 400 mg/m 2. In conclusion, natriuretic peptides are insensitive to detect mild impairment o f LV function, but they appear to be useful in detection more advanced anthracycline-induced LV dysfunction.

Accurate and reproducible quantification of LVV and LVEF is critically important in the practice of clinical cardiology. RNA is considered as the gold standard for measuring these parameters because it is accurate, nonoperator-dependent and reproducible. Echo LVV and LVEF measurements are subject to variability in image acquisition, interpretation and to the limitations of 2D v e r s u s 3D imaging. We compared LVV and LVEF determined by RNA to three different echo imaging techniques in 35 patients: harmonic 2D-echo (H2D), contrast enhanced harmonic 2D (CH2D) and harmonic color Doppler contrast left ventriculography (CHCD). The RNA LVEF range was 9 to 70% and the RNA LVV ranged from 40.8 to 257 ml and 16.6 to 233 ml at ED and ES, respectively. All three echo techniques showed excellent correlation with the RNA LVEF (R ~ >0.96), but the the CH2D method had the lowest RMS residuals. The ED and ES LVV by CHCD correlated better with the corresponding RNA volumes than did either H2D or CH2D, which tended to overestimate LVV.

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15.43

AUTOMATIC MEASUREMENT OF LEFT VENTRICULAR EJECTION FRACTION (LVEF) BY GATED TI-201 SPECT: VALIDATION VS 2D-ECHOCARDIOGRAPHY C. Bacher-Stier, S. Mueller, S. Schwarzacher, S. Strolz, M. Wenger, H. Erler, E. Donnemiller, R. Moncayoand G. Riccahona. Dpt. of Nuclear Medicine, University Hospital hmsbruck, Austria.

COMPARISON OF LEFf VENTRICULAR ~ I O N BY GATED MYOCARDIAL PERFUSION SCINTIGRAPHY WITH IMA6~ INVERSION TECHNIQUE WITH EQUILIBRIUM RADIONUCLIDE ANGIOGRAPHY (RNG). G. Rubini, V. Todino, A. Cuocolo, A. D'Addabbo Dept Nuclear Medicine-University of Bari Italy

Simultaneous assessment of myocardial perfusion and function with ECGgated acquisition after a single tracer injection is desirable. The currenl stud}' was aimed at the validation of Gated Spect (GS) with T1-201 agams! 2D-echocardiography (echo), which was not shm~n belbre. After injection of 111 MBq TI-20 [ at peak bicycle exercise (n=58), or after pharmacologic stress (n=12), GS was performed 15 rain (post-stress) and 2 hrs p.i. 0"est) on a double head camera, follov,ed by LVEF measurement with 2D-echo (Acuson Sequoia C256, 13 Mhz). An automatic algoritlun ~as used Ibr processing ofGS (Gerrnano et.al 1995). Results:

This study was designed to cc~pare the assessment of left ventricular function by ECG-gated 99m~c-MIBI LAD 45° images (Inv G) and image inversion technique with blood pool RNG. i00 Pts with suspected or documented coronary disease were studied by S/R MIBI SPET with a gated LAD 45° images on the resting study day and RNG within three days. The LVEF calculation was alaways a count based method. An excellent correlation (p<0,001) with no significant differences was found, by blandAltman graphic test, between Inv G and RNA LVEF. In 55 Pts without previous myocardial infarction Inv G LVEF was 59,8+5, i, while in pts with previous MI was 41,9_+13,7 (p<0,001). Also in 21 pts with RNA LVEF <40% Inv G provides ~ a b l e values. The intra and interobserver reproducibility was good (p<0,001 ).The fully autcmated myocardial perfusion Inv G images technique with a count based to evaluate LVEF permit to obtain similar results of RNA and can be associated with S/R myocardial perfusion scintigraphy.

flIl~!~n=70):L LVEF %_+ SD (Range) Correlation vs echo

LVEF % + SD (Range)

GS post-stress 57.7+13.4

GS Rest 54.5_+13.4

EchoRest 53.4_+12.7

.(.21186) .............................. .(1.828.2). .................. .(..!.8788). .......

R=0.71

11--0.81

(p<0001)

(p<0.001)

35.7 + 11.3 (18-

35.1 + 9.3 (18-48)

9,) ......................................

Correlation vs echo

R= 0.90 (p< 0.001 )

Conclusion: GS ,Mth TI-201 is a reliable tool for detection of pts with compromised left ventricular function, improving diagnosis and prognostic stratification of cardiac pts.

Journal of Nuclear Cardiology Volume 6, N u m b e r 1, Part 2

Abstracts Monday afternoon, April 19, 1999

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15.46

LVEF VIA 3-D AUTOMATIC QUANTIFICATION GATED MYOCARDIAL PERFUSlON SPECT COMPARES FAVORABLY WITH CONTRAST LEFT VENTRICULOGRAM

EVALUATION OF LEFT VENTRICULAR F U N C T I O N AND WALL MOTION WITH GATED SPECT MYOCARDIAL PERFUSION STUDY AND COMPARISON WITH ECHOCARDIOGRAPHY D.C. Yang, K. Kulkarni, J. Kalani, M. Das, M. Makan NY Methodist Hospital, New York, U.S.A. PURPOSE: To determine the reliability and validity of new Gated SPECT (GS) procedure we compared LV ejection fraction (LVEF) and wall motion abnormalities derived from GS and echocardiography (ECHO). METHOD: We have performed 256 studies from July 97 to Feb. 98. We reviewed 50 patients (25M and 25F, age range 42 to 86 years, mean 61± 13) in whom ECHO was performed within a period of± 15 days of the GS study. GS study was performed 30 to 60 minutes after IV injection of 555 Mbq of Tc-99m Tetrofosmin or Sestamibi using an 8 frame/cycle gating of the stress study. An automated myocardial GS processing software developed by Cedars-Sinai Medical Center, UCLA was used. Parameters evaluated were end diastolic volume (EDV), end systolic volume (ESV), LVEF and wall motion abnormalities. RESULTS: LVEF calculated by GS was 62± 16 (range 2282) and by ECHO was 63.5± 9.9 (range 25-75). Good correlation between GS and ECHO were found for LVEF (r=0.7, p<0.006). There is significant correlation between ECHO and GS in the evaluation of wall motion abnormalities.

Robert D. Tan-Gatue, Edmundo V Villacorta, Ma. Milagros D Uy, Flordaliz E. Mendoza and Carlo D Santos-Ocampo, Department of Nuclear Medicine, Makati Medical Center, Metro Manila, Philippines Background: A novel method of calculating LVEF using automatic 3-dimensional edgedetection in conjunction with Tc-99m tetrofosmin perfusion scintigraphy has recently been developed. However, its accuracy has been questioned in scans with perfusion defects This study compares the LVEF values ~tained during Tc-99m tetrofosmin gated SPECT perfusion scintigraphy using a 3-dimensional automatic summation method with LVEF measurements derived from contrast left ventriculegram Methods: Twenty subjects (M=17, F=3) with abnormal myocardial perfusion defects were enrolled between September 1997 to January 1998 All these subjects underwent Tc99m letrofosmin SPECT imaging and cardiac catheterization within a 4 month period. Calculation of the LVEF was generated automatically using the Simpson's rule of summation of elliptical slices on paired vertical and horizontal long axis tomograms These results were compared with data from cardiac catheterization and contrast left ventriculegraphy Statistical analysis was performed using linear regression and paired t tests. Results: Linear regression ~ 1 analysis demonstrated Pearson 70 II correlation coefficients of 0 75 ~ so for both nuclear and angiegraphic E ~ methods, Paired t tests likewise revealed gated SPECT ejection ~ :j fractions comparable to ~- 2o 1 angiegraphic values 8 ~0

0g 0

20

40

~0

80

Gated $PECT LVEF (%)

Conclusion: The use of quanlitatk,e 3-0 automatically generaled gated SPECT ejection fractions, even in scans wilh peffusion defects, correlates well with contrasl angiegraphic values

15.45

15.47

FRACTION AND WALL REST AND DURING LOW-DOSE DOBUTAMINE IN PATIENTS WITH SEVERE LV DYSFUNCTION. COMPARISON BETWEEN GATED-SPECT AND ECHOCARDIOGRAPHY.

SIMULTANEOUS EVALUATION OF MYOCARDIAL ISCHEMIA AND REGIONAL WALL M(3TION WITH ATP INFUSION BY FAST QUANTITATIVE GATED SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY (FAST QGS).

FI Frascarelli, *G. Marcueci, M. Leoncini, *M. Silvestri, L. Bini, A. Traini, D. Mondanelli, *A. Arena, *C. De Gaudio, L. Bardazzi, A. Petrella, *A. Mennuti. Division of Cardiology and *Nuclear Medicine, Prato Hospital, Italy,

S.Tange,Y.Tuchio,G.Ui,IN.Nogiku,K.Yoshino,T.Kato,H.Kumaku ra,Y.Takayama,S.Ichikawa.Cardiovascular hospital of central Japan, S e t a - g u n , Japan.

Gated Tc-99m sestamibi SPECT (G-SPECT) imaging allows automated computer calculation of LV ejection fraction (EF) and the assessment of wall motion (WM) at rest and during low-dose dobutamine (LDD) infusion. We compared G-SPECT with echocardiography (ECHO) in 25 patients (pts) with CAD and severe left ventricular dysfunction. WM was scored from 1 (normal) to 4 (dyskinetic) using a 16-segment model for both ECHO and GSPECT. Left ventricle was divided into three vascular territories. RESULTS: 47 asynergy vascular territories were considered. rest-EF LDD-EF rest-WM LDD-WM G-SPECT 30÷12 35+14 § 2.30:k0.5 2.0i0.6" ECHO 32:t:10 40m10/, 2.49±0.4 2.1:i:0.5' §--p<0.001 and ~'=p<0.000001 vs rest-EF;*-p<0.000001 vs restWM.There were no significant differences between the two methods for rest-EF, whereas LDD-EF (p<0.05), rest-WM (p<0.01) and LDD-WM (p<0.05) were lower in G-SPECT; good correlations (Spearman's p) between ECHO and G-SPECT were found for restEF (9=0.77; p<0.001), LDD-EF (9-0.80, p<0.0001), rest-WM (9=0.64; p<0.00001) and LDD-WM (9=0.67; p<0.000001). Thus, in pts with poor LV function, the analysis of EF and WM at rest and during LDD using G-SPECT is comparable to the results of ECHO.

It is n o w possible to evaluate regional wall motion a n d perfusion simultaneously by QGS u s i n g T c - 9 9 m myocardial perfusion agent, in w h i c h fast scan c a n be available by h i g h e n e r g y of Tc-99m. We prospectively studied the a c c u r a c y of regional wall motion abnormality(WMA) a n d myocardial perfusion defect (PD) u s i n g fast QGS before a n d after ATP infusion b y comparing with the result of coronary a n g i o g r a m . T h e fast OGS with Tc-99m tetrofosmin were performed to 48 consecutive a n g i n a l patients (age 68.7+-8.2 ) at rest a n d d u r i n g ATP infusion, followed b y coronary a n g i o g r a p h y w i t h i n a w e e k . T h e fast QGS with ATP infusion could be completed w i t h i n 15rain. Sensitivity a n d specificity of WMA by the fast QGS with ATP infusion w e r e 57% a n d 90% for detecting significant coronary stenosis (>75%) d e t e r m i n e d by coronary a n g i o g r a m , while those of PD were 95% a n d 90%, respectively; WMA s h o w e d severe coronary stenosis(>90%). The results s u g g e s t that WMA in the fast QGS with ATP infusion be usuful to detect myocardial ischemia, indicating severe coronary stenosis.

ANALYSIS OF MOTION AT

EJECTION

M O N D A Y P M A P R I L 19

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Abstracts Monday afternoon, APril 19, 1999

15.48 M O N D A Y P M A P R I L 19

ESTIMATION OF LEFT V E N T R I C U L A R W A L L M O T I O N WITH AUTOMATIC QGS PROGRAM BY TCTETROFOSMIN COMPARISON WITH LEFT VETRICULOGRAPHY

T. Tanaka, K. Miyao, T. Tokura,, A. Matso, H. Fujita, N. Inoue, T. Kuriyama, M. Kitamura. Division of Cardiology, Kyoto Second Red Cross Hospital,Kyoto,Japan We estimated the availability ofteft ventricular wall motion (LVWM) with automatic quantitative gated SPECT program (QGS) by 99mTctetrofosmin (TF) comparison with left ventfieulography (LVG). Methods: In 116 various cardiac patients, gated imaging were performed by TF592Mbq within 7 days of cardiac catheterization. LVWM in both QGS(3D image) and LVG were scored from the RAO 30* (5 segments) and LAO 50* (2 segments) views. We estimated the score of LVWM from 6 steps.We followed up the patients for any cardiac events. Results: In all 545 segments, the concordance rate with the score in one segment was 61%. The concordance rate with the score including over and under by one score was 86%. Concerning cardiac events, there were no reinfarction ,but cardiac death in 2patients, acute congestive heart failure(CHF) in 6 patients, unstable angina in 20, and angioplasty in 31. In these eve.nts, cardiac death occured in more than 18scores of the total wall motion score (TWS) ofQGS (p<0.0001),16scores of LVG(p<0.01) and 22scores of total defect score(TDS)+TWS(p<0.01) and CHF occured in more than 12 scores of TWS of QGS(p<0.05),12scores of LVG(p<0.01), and 16 scores of TDS+TWS (p<0.05). Conclusions: It is suggested that the estimation of left ventficular wail motion with QGS program with 99mTc-tetrofosmin is a useful, available and noninvasive method for the evaluation of clinical course in patients with cardiac diseases.

15.49 I N T E G R A T I O N O F D I F F E R E N T CARDIOLOGICAL IMAGING TECHNIQUES (ECHOCARDIOGRAPHY, C O R O N A R Y A N G I O G R A P H Y A N D SPECT) IN A POLAR M A P D I S P L A Y

Z. Koszegi, T. SzuL L. Balkay, L. Galuska, T. Fulop, L. Voith, I. Edes., University Medical School of Debrecen, Hungary Access-based software was developed to register the results of different cardiological investigations in 16 left ventricular segments in a polar map display in order to compare the anatomical and functional data. Ten patients ~4th previous myocardial infarction were selected (mean age: 48 years, EF: 36.1+7.2%). They had 14 totally or subtotally occluded coronary. branches. As a test the power of the mentally generated polar map of coronary angiography and echocardiography, the overlap between the occlusion-associated regions derived by angiography and the corresponding defects on MIBI SPECT, and also the echocardiographic segmental wall motion scores were evaluated. The distribution of the total of 160 segments ~Sth rest perfusion defects on MI]3I SPECT and the wall motion abnormalities detected by, echocardiogaphy gave positive and negative predictive values of coronary occlusion of 0.94 and 0.81 against SPECT, and 0.82 and 0.76 against echocardiography, respectively. Furthermore the relative MIBI actix4ties of the indi~idual segments correlated significantly ~4th the wall motion scores (r=-0.87). It is concluded that the direct comparison of tomographic imaging and echocardiography with the angiogram on the polar map display in order to measure the functional consequences of coronary artery- disease may help to judge the clinical significance of an indi~4dual corona~ ~lesion.

Journal of Nuclear Cardiology January/February 1999, Part 2

15.50 DETERMINATION OF LEFT VENTRICULARVOLUME AND EJECTION FRACTION BY G-SPECT MYOCARDIAL PERFUSION SCINTIGRAPHY. A COMPARISON WITH QUANTITATIVE 3D-ECHOCARDIOGRAPHY.

C.Cittanti, D.Mele, P.Colamussi, M.Giganti, A.Dafermou, A.Ciprian, P.Alboni, A.Piffanelli. University of Ferrara, Itals~. Background: Left ventricular (LV) volume and ejection fraction EF) are important prognostic factors in ischemic heart disease. I9mTc-sestamibi gated-SPECT myocardial perfusion scintigraphy (GSPECT) has been recently introduced for assessment of LV volumes and EF but little quantitative information is available in a clinical setting. The aim of this study was to compare quantitative estimates of LV end-diastolic and end-systolic volumes (EDV, ESV) and EF obtained by this nuclear technique with values obtained by 3Dechoeardiography (3D-Echo). Methods: Eight consecutive patients (age 61+9 years, 7 males and 1 female), affected by ischemie heal~ disease with dilated or distorted LVs, underwent both nuclear and 3Decho studies within 24h at rest. The G-SPECT acquisition was performed by using a 90° double-detector camera (8 frames/cardiac cycle); an automated commercially available software was used to segment the LV and calculate its volumes. The 3D-Echo study was performed by using a rotational apical approach for image acquisition, manual tracing of endocardial borders and a cubic spline algorithm for reconstruction of cavity volume. Results: G-SPECT scintigraphy provided values that correlated and agreed well with data from 3D-Echo for EDV (y=0.Sx+20.2, r=0.99, SEE 10.7 ml, mean difference-2.1_+14.7 ml), for ESV (y=0.7x+21.6, r=0.99, SEE=9.3 ml, mean difference -0.8_+17.6 m]) and EF (y=0.8x+12, r=0.7, SEE=9.4%, mean difference -3.4+8.9%: all mean differences NS vs 0). Conclusions: In this initial group of unselected patients, this gated-SPECT technique was accurate in assessing LV volumes and EF compared to 3D-Echo. The software utilized for quantitation is completely automated and fast and therefore should facilitate evaluation of LV cavity size and function in routine clinical practice.

15.51 COMPARISON OF RADIONUCUDE ANGIOGRAPHY AND TWO DIMENSIONAL ECHOCARDIOGRAPHY WITH CONTRAST ANGIOGRAPHY IN DETECTION OF VENTRICULAR ANEURYSM C.Ginghini E.Apetrei, G.Jovin, B.Fotiade, I.Ene,l.Kulcsar. Institute of Cardiology "Prof.C.C.Iliescu",Bucharest, Romania. Purpose. The diagnostic ability of radionuclide angiography (RNA) and 2dimensional echocardiography (2D-ECHO) to assess left ventricular (LV) motion, geomelry and performance was compared with conlrast angiography (CA). Methods. We studied 37 consecutive palJents(pts.)with prior myocardial infarction and congeslive heart failure undergoing cardiac catheterisation (CC) for suspected LV aneurysm underwent gated equilibrium RNA and 2D-ECHO within 7 days of CC. Results. Both 2D-ECHO and RNA showed agreements with CA in assessing normal vs abnormal wall motion in anterior (91%, 90%), septal (87%, 79%) and lateral (78%, 79%) segments. Of 21 aneurysm confirmed at surgery 2D-ECHO detected 18 - with a sensitivity (sv} of 92% and specificity (sp) of 73%, RNA detected 16 (sv 88%, sp 91%) and CA detected all 21 aneurysm (sp 79%). Conclusions: RNA, 2D-ECHO and CA agree in evaluation of LV aneurysm, the 2D-ECHO and RNA are more useful than either alone for detection of LV aneurysm; the noninvasive techniques can be lead to a better selection of pts. for CC from pts. at high risk for invasive procedure and surgery.

Journal of Nuclear Cardiology Volume 6, Number 1, Part 2

Abstracts Monday afternoon, April 19, 1999

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15.54

EVALUATION OF ORDERED SUBSETS EXPECTATION MAXIMIZATION ( O S - E M ) O N N O R M A L M Y O C A R D I A L SPET P E R F U S I O N STUDIES. L Dierickx, C Vanhove, PR Franken. Free University of Brussels (VUB), Belgium.

ASSESSMENT OF LEFT VENTRICULAR FUNCTION BY THALLIUM-201 SPECT: USEFULNESS OF CAVITY-TOMYOCARDIUM COUNT RATIO. Th. Antonietti, Ch. Maunoury, S. Srbahoun, L. Barritault. H6pital Necker-Enfants Malades, Paris, France.

Iterative reconstruction algorithms have been proposed to improve image quality in SPET. With the introduction of OS-EM, iterative reconstruction can be accelerated within clinical acceptable times. The aim of this study was to compare filtered backprojection (FBP) with OS-EM. Ninety projections were acquired over 360 ° in 20 healthy volunteers (10 female, 10 male) using 925 MBq Tc99mtetrofosmine. FBP was done using a Butterworth filter (order 5) with a cut-off frequency of 0.57 Nyquist. A subset size of 6, together with 3 iterations, was used for OS-EM, followed by a Gaussian filter with a FWHM of 10mm. Evaluation was done by 2 observers using bullseye-quantificationdivided into 12 ROIs. Results were averaged and expressed as percentage of the maximum ROI. Significant differences between OS-EM and FBP were found in the apico-septal (91.6 vs 86.6), lateral (86.0 vs 91.21 and inferior ROIs (65.7 vs 69.3) in men, and in the anterior (78.7 vs 80.3) and mid-inferior ROIs (81.1 vs 83.2) in women. In conclusion, significant differences were found between OS-EM and FBP. Those differences were gender dependent. This necessitates the creation of an OS-EM normal database for men and women.

Equilibrium radionuclide angiography (ERNA) is the gold standard to assess left ventricular ejection fraction (LVEF). The aim of the study was to determine the value of left ventricular cavity-to-myocardium count ratio (LVCMR) obtained with T1-201 SPECT in reference to LVEF assessed by ERNA. Methods: The study group included 231 consecutive patients (170 male, 61 female), aged 59_+12 years, who underwent both T1-201 SPECT and ERNA at rest on the same day. The LVCMR was calculated from the mid-ventricular short axis slice, using two regions of interest. One ROI was placed in the center of left ventricular cavity (C) and another one in the myocardium with maximum uptake (Mmax): LVCMR=C/Mmax. Results: There was an excellent correlation between LVCMR and LVEF: r=0.83 (y=0.92x+6.90, P<0.0001). The mean calculated values _+ I SD were LVCMR=56+16% and LVEF=54_+14%. Conclusion: Easy to obtain from T1-201 SPECT, the LVCMR is a useful parameter to assess left ventricular function.

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15.55

A NEW PROGRAM FOR AUTOMATIC QUANTITATION OF MYOCARDIAL SPECT. D. Scellier, J.Y. Boire, J. Maublant. Centre J. Perrin, Clermont-Fd, France. Automatic quantitation of myocardial SPECT using a new approach based on mathematical morphology and fuzzy logic is proposed. The myocardium is first reoriented and positionned inside an ellipsoidal region of interest to mask extramyocardial areas. A thinning process allows to extract the skeleton of the organ, a one-pixel thick surface. Defects are filled according to a truncated bullet shape model. In order to restitute the overall watt thickness, even in case of defect or hypoactivity, a fuzzy logic approach is used. The degree of belonging to the myocardium is calculated for each pixel. The resulting myocardial image, which now contains the entire ventricular wall, is partitioned into 18 isovolumic sectors. Their activity is expressed relatively to the highest sectorial value and also in standard deviations by comparison with a normal data base available for TI-201, Tc-99m-sestamibi and Tc-99m-tetrofosmin. The intraand interobserver reproducibility, assessed in 14 patients (504 sectors), was always excellent (5% conformity).

IMPROVED DETECTION OF REVERSIBLE ISCHAEMIA BY Tc-99m SESTAMIBI COMPARED TO Tc-99m TETROFOSMIN SPECT IMAGING IN MILD TO MODERATE CORONARY ARTERY DISEASE P Soman, R Taillefer, GE Depuey, J Udelson, A Lahiri. Nortlmick Park Hospital, Harrow. UK To compare tile diagnostic accuracy of Tc-99m sestamibi (MIBI) and Tc-99m tctrofoslnin (TETRO), dipyridamole SPECT imaging with these 2 agents was performed in 72 patients (20 F, 52 M: age 59:t:12 years, -~t 77.3~15kg) without previous myocardial infarction and with recent arteriographic evidcnce of 50-90% stenosis in 1 or 2 epicardial corona U arteries. Six patients had <5% likelihood of CAD. The MIBI and TETRO studies were carried out in random order ~vithin 1 weck of each other, and reported blindly. The sensitivity for diagnosis of CAD of MIB1 and TETRO was 62% and 54% (p=0.07), and specificity 57% and 43% (p=l.0), respectively, Diagnostic accuracy for the detection of disease in individual coronary artew territories was similar. However, MIBI detected a significantly greater ,mmber of ischaemic segments (271 vs 21 |, p<0.01) and larger extent of perfusion defect (15±12% vs 12~11%, p<0.03). Therefore. MIBI seems to be superior to TETRO for the assessment of mild to moderate CAD by dipyridamole SPECT

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Abstracts M o n d a y a f t e r n o o n , A p r i l 19, 1 9 9 9

15.56

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PI~IMINARY CLINICAL STUDY IN MYOCARDIALI~OSION SPECT I~AGINGWITH 99=Tc-NOET:CO~PARISONWITH201T1 IMAGING Sheng Liu, Zeng tao Lin, Ning-yi J i a n g , e t a l . The Dept. of n u c l e a r medicine, Memorial H o s p i t a l , S u n - y a t Sen U n i v e r s i t y of Medical Sciences, Guangzhou 510120, P.R. China. 99mTc NOETis a promising, n e u t r a l l i p o p h i l i c myocardial p e r f a s i o n imaging a g e n t which has few c l i n i c a l study, so the r e a l c l i n i c a l v a l u e of 99mTc-NOET i s worthy of f u r t h e r study. SIJBJECTSanflI~I'HOD: CAD group:32 e a s e s ( 1 5 u n d e r w e n t c a r d i a c c a t h e t e r i z a t i o n ) . 23 c a s e s had both 99mTc~NOET and 201T1 matched imaigng, 9 c a s e s o n l y had 99mTe-NOET imagings. Control group:8 e a s e s ( 2 underwent c a r d i a c c a t h e t e r i z a t i o n ) , a l l underwent b o t h 99mTe NOETand 201T1 matched imaging. All s u b j e c t s were performed e x e r c i s e , s e r i a l d e l a y e d imagings. The d i f f e r e n c e s of t h e q u a l i t y of images, d i a g n o s t i c e f f i c i e n c y of CAD and d i s e a s e o f i n d i v i d u a l c o r o n a r y a r t e r y were compared in d e t a i l . RESI..1LTS:The q u a l i t y of 99mTc-NOET images was .lore o b v i o u s l y improved w i t h time, b u t poor in some images in 4 ~ 6 h o u r images. The agreement of m y o c a r d i a l segment r a d i o a e t i v i t y u p t a k e in e x e r c i s e and delayed (2 hour in 99mTc-NOET and 4 - 6 h o u r in 201T1) in 31 matched e a s e s was 269/279 (96.4%) , K = 0 . 8 9 ~ 0 . 0 5 9 , and 263/279 (94.2%),K=0.83 ± 0.035, r e s p e c t i v e l y , i n d i c a t i n g excellent concordance. In matched study, the s e n s i t i c i t y a n d specificity in d i a g n o s i n g CAD with 99mTc-NOET e x e r c i s e imaging was 91.3% and 95.4% r e s p e c t i v e l y . The o v e r a l l sensitivity and overall s p e c i f i c i t y in d e t e c t i n g d i s e a s e of i n d i v i d u a l a r t e r y was 81.2% and 96.7% r e s p e c t i v e l y , none had s i g n i f i c a n c e compared with 20IT1. In a l l 99mTc-NOET imaging, the s e n s i t i v i t y and s p e c i f i c i t y of d i a g n o s i n g CAD was 84.4% and 87.5% r e s p e c t i v e l y . CONLIJJSlONS: 99mTe-NOET was a new n e u t r a l m y o c a r d i a l p e r f u s i o n imaging agent, i t i t had r e d i s t r i b u t i o n f e a t u r e . The e f f i c i e n c y of d i a g n o s i s of CADwas s i m i l i a r to 201T1, and i t would be worthy of r o u t i n e c l i n i e a l a p p l i e a t i o n s u b s t i t u t i v e f o r 201T1.

15.57 FEASIBILITY OF SIMULTANEOUS STRESS SESTAMIBI/ REST "11 DUAL-ISOTOPE MYOCARDIAL PERFUSION SPECT IN THE DETECTION OF CORONARY ARTERY DISEASE AND THE ASSESSMENT OF MYOCARDIAL VIABILITY. M.Nakamura, K.Takeda, T.Ichihara, Nlsaka, T.Konishi, T.Nakano. Mie University, Tsu, Japan. This study assesses the feasibilRy of the simultaneous stress sestamibi/ rest TI dual-isotope myocardial perfusion SPECT. Ninety-two patients with known coronary artery disease had exercise with sestamibi injection follow ed by TI injection at rest 1 hour later, and dual-isotope SPECT w as performed. These results w ere compared to coronary angiographical findings. Crosstalk correction was performed using the method of Moore (1995) which contamination originated from lead X-rays produced in the collimator was subtracted in the TI window. The study was completed within 1.5 hours. The sensitivity and specificity of stress sestamibi/rest TI dual-isotope SPECT were 83% (951114) and 96% (156/162), respectively, when >75% coronary artery narrow ing was considered significant. The uptake of Tt in dual-isotope image correlated w ell with w all motion of Left ventriculography. The simultaneous stress sestamibi/rest TI dual-isotope imaging is feasible with the acceptable accuracy for the detection of coronary artery disease and the assessment of myocardial viability.

Journal of Nuclear Cardiology J a n u a r y / F e b r u a r y 1999, P a r t 2

15.58

DIAGNOSTIC ACCURACY OF STRESS TETROFOSMIN(TF) AND THALLIUM(TL) IMAGING IN SINGLE- VS. MULTI-VESSEL DISEASE. S.Tonafi, N.Hattori, H.Onaka, T.Kusumoto, H.Ando, LKonishi. Takatsuki Red-Cross Hospital, Takatsuki, Japan. Interpretation of the severity is sometimes difficult bv the radionuclide images. The purpose of this study whs to investi_oate the oaagnostie accuracy of TL and TF in evaluat']ng the severity of ischemic heart disease (IHD). Study population included 62 patients (M: 42, F: 20, age: 62.0 years) without myocardial infarction (single vessel disease= SVD:25, multi-vessel disease= MVD: 27). Stressreinjection TL study was performed for 45 cases, and stress-rest TF study was performed for 37 cases. Radionuclide images were interpreted to determine whether IHD were accurately detected in terms of number of involved vessels and their locations. Although both tracers detected the existence of IHD with similar sensitivity (TL vs. TF: 89 vs. 83%; p= n.s.) and specificity (50 vs. 57%; p= n.s.), SVD was more accurately identified with TF than TL while MVD was more accurately identified with TL (Table). SVD A

U

O

D

M V D .A

U

O

L)

TL 52.6 15.8 31.6 0.0 TL 55.6 44.4 0.0 0.0 (%) TF 66.7 22.2 0.0 1!.1 TF 42.9 57.1 0.0 00 (%) (A:Accurate, U:Underestimated, O:Overestimated, D:Discrepant). In conclusion, TL was more suitable to evaluate MVD, while it may overestimate the severity of SVD. TF was superior to TL in identifying SVD.

15.59 FAST NINETY MINUTE TC-99M T E T R O F O S M I N S T R E S S - R E S T I M A G I N G P R O T O C O L - RESULTS ON A SMALL SAMPLE M.J.Ferreira, A.I. Ferrer-Antunes, J.Lima, L,A. Provid6ncia. Cardiology and Nuclear Medicine Departraens, University Hospital, C o i m b r a , Portugal Objective:Based on the fact that Tc-99m Tetrofosmin (Tetro) has a faster hepatobiliar clearance than Tc-99m Sestamibi, this study was designed to compare a faster (Ft) one day Stress - Rest (St -R) protocot with the conventional (Cv)St - R protocol with Tetro for myocardial perfusion imaging. M e t h o d s : 14 patients (pts) were submitted to myocardial perfusion scintigraphy by the two different protocols. The two exams were separated by a maximum of 3 months. The Ft protocol was performed as follows: During St 9 mCi of Tetro was injected and images were acquired 15 rain after; the R injection with 22 mCi was given immediatly after and an interval of 20 rnin during which a glass of milk was given to the patient was required belbre starting R images; the Ft protocol was completed in about 90 rain. Images obtained through the Cv and Ft protocols were compared using a visual scoring o f 20 segments, classified from 0 (normal) to 3 (absent uptake). Reversibility (Rev) score was the difference between St and R scores. Results: The mean of the St, R and Rev scores in the Cv v s Ft protocol was respectively: 15,5 v s 21,5; 11,2 v s 1 3 , 4 : 5 , 5 vs 10,2. The visual analysis by areas -anterior (A), septal (S), inferior (I), lateral (L), apical (AP) showed, considering St and R scores and Cv vs Ft: A St - 2,4 vs 3,4, A R - 1,7 vs 1,7; S St - 4,5 v.r 5 , 9 , SR -3,2 vs 3,8; 1 St - 4,4 t,x 5,4, IR -3,4 vs 4,5; L St - 1,7 u s 3,7, LR - 1 vs 1,2; AP S t - 2,6 vs 3,2, AP R - 1,9 v.v 2,1; no statiscal difference was found between the groups. Conclusion: The faster protocol seems to enhance the size o f the defects present on the conventional protocol, but no statiscal difference was found between the groups. This protocol could be an altrnative to the conventional protocol, but larger samples need to be tested.

Journal of Nuclear Cardiology Volume 6, Number 1, Part 2

Abstracts Monday afternoon, April 19, 1999

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COMPARISON OF DIAGNOSIS IN CORONARYARTERIAL DISEASE: THALLIUM-201 CARDIAC TOMOGRAPHY AND PLANAR STUDY. M.F. Tsai, S,J. Yeh, P.F. Kao, K.Y. Tzen. Chang Gung Memorial Hospital, Taipei, Taiwan.

RELATIVE COUNT DENSITY OF OLD INFARCT SEVERE RXED DEFECTS SIMILAR BETWEEN THALLIUM AND TETRAFOSM1N. P. McNelis,W.Vard3ecker. Allegheny University of the Health Sciences, Philadelphia, PA

This retrospectivestudy was performed to compare ~e %201 myocardial perfusion SPECT and planar scinlJgraphy in the diagnosis of coronary arterial disease [CAD]. 240 patients underwent both exercise-redis~bffdon %201 myocardial perfusbn sdnfigraphy and coronary angiography within 30 days with 86 SPECT and 154 planar studies between Jan. 1994 and Oct 1997. 63 SPECT and 130 planar studies were recognized as cases of CAD by the coronary angiography (>50% stenosis in the either left main, left anteriordescending [LAD], left circumflex [LCX], or right coronary [RCA] arteries). The sens~ity/specificity of TI-201 myocardial l:~rfug~on sdnlJgraphy in the LAD, LCX, or RCA territorywere 77%/71%, 31%/98°/o, 77%/79% on the SPECT group, and 72%/85%, 30%/95%, 50%/90% on the planar study group respec'dvely.The specificity,and sensitivi'desof CAD detectbn in paf2ents with single-vessel, double-vessel and Iriple-vesset diseases were 52%, 92%, 91%, 96% on the SPECT group, and 79%, 78%, 85%, 90% on the planar study group respectively. The predictive accuracy of CAD detection in patients with single-vessel, double-vessel and triple-vesseldiseases was 54%, 24%, and 75% on the SPECT group, whereas 47%, 19%, and 33% on the planar study group respec'dvely.The sensilMty of CAD detecl~n in patients with single-vessel disease as either LAD, LCX, or RCA was 100%, 60%, and 100% on the SPECT group, whereas 85%, 67%, and 58% on the planar study group respedJvely. In conclusion, most false-negative results occurred in the patients with single-vesseldisease on the planar study. SPECT does improve accurate interpretationin better detection for the diseased vessel ~ abnormal % 201 dislribution relatively to the higher conlrast resolution and better separationof overlapping myocardialregions.

Radio'cacer uptake/quantitation of defect severity are parameters applied in assessing viability. Bonow, et al (Circ. 1991:83-26) described this for lhallium-201. Technetium peffusion h'acers have less data. We evaluated 9 pts. with clinical old infarcts and severe fixed thallium (TI) defects on stress and re-injection images who had subsequent I day sh~ss-rest tekafosmin (TOstudies withoul new clinical infarct/unstable angina. Relative scar count densitywas done using8 wedgeregiom of interest in short axis sliceswhich well depicted the defect. Count ratios in the scar region to the normal ~ r f t r ~ myocardium gem cak'ulated. Ratios between TI and Tf showed no significantstatisticswith correlations r=0.93 and 0.97, respectivelyfor stress TVstressT| and re-injection T~rest"If. Resul~: (Defectmean counts/ pixel / Normal mean counts / pixeI.)

15.61 HETEROGENEITY OF MYOCARDIAL DISTRIBUTION OF IBMIPP AND TL UPTAKE IN HYPERTENSIVE HYPERTROPHY

H. Fujita, K. Miyao, T. Saknmoto, T. Tc~ur& A_ Matsuo, T. Tanaka, T. Kuriyama, N. lnoue~ M. Kitamum, Kyoto Second Red Cross Hospital, Kyoto, Japan Objective: Slight abnormalities of isotope distribution in hypertensive hyperlrophy were examined u~ng the c(x~cient of variation (CV) in RI uptake. Subjects and Methods: The subjects consisted of 21 patients with hypertensive hypertrophy who had a history of hypertension, did not manifest significant stenosis by cardiac cath~zation and demonstrated concentric hypertrophy on echocardiogram, 54 normal subjects injected with BMIPP and 145 non'nal subjects injected with TI. Using the mean count (M) and standard deviation (SD) from Bull's-eye map of BMIPP and TI, CV={SD/M) X 100 was calculated. "Ihen, CV in hypertensive hypertrophy patients injected with BMIPP was conapared to %FS from echocardiography and WT=septal thickness ffVST) +posterior wall thickness (PWT). Results: CV in hypertensive hypertrophy patients injected with BMIPP was 17.1 ±5.5%, significantly higher than 13.3 ±3.7% in normal subjects (P<0.001). Whereas for TI, there was no significant difference in CV between hypertensive hyperlrophy patients (203 -+4.0%) and normal subjects (19.2±4.7%). CV was not correlated with %FS or WT in hypertensive hypertrophy pafimts injected with BMIPP However, when hypertensive hypemophy patients were das~fied by presence or absence of a history of cardiac insuffidency, CV for BMIPP tended to be higher in the group with inch a history (21.4-+-4.0% vs 133 -f-3.5%). Conclusions: An devated CV for BMIPP was obsevced in some cases of hypertensive hypertrophy compared with thai in normal subjects, suggesting a rdevance to heart function.

R.

StressTF 0.29 035 0.20 0.19 0.21 0.19 0.42

RI TL 0.32 033 0.20 0.19 0.18

7

StressTL 0.26 0.34 020 0.16 0.19 0.22 0A3

0.44

RestTF 0.33 0.35 0.20 0.19 022 0.19 0.43

8

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0.15

0.15

0.18

1

2 3 4 5 6

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9 0.31 0.40 0.30 0.31 Conclusion: Visually and quantitatively, severe defects of old scars look identical in the same patient receiving thallium or teb'afosmin.

15.63 9 9 m T e - F U R I F O S M I N AS A M Y O C A R D I A L V I A B I L I T Y TRACER: QUALITATIVE AND QUANTITATIVE CORRELATION VS SPECT THALLIUM-201, A.Giorgetti, S. Stefanilfi, A. Gimelli, P. Salvadori, P. Marzullo. CNR Institute of ainical Physiology, Pisa, Italy, Recent studies demoi~strated that Thallium-201 (T) and Furifc, smin (F) show similar accuracies in identifying transient myocardial isehemia. However, the potentiality of F in assessing tissue viability is still to be defined. To this aim we compared restredistribution T (111 MBq) and rest F (3700 MBq) SPECT in l g pts (6 male, m e a n age 6 6 , 1 0 yrs) with previous myocardial infarction and depressed ejeetion fraction (0.34<-_.07). SPECT analysis ~ s performed in 101 segments with eehocardiographic baseline dysfunetion~ defects were scored using a 3 point scale (01=normal to moderate, viable; ~severe, necrotic). Furthermore, in short axis planes regional uptake was expressed as % of the maximun~ Normal limits for both tracers were assessed in n o r m a l l y perfused, n o r m a l l y c o n t r a c t i n g r e g i o n s . In dysfunctioning regions an uptake below 2.5 SD of the normal mean was considered as scar. At qualitative analysis, 35135 areas presented a normal to moderate uptake pattern while 59/66 segments showed a severe defect at F and T imaging, respectively. Quantitative analysis showed a preserved uptake in 26/28 dyssynergic areas while 69F73 regions presented a subthreshold uptake of F and T, respectively. In conclusion, F appears a promising tracer for myocardial viability identification with good qualitative and quantitative diagnostic ag/eement when compared to rest-redistribution T sdnfigraphy.

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Abstracts Tuesday morning, April 20, 1999

T u e s d a y A M , April 20, 1 9 9 9 Sessions

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23.1

T U E S D A Y A M A P R I L 20

ESTIMATION OF LEFT VENTRICULAR MASS BY GATED SPECT: COMPARISON WITH 3D ECHOCARDIOGRAPHY O. Akinboboye, G. Germano, O. Idris, M. Verna, L. Coffin, D. Berman, S. Bergmann, D. King. Columbia University, New York, USA. In addition to myocardial perfusion and LV function, gated SPECT (GSPECT) has the potential of assessing LV volume and mass in the same study. The objective of this study was to compare LV mass measurements by GSPECT and by 3D ECHO. Nineteen consecutive patients had 3D ECHO studies performed immediately following their gated stress Tc-99m sestamibi (approx 30 mCi) perfusion studies. Using .commercially available software (QGS), myocardial volume (MV) by GSPECT was estimated as the volume comprised between the endocardial and epicardial surfaces and bound by the valve plane. MV by 3D ECHO was estimated, as the difference between the epicardial and endocardial volumes. MVs by the 2 methods were multiplied by density to yield mass (g) indexed to height 2 (LVMI, g/m2). LVMI by the 2 techniques were compared. Results: Mean LVMI by gated SPECT and by 3D echo were 53 + 12 g/m2 and 53 -I- 13 g/m2, respectively (r=0.68, p=0.0001). The mean difference in LVMI by the two methods was 0.6 - 10 g/m2. Conclusion: LV mass index by gated SPECT and by 3D ECHO correlate. Thus, LV mass, a powerful prognostic index, can be reliably estimated from gated SPECT sestamibi scintigraphy.

23.2 DIAGNOSIS OF SEVERE AND EXTENSIVE CORONARY ARTERY DISEASE (CAD) USING GATED-SPECT MYOCARDIAL PERFUSION SCINTIGRAPHY. Marco Ma~Tanti, Erick Alexanderson*, Diana Victoria*, Patrizia Lemus* and Augusto Purcaro. OspedaleCardlologico"G.M.Lancisi",Ancona, Italy and *lstituto Naeionalde Oardiologia "lgnacio Chavez",Mexico City Left ventricular volumes and ejectionfractions constitute important informations in the diagnosis and prognosis of cardiac disease. Left ventricular ejection fraction obtained from myocardial perfusion gated single-photon emission computed tomography (g-SPECT) have demonstrated accuratecomparisonswith other imaging modalities. Aim of the study is to verify if the assessment of left ventricular function and perfusion together by g-SPECT myocardial scintigraphy is useful for diagnosing severe and extensive CAD. Methods.Separate days stress-rest myocardial perfusion g-SPECT data, acquired 30 to 45 minutes after the injection of 25 mOi of sestarnibi at peak treadmill exercise and 3 hours later using a single head camera, were processed retrospectively in 162 consecutive stable subjects (98 males and 64 females,mean age 59.2 years) with suspected CAD. Endocardial borders and left ventdcular volumes and ejection fraction were generated automatically on paired short-axis Tc-99m sestamibi image set using a 3-dimensional validated software. All pte underwent coronary angiography after scintigraphy. Summed Severity Score (SSS), Transient Ischemic Dilation of left ventricle (TID), left ventdcular Summed Wall Motion Score (SWMS) and Ejection Fraction (LVEF) were calculated using a 4-point scale (O=normal,3=absent uptake) for SSS and 5-point scale (-l=dyski-netic, 3=normal) for SWMS. Results. SVD DVD TVD/prox LAD SSS 3.3 _+0.3 7.0+ 0.9** 13.1+ 0.4",1 TID 0.98_+0.21 1.15+0.24"* 1,25 + 0.32",[ SWM S 47.1 + 5.1 37.2 + 2.2"* 22.3 + 1.4",1 LVEF 0.66+0,12 0.51+0.13"* 0.47+0,141" (*p=O.O05 vs OVD,l"p=O.OOOlvs SVD) and (**p=O.05 vs SVD) Pts who revealedSSS>14, post-stress SWMS<25 and LVEF<0.45 (Ct=mean+2SD) have 98% of likelihood,insteadof 93% using SSS and TID alone, to show significant triple vessel disease (TVD) or >95% stenosis of proximal LAD at angiography. ¢.onclusion. The g-SPECT pattern (low post-stress SWMS and low LVEF) add important diagnostic informations over ungated perfusion data (high SSS, TID) for predicting TVD or severe proximal LAD disease. Gated-SPECT is able to precisely interpret the large amount of post-exercisestunned myocardium still present at time of acquisition.

Journal of Nuclear Cardiology January/February 1999, Part 2

23.3 TETROFOSMIN GATED SPECT EMAGING FOR T~E EVALUATION OF CARDIAC ABNORMALITIES IN SICKLE CELL DISEASE PATIENTS I. Vassiliadis, A. Fountos, A Aessopos, M. Tsh-oni, A. Papademetriou, A. Pe~akis, D. Loukopoulos. Naval Hospital, Laikon Hospital University of Athens, Greece Granted by the International Atomic Energy Agency Cardiac function abnormalities in sickle cell disease (SCD) are well documented, but little information is available with regard to ~rfusion. The aim of this study was to investigate possible myocardial perfusion abnormalities at rest and during exercise as well as functional resting abnormalities in pts with sickle cell 13 thalassemia with a relative new technique and radiotracer. Gated SPECT Tc-99m Tetrofosmin (GST) was performed with a same-day protocol (stress/rest) in 30 consecutive pts(14 males, 16 females) mean age 36+10.2 and mean Hb 9+13g/dl referred for evaluation of clinical cardiac ~anptoms. All were stressed on a treadmill with the Bruce protocol. Perfusion, segmental wall motion and thickness images were analyzed visnaUy and quantitatively. Eight out of the 30 (26.6 %) pts had evidence of stress-indnced perfusion defects. Most of them were localized in the infero-apical area and were accompanied by ST-segment changes. All 10tshad preserved left ventricular function at rest with a mean LVEF 65_+6and no segmental asynergy. A subsequent angiogram in those with abnormal scintigraphic findings revealed normal epicardial coronary vessels. Our data suggest that the incidence of cardiac perfusion abnormalities in SCD is high and can be accurately detected by GST. Since epicardial coronary vessels did not show evidence of atherosclerosis, other factors (hypoxia, sickling process, endothelial dysfunction) may be implicated in myocardial perfusion abnormalities

23.4 PRESENCE OF STUNNING AFTER STRESS TEST; EVALUATED BY MYOCARDIAL PERFUSION IMAGING WITH QUANTITATIVE GATED SPECT(QGS). K Imai, T Nakajima, Y Azuma, K Iwano, S Yamazaki, N Hayafune, M Muto, T Shibata, Y Ogawa, J Suwa, H Horie Saitama Cardiovascular Center, Saitama, JAPAN We evaluated whether stunning was present at 1 hour after stress test in 269 patients by stress and rest myocardial perfusion imaging with Tc-labeled perfusion agent and with one day protocol. Images were obtained by QGS with 8 frames a cardiac cycle 1 hour after injection. Left ventricular enddiastolic volume, end-systolic volume (ESV) and ejection fraction (EF) were measured on QGS. Subjects were divided into 4 groups according to finding of perfusion images; severe ischemia (S-IS, n=35), mild ischemia (M-IS, n=25), myocardial infarct (MI, n = 116) and normal (n=93). Criteria for stunning, post-stress dysfunction, was defined as follows: both 1) delta EF ( EF one hour after stress test - EF rest) < - - 5 % and 2) delta ESV ( ESV one hour after stress test - ESV rest) > 5ml. Stunning° post-stress dysfunction, was found 31% and 20% in S-IS and M-IS. However, It was 9.4% and 4.3% in MI and NOR. Frequency of stunning in patient with S-IS is higher than that in patient with MI and NOR (p<0.01 and p<0.0l). Thus, 1 hour after stress test, stunning was still present.

Journal of Nuclear Cardiology Volume 6, Number 1, Part 2

Abstracts Tuesday morning, April 20, 1999

$39

23.5

23.7

TRANSIENT ISCHEMIC DILATATION RATIO BEFORE AND AFTER CABG IN PATIENTS WITH SEVERE CORONARY ARTERY DISEASE ASSESSED WITH STRESS/REINJECTION TL-201 ECG-GATED SPECT. S. Kubo, E. Tadamura, T. Kudoh, M. Inubushi, N. Hattori, T. Koshiji, K. Nishimura, M. Komeda, J. Konishi. Kyoto University Hospital, Kyoto, Japan It is reported that T1-201 ECG-gated SPECT (TI-gSPECT) can provide functional information if processed with the automated algorithm. Transient ischemic dilatation (TID) of left ventricle on stress / rest perfusion imaging is reported to be clinically useful for the identification of severe coronary artery disease (CAD). Therefore, the purpose of this study was to assess TID change before and after CABG using TI-g-SPECT. In addition, post-stress E F / R e s t - E F (P-R EF ratio) was also evaluated before and after CABG. Fourteen patients with severe coronary artery disease underwent stress / reinjection TI-g-SPECT before and after CABG. TID was larger before CABG than after CABG (1.05 + 0. t4 and 0.92 + 0.11, respectively, p<0.05), while P-R EF ratio did not differ significantly before and after CABG (1.01 + 0.14 and 0.99 + 0.11, respectively). These data indicated that LVEDV transiently increased after stress maintaining LVEF values in severe CAD. After revascularization, however, LVEDV decreased transiently in a post-stress condition preserving LVEF. Thus, stress/reinjection TI-gSPECT provides clinically useful functional information in addtion to the myocardial perfusion and viability.

PHYSIOLOGICALEFFECTSOF DIPYRIDAMOLEON LEFTVENTRICULAR FUNCTION: AMIBIGATEDSPECTSTUDY. PWeinmann JLMoretti AvicenneHospital,UFRL. De VinciPARIS13, Bobigny,France. The effects of dipyridamole (DIP) on myocardial function in healthy subjects have rarelybeen studiedby radionuclidetechniques. MIBIgated SPECTprovidesboth myocardialperfusionand LVEF.Image acquisitionis usuallystarted 60 min after DIP and MIBIinfusion. Therefore,we studied the amplitude and duration of change induced by DIP in 10 subjects (7 women, 3 men, mean age 60 -+ 5 yr) with low likelihoodof CAD.MIBI (740 MBq) was injected at rest, a provocating fatty meal was given and 3 consecutivegated SPECTwere performed 60 min after MIBIinjection : at rest (GS 1), 7 rain afterthe beginningof the infusionof 0.76 mg/kgDIPover a 4 min period(GS2), and 60 min afterthe DIP infusion(GS 3). No patient received aminophyllineafter DIP infusion. Heart rate (HR) and blood pressure (BP) were monitored for each patient. Results are as follows (mean ± sd): p GS1 GS2 GS1 vs GS2 GS3 LVEF '63.1+--9.1 73.2-9.6 <0.0001 62.5---8.1" ~R/ min 82+-12 95.7-+9:5 <0.005 83.9+-12.8' 137.5+16.2 / 132-+16.7/ 140-+23.8 / BPmmHg 81+-9.9 72-+9.8 NS 86-+14.5' * non-significant(NS) : GS 1vs GS3 It is concludedthat : 1) DIP increasesLVEFand HR and has no significant effect on BP in healthy subjects. 2) at 60 min,DIP effectis no morenoticeable. 3) therefore,DIPMIBIgated SPECTas performed in routine, provides a rest LVEF,unlessstunned myocardiumis present.

23.6

23.8

THALLIUM 201 GATED SPECT FOR SIMULTANEOUS ASSESSMENT OF MYOCARDIAL PERFUSION, LEFT VENTRICULAR EJECTION FRACTION AND QUALITATIVE REGIONAL FUNCTION. Ph. Carpentier, H. Benticha, Ph. Gautier, Ch. Sulman. Centre Oscar Lambret, Lille, France.

E F F E C T OF C O R O N A R Y A R T E R Y B Y P A S S SURGERY ON M Y O C A R D I A L PERFUSION AND FUNCTION ASSESSED BY M Y O C A R D I A L GATED SPECT J. Taki, T. Higuchi, K. Nakajima, I. Matsunari, E. Hwang, M. Kawasuji, N. Tonami. Kanazawa University School

This study investigates the faisability of Thallium 201 Gated SPECT and compare left ventricular ejection fraction (LVEF), regional wall motion, and perfusion obtained form Gated SPECT and from echography, radionuclide ventriculography and no gated Thallium SPECT. Method : We studied 40 patients with a Stress/rest Thallium 201 gated SPECT. Automatic quantification of LVEF and wall motion were accomplished using Germano's algorithm. Results : There is a good correlation between LVEF determined from Thallium 201 gated SPECT and from radionuclide ventriculography in all patients ( y = 0,853 x + 6,387 r = 0,934 p<0,05 n=40 ). In ischemic patient ( n= 19 ), the correlation was also good ( r = 0,933 ). Exact agreement between rest Thallium 201 gated-SPECT and echocardiography segmental motion was 88,8% ( Kappa = 0,64 p<0,05 ). Concerning perfusion defect observed at rest with gated SPECT and non gated SPECT the agreement was good (Kappa between 0.73 and 1) C o n c l u s i o n : Thallium 201 gated SPECT imaging can be performed to assess simultaneously both myocardial function and perfusion using one injection.

The aim of this study was to assess the change of myocardial perfusion and ventricular function before and after bypass surgery (CABG) using gated SPECT with Tc-99m-MIBI. 20 patients with chronic coronary artery disease underwent gated SPECT before and 1 month after CABG. Enddiastolic and end-systolic volumes (EDV, ESV), LVEF, global and regional systolic % wall thickening (WT), and regional perfusion (% uptake) were evaluated. For regional analysis, myocardium was divided into 16 segments on functional bull's eye map. Patients with preoperative EF with <50% showed larger decrease in EDV(-23+_21ml vs -8.9+7.3ml, p=.09) and ESV(-19+20ml vs -2.1+3.1ml, p<.05) and increase in global W T (6.1+11% vs -4.2_+10%, p<.05) after CABG than those with >50%. The segments with preoperative WT with <35% showed increase in W T (23+8.5% to 28+12%, p<.001) and perfusion (69+14% to 72+14%,.p<.001) after CABG. While, the segments with preoperatwe W T with >35% showed same perfusion (82+ 8.7% to 82+8.3%) and reduction in W T (55+14 to 51+ 16 %, p<.001). In conclusion, serial myocardial gated SPECT before and after CABG provides comprehensive information on changes in myocardial perfusion and function.

of Medicine, Kanazawa, Japan

$40

Abstracts Tuesday morning, April 20, 1999

Journal of Nuclear Cardiology January/February 1999, Part 2

23.9

23.11

A NEW APPROACH TO STUDY MYOCARDIAL VIABILITY. E Becker, E Alexanderson, D Victoria, J Apolo, T Colmenares, P Lemus, D Bialostozky. Instituto Nacional de Cardiologia "'lgnacio Chavez".Mexico City, MEXICO TI-201myocardial uptake in late 24 hours redistribution imaging or after reinjection are considered the best nuclear protocols to recognize myocardial viability. Low dose dobutamine can recognize viable myocardium increasing regional wall motion and gIobal ejection fraction. Gated SPECT can evaluate simultaneously myocardial perfusion and wall motion. The aim of this study is to asess the utility of low dose dobutamine using gated spect in identifying myocardial viability. METHOD : We studied patients with prior myocardial infarction using TI-201/Tc 99m sestamibi dual isotope protocol with 24 hrs late redistribution thallium images. Perfusion data were read using 20 SPECT segments analysis and each segment was scored using a 5 points scoring system (0=normaI, 4=absent uptake). To study wall motion we divided the heart in 29 segments and every segments was scored using a 4 points scale ( 3=normal. 2=mild bypokinesia, 1= severe hipokinesia. 0=akinesia). After the normal stress acquisition acquired by gating the images, we performed a second gated spect acquisition during infusion of 5 and 10 mg/Kg/min of dobutamine. We evaluated the changes in pert'usion, wall motion and LVEF.RESULTS :

* Mostly due to infarcted myocardium ** Mostly due to non - infarcted myocardium Most of the segments with late redistribution TI-201 images showed an increase of wall motion after low dose dobutamine infusion. CONCLUSIONS : In the preliminary study, low dose dobutamine infusion with gated spect acquisition give additional information for recognition myocardial viability.

23.10

ASSESSMENT OF SEPTAL ASYNERGY AFTER CORONARY ARTERY BYPASS SURGERY BY MYOCARDIAL GATED SPECT T. Higuchi, J. Taki, K. Nakajima, I. Matsunari, E. Hwang, M. Kawasuji, N. Tonami. Kanazawa University School

of Medicine, Kanazawa, Japan The aim of this study was to assess the septal asynergy after bypass surgery (CABG) in association with myocardial perfusion and systolic wall thickening using gated SPECT with Tc-99m-MIBI. 18 patients with coronary artery disease underwent gated SPECT before and 1 month after successful CABG. Global and regional ejection fraction (EF), regional systolic % wall thickening (WT), and perfusion (% uptake) were evaluated. Regional analysis was performed in 16 segments on functional bull's eye map. LVEF tended to increase after CABG (53.9+17.5% to 57.7+16.3%, p=0.18). Septal perfusion increased from 73.3+8.4% to 76.7+ 8.3% (p=.012) and that in other segments did not change (78.0-!-_7.3% to 78.9-Z-_6.7%, p=.31). WT in septum and in other segments did not change (41.6 +14.9% to 41.5+18.6%, p=.96, 44.6~.16.8% to 42.2.~_15.9%, p=0.49, respectively). However, septal EF decreased from 14.9-2_12.6% to 6.3+7.9% (p<.02) and EF in other segments increased from 36.7 +10.9% to 42.3+10.5% (p<0.001) after CABG, suggesting artifactual change of regional EF. In conclusion, myocardial gated SPECT may be a useful method to assess changes in myocardial perfusion and function despite septal artifactual asynergy after CABG.

23.12

INFLUENCE OF EXTENSION AND SEVERITY OF PERFUSION DEFECTS OVER EJECTION FRACTION. E Alexanderson, P Lemus, T Colmenares, E Becker, J Apolo, J Rubinstein, A Arroyo, D Bialostozky, D Victoria. Instituto Nacional de Cardiologia "lgnacio Chavez".Mexico City, MEXICO. Gated SPECT allows simultaneous evaluation of myocardial perfusion and ventricular function giving probably more diagnostic and prognostic information. The aim of the study is to analyze the correlation between the extension and severity of perfusion abnormalities and the ejection fraction obtained with Gated SPECT program. METHOD: We studied 288 consecutive patients with coronary artery disease. We used rest thalliumstress sestamibi dual isotope protocol in patients with history of myocardial infarction (MI) or one day rest-stress sestamibi in the group of patients without MI. Perfusion data were read using 20 SPECT segment analysis and each segment was scored using 5 points scoring system (0=normal.4=absent uptake).Summed rest score(SRS), summed stress score(SSS) and the difference between SSS and SRS(DS)were obtained.Ejection fraction was obtained automatically from Cedars-Germano program. RESULTS:

* p < 0.001

* p < 0.001

POSTISCHEMIC STUNNING FOLLOWING STRESS EFFECTS LEFT VENTRICULAR FUNCTION IN PATIENTS WITII A PP, EVIOUS MYOCARDIAl_, INFARCTION. CDL.Croon,DE.Atsma, P.Dibbets, EKJ.Pauwels EE.van der Wall.Leiden University Medical Center, Leiden, Netherlands. B a c k g r o u n d : Gated SPECT myocardial perfusion imaging provides information on left ventricular (LV) end-diastolic vohune (ml) (EDV), end-systolic volume(ml) (ESV) and ejection fraction (LVEF). We compared these parameters one hour after rest injection and 30 minutes post-stress in patients (pts) with anginal chest pain. Methods: We evaluated 29 pts of whom 17 with and 12 without a previous myocardial infarction(Ml). All pts underwent gated SPECT myocardial perfusion imaging twice: one hour following 99m Tc-tetrofosmm injection at rest and 30 minutes post-stress. Results: Changes 30 minutes )ost-stress compared to rest: A L V E F (%)

** p > 0.05

** p > 0.05 ***p < 0.05 CONCLUSIONS:The extension and severity of perfusion defects influence ejection fraction, specially when SRS and SSS are more than 12 and LAD or left circunflex are the affected vessels. There is not significant influence between the number of affected vessels or the degree of ischemia and the ejection fraction.

AEDV (%)

AESV ( % )

M I + (17)

-2.7_+5.4

+9.3_+15.4

+16.4_+22.3

M I - (12)

+2.1_+2.4

+3.0_+7.3

+0.3_+10.7

p (ANOVA)

0.008

0.2

0.029

Conclusion: Unlike pts without MI, pts with a previous MI showed signilicant changes in LVEF and ESV 30 ufinutes poststress compared to the rest situation. This phenomenon may be due to LV stunning in pts with previous MI.

Joumat of Nuclear Cardiology Volume 6, Number 1, Part 2

Abstracts Tuesday morning, April 20, 1999

$41

23.13

23.15

Assesment of Endothelium Function with Gated SPECT Perfusion Dipyddamole and Cold Stress Test Imagings in Patients with Coronary Artery Disease. Osvaldo Masoli, Perez Balifio Nestor, Cados Rapallo, Daniel Cragnolino, Alejandro Merotta. Tch. Nestor Blanco, Horacio Tallone. Instituto Cardiovascular de Buenos Aires, Argentina. Pharmacological dipyddamole stress has a vasodilator effect non endothelial dependent. The cold stress test has been related to endothelium dependent mechanism,different than dipyridamolestressto producevesodilatation. The aim of the study was to differenciate ischemia ralated or not to endothelium mechanisms in patients with coronary artery disease (CAD) with ~qc Sestamibi Gated SPECT. Three hundred segments in 15 patients (pts) with CAD underwent quantitative coronary angiography {QCA) end ~"q'c Sestarnlbi Gated SPECT according to standardized protocols. Dipyddamole, cold stress test and rest were done in consecutivein days. Interpretation of Gated SPECT imageswere done in a 20 segments model to evaluate severityof the perfusion defects. One hundred and sixty four segments were normal with dipyddamole stress, cold stress test and rest peffusion images with normal wall motion and thickening, 97 segments were fixed defect in dipyddamoleand cold stress test and rest with abnormal wall motion and thickening. Twenty five segments had reversible peffusion defects with both stress test. Six segments developed reversible defects only with dipyddamole and 8 segments only with cold stress test. (p=NS). The media rest LVEF. was 65.0 +/- 3 %. Thus, in our population with CAD the mismatch pattern between dipyddamole and cold stress test could evidence diferents ischemic patophisiologicalmecanisms. The cold stress test reversible defects evidenced CAD associated at endothelial disfunction as the mayor mechanism.

RESTING PERFUSION IN CHRONIC CORONARY ARTERY DISEASE (CAD) PATIENTS WITH LEFT

23.14 A P P L I C A T I O N OF E C G - G A T E D Tc-99m S E S T A M I B I CARDIAC IMAGING TO PATIENTS WITH ARRHYTHMOGENIC RIGHT VENTRICULAR D Y S P L A S I A (ARVD). M.Toba, Y.Ishida, K.Fukuchi, K.Fukushima, M. Takamiya. National Cardiovascular Center, Osaka, Japan. Right ventricular (RV) dysfunction is predominant in patients with ARVD, however, left ventricular (LV) dysfunct!on is often also present and may determine the prognosis. Since cardiac pool imaging is ditical for assessing LV function in cases of RV enlargement, we applied Tc-99m sestamibi cardiac imaging with first-pass radionuclide angiographic ( F P - R N A ) and ECG-gated myocardial studies to 10 patients with ARVD, and evaluated its usefulness by comparing the results to those from electron beam CT (EBCT). The RV eiection fraction (EF) by F P - R N A and L V E F b y the quantitative gated S P E C T ( Q G S ) program (Germano, 1995) were closely correlated to those obtained by E B C T (r=0.75, p<0.02 and r=0.94, p<0.01, respectively). The QGS program provided accurate measurement of the L V E F in such cases of marked RV dilatation. E B C T detected the extension of myocardial fatty infiltration to LV in 6 of the 10 patients. The ability of myocardial perfusion S P E C T in detecting these lesions was 95% in sensitivity and 98% in specificity. These 5 patients showed more reduced L V E F than the other patients ( 3 8 + 1 5 % vs. 66+5%, p<0.02). These results suggest that Tc-99m sestamibi cardiac imaging which provides assessment of RV function(by F P - R N A ) and LV myocardial lesions and function (by ECG-gated myocardial SPECT) is very useful for the diagnosis of ARVD.

VENTRICULAR (LV) DYSFUNCTION HS BOM, HC SONG, HJ JEONG, JJ MIN, JY KIM. Chonnam University Hospital, KwanNu, Korea. The

purpose

of

this

study

was

to

determine

the

prevalence of hibernation and repetitive stunning in CAD with LV dysfunction. By definition, repetitive stunning was diagnosed when resting perfusion x\as normal while pts with diminished resting perfiJsion xxas diagnosed as hibernating

myocardium "Fifty three

chronic

CAD

pts

with LV dysfunction (39 males, 14 females, mean age 59 years)

who

revascularization

showed were

improved studied

LV

by

function

Tc-99m

after

tetrofosmin

gated myocardial SPECT before revascularization. Resting pcffnsion was normal in 25 (32%),

mild-to-moderately

diminished in 46 (59%), and severely diminished in 7 (9%). No clinical or angiographic factors was associated with repetitive stunning one-third

or hibernation.

of viable mvocardium

in

In conclusion,

chronic

CAD

pts

shmxcd normal resting perfusion indicating stunning.

23.16 PREDICTION OF FUNCTIONAL OUTCOME IN STUNNING MYOCARDIUM AFTER MOYCARDIAL INFARCTION USING BMIPP A N D TETROFOSMIN I M A G I N G S . T.Ueda, T.Toyama*, H.Hoshizaki*, M.Suguta*. N.lsobe*, S.Oshima*, K.Taniguchi* and R.Nagai. Gunma University school of Medicine and *Gunma Prefectural Cardiovascular Center, Maebashi, Japan. We determined the predictive value of combined 1-123 beta-methyl iodophenl pentadecanoic acid (BMIPP) and Tc-99m-Tetrofosmin (TF) imagings for the functional outcome of stunning myocardium after acute myocardial infarction (AMI) and compared the value of combined BMIPP and TI imagings. Methods: Rest BMIPP, rest TF and rest TI imagings were obtained at 15 minutes after tracer injection in 15 patients 4 to 10 clays after a@nission, who -all were reperfused successfully. TF imaging was also obtained 5 months later. In 20 segment of SPECT image, regional tracer uptake (DS) was scored by using a 4-point scoring system (0--normal to 3--defect). The segment was considered to show mismatching, when the BMIPP score was over the TF or T1 score, and to show matching, when the scores were the same. TF imaging was obtained by quantitative gated SPECT (QGS), and estimated wall motion using a 5-point scoring system (-1= dyskinesis to 3= normal) in the same perfusion segments. Results; The sensitivity and specificity of mismatching of TF and BMIPP or TI and BMIPP uptake on the basis of the improvement in wall motion was shown below the table. Sensitivity Specificity Mismatching of TF and BMIPP 92% (69/75) 73% (16/23) Mismatching of Tl and BMIPP 57% (43/75) 74% (17/23) Mismatching of TF and BMIPP uptake can predict the improvement of wall motion after AMI more than that of TI and BMIPP uptake. CombinedTF and BMIPP is useful to predict functional outcome of stunning myocardium after AMI.

T U E S D A Y A M A P R I L 20

$42

Abstracts Tuesday morning, April 20, 1999

23.17 PREDICION OF FUNCTIONAL RECOVERY BY Tc99m TETROFOSMIN SPECT AFTER CORONARY BY PASS SURGERY IN PATIENTS WITH SEVERE LEFT VENTRICULAR DYSFUNCTION. KF Kofoed, B Hesse, R Bangsgaard, S Carstensen, A Rab¢l, J Hove, JH Svendsen, PR Hansen, H Arendrup & H Kelb~ek. The Heart Centre, Rigshospitalet, Denmark

T

U E S D A Y

The benefits of coronary bypass surgery (CABG) in patients with severe left ventricular dysfunction may be due to recovery of myocardial contractile function. The aim of this study was to test the ability of Tc99m Tetrofosmin (TF) SPECT to predict functional improvement in such patients. Methods We prospectively studied 49 consecutive patients with multivessel disease and severe left ventricular dysfunction (LVEF 31+7%). A pre-CABG rest TF SPECT study was performed. TF uptake was quantitated (16 segments) by circumferential profile analysis. Viable myocardium was defined as TF uptake >50% of peak. Systolic wall thickening (2D echo) was assessed at a median o f 2 weeks before and 7 months after CABG. Results At followup all patients except 4 had a negative exercise-ECG. Before CABG 61% of visualized segments (322/498) had abnormal contraction. In 49% (157/322) of these segments TF uptake was >50% ofpeak. The prevalence of functional improvement after CABG was 16% (44/279). The positive predictive value for the prediction of improvement in systolic wall thickening was 21% and the negative predictive value was 89%. Conclusion In patients with severe left ventriuclar dysfunction Tc-99m Tetrofosmin SPECT is accurate by excluding the presence of viable myocardium.

A M A P R I L 20

Journal of Nuclear Cardiology January/February 1999, Part 2

23.19

REVASCULARIZATION OF VIABLE MYOCARDIUM INFLUENCES OUTCOME INDEPENDENTLY OF THE RECANAMZATION PROCEDURE. A. Gimelli, P. Marzullo, CNR Institute of Clinical Physiology, Pisa, Italy, on behalf of the VIP study. In patients (pts) with ischemic global left ventricular dysfunction and maintained viability, little is known on the effect o f different type of revascularization procedures on long-term outcome. To this aim, 228 pts with documented coronary artery disease, previous myocardial infarction and an ejection fraction below 45% underwent percutaneous transluminal coronary angioplasty ( P T C A , 70 pts, 91% on the left anterior descending coronary artery, LAD) or multiple coronary artery by-pass grafting (CABG, 158 pts, 93% arterial conduit to LAD) and were followed-up for 32+11 months. All pts showed dominance of tissue viability in dyssynergic areas demonstrated by Thallium-201. Pts were matched for all known determinants o f postinfarction prognosis. Cumulative survival at 3 years was 91% and 92%, respectively in pts revascularized by PTCA and C A B G (log rank = 0.2547). In conclusion, in patients with depressed ejection fraction and viable myocardium, revascularization is associated with a favourable long-term outcome; this results is obtained independently from the revascularization procedure. Revascularization of the LAD is probably the main determinant of improved outcome.

23.18

23.20

PREDICTION OF FUNCTIONAL RECOVERY AFTER REVASCULARIZATION BY RESTING NITRATE 99mTCTETROFOSMIN QUANTITATIVE SPECT SCINTIGRAPHY. A.R. Galassi, S. Azzarelli, G. Rodi, R. Foti, S, Musumeci, G. Giuffrida. Institute of Cardiology, University of Catania, Italy.

PROGNOSTIC VALUE OF REVASCULARIZATION IN PATIENTS WITH VENTRICULAR DYSFUNCTION

To determine the role of nitrate 99mTc-Tetrofosmin SPECT scintigraphy in predicting reversibility of regional wall motion abnormalitiesafter successful revascularization we studied 14 patients with previous myocardial infarction and left ventricular dysfunction (mean ejection fraction of 38_.10%). All patients underwent 99mTcTetrofosmin resting quantitative SPECT scintigraphy after nitrate administration (0.005 mg/Kg per os) and 2D echocardiography pre and 5+_2months after revascularization. By scintigraphy, segments with severe defects (<50% of maximal activity) were considered nonviable. By 2D echocardiography wall motion was scored from 1 (normal) to 4 (dyskinesia) and viability was defined as wall motion change >_1 grade after revascularization in dysfunctional segments. Twelve over 62 segments (19%) with wall motion abnormalities and severe scinligraphic defects showed significant increase in percentage uptake after revascularization (>50%) as compared to the remr:~ing 50 segments which did not show any significant change (p
AND HEART FAILURE SYMPTOMS.

A. Gimelli, P. Marzullo, CNR Institute of Clinical Physiology, Pisa, Italy, on behalf of the VIP study. The prognostic benefit of coronary revascularization in ischemic congestive heart failure has been well documented only in patients (pts) with angina. Aim of this study was to define the impact of revascularization in N Y I t A III-IV pts with previous myocardial infarction, mostly viable myocardium at Thallium-201 scintigraphy, with (Group A) and without (Group B) anginal symptoms. One hundred and seventy pts (88 of Group A and 82 of Group B), with documented coronary artery disease, a mean ejection fraction of 28_+9%, were followed-up for 3 years. The 2 groups did not differ with respect to known determinants of postinfarction prognosis. Forty-nine % pts of Group A and 42% pts of Group B were treated with revascularization. At 3 years, revascularized pts of Group A showed a better outcome versus medical pts (92% versus 68%, respectively, log rank=.0013). Similarly, the survival of revascularized Group B pts was 90% versus 67% of the medical group (log rank: 0.021). In conclusion, in pts with left ventricular dysfunction, revascularization induces a better outcome even in absence of anginal symptoms. These findings expand the indications for coronary revascularization in ischemic heart failure pts with suitable coronary anatomy.

Journal of Nuclear Cardiology Volume 6, Number 1, Part 2

Abstracts Tuesday morning, April 20, 1999

$43

23.21

23.23

ADVERSE PROGNOSTICMEANING OF VIABILITY DETECTIONWITH SESTAMIBIIN CAD PATIENTSWITHLV DYSFUNCTION.

V I A B I L I T Y ON F D G S P E C T IS R E L A T E D TO IMPROVEMENT OF HEART FAILURE SYMPTOMS AFTER REVASCULARIZATION. J.J.Bax, J.H.Cornel, F.C.Visser, P.M.Fioretti, D.Poldermans, C.A.Visser. Leiden, The Netherlands.

M.Pellegri, R.Sciagr&, S.Sestini, G.M.Santoro, D.Antoniucci. Nuclear Medicine, University of Florence; Florence, Italy. PET and thallium-201 studies have demonstrated that viability detection implies an adverse outcome in chronic CAD patients with LV dysfunction kept on medical therapy. We examined the relation between Sestamibi demonstration of viability using baseline-nitrate SPECT and long-term outcome in 105 patients. The referring cardiologists independently made therapeutic choices. The events considered during follow-up were cardiac death, nonfatal myocardial infarction and untreatable unstable angina or congestive heart failure requiring late revascularization. The follow-up was 27 _ 22 months, during which 21 events were registered. The event rate in patients without viability (group 1)was 7%. In patients with preserved viability, the event rate was 10% in those submitted to complete revascularization (group 2), 45% in those kept on medical therapy (group 3) (p < 0.005 vs. groups 1 and 2), and 32% in those submitted to incomplete revascularization (group 4) (p = 0.05 vs. group 1, p = 0.06 vs. group 2, NS vs. group 3). These data confirm that viability detection with Sestamibi achieves results comparable to PET and thallium-201 also in terms of prognostication. Furthermore, they suggest that complete revascularization is mandatory in patients with chronic CAD and LV dysfunction if they show signs of preserved viability.

Pre-operative

viability

is

related

to

post-operative

improvement of resting LV function. It is unknown whether the improvement in LV function translates in improvement of heart failure (HF) symptoms. We evaluated the relation between pre-operative viability (assessed by FDG SPECT), post-operative change in LV function and post-operative change in HF symptoms. Patients (n=32) with chronic CAD and depressed LVEF, scheduled for revascularization, were studied. A patient was classified viable when _>3 dysfunctional segments were viable on FDG SPECT. LVEF and HF status (NYHA-criteria) were assessed before and 3 months post-revascularization. Results: in 18 patients with >3 viable segments on SPECT, the LVEF improved from 27_+8% to 34_+9% (P<0.05) and the NYHA score from 2.9_+0.3 to 1.5_+0.7 (P<0.01). In 14 patients with <3 viable segments the LVEF (31_+8% vs 31_+8%, NS) and the NYHA score did not improve (2.6_+0.5 vs 2 . 4 + 0 . 7 , NS). Conclusion: patients with substantial viable tissue did improve in LVEF post-operatively; the improvement in LVEF was accompanied by improvement in HF symptoms.

T U E S D A Y A M

23.22

23.24

PRESENCE OF REVERSIBLE ISCHAEMIA PREDICTS LONG TERM IMPROVEMENT 1N LEFT VENTR1CULAR FUNCTION AFTER REVASCULARISATION IN PATIENTS WITH ISCHAEMIC CARDIOMYOPATHY

DOBUTAMINE ECHOCARDIOGRAPHY AND Tc-99m SESTAMIBI SPECT IN THE PREDICTION OF FUNCTIONAL RECOVERY AFTER ACUTE MYOCARDIAL INFARCTION. W. Acampa, A. Cuocolo, L. Spinelli, M. Petretta, E. Nico[ai, L. Vicario, D. Bonaduce. University Federico 11, Napoli, Italy. Myocardial stunning and hibernation contribute to postinfarction left ventricular dysfunction. Identification of" dysfunctional viable myocardium is important considering that functional recovery may be observed spontaneously or following coronary revascularization. Forty-nine patients underwent coronary angiography, low-dose dobutamine echocardiography and rest sestamibi imaging within 10 days after acute myocardial infarction. Of these patients, 19 were revascularized and 30 tl'eated medically. Resting echocardiogram was repeated 8 months later to evaluate functional recovery. In revascularized patients, 61 of 108 a-dyskinetic segments showed functional recovery. In these patients, sensitivity in predicting functional recovery was 87% for sestamibi and 66% for dobutamine echocardiography (p<,001), while specificity and accuracy were comparable. In medically treated patients, 60 of 149 a-dyskinetic segments showed functional recovery. In these patients, sensitivity was comparable with both techniques, whereas specificity and accuracy were higher for dobutamine than sestamibi (90% vs 61%o; p<.001 and 89% vs 74%; p<.01, respectively). The strongest predictor of functional recovery wets sestamibi activity in revascularized patients (p<.001) and inotropic response in medically treated patients (p<.001). In conclusion, dobutamine echocardiography predicts functional recovery after myocardial infarction. However, sestamibi imaging is useful to identify dysfunctional segments without contractile reserve that may benefit by revascularization.

R Senior and A Lahiri. Harrow. UK

Northwick Park Hospital,

We have hy,pothcsised that rcvascularisation (rev) should improvc LV functiou ill paticnts with ischaemic cardiomyopathy who showed evidence of effort induced ischaelnia. Accordingly, treadmill exercise-rest Tc-99m scstamibi SPECT and rest cchocardiography were performed in 57 pts with symptomatic LV dysfunction (LVEF=25:k8%) due to CAD. LV function was assessed by calculating tile sytolic wall thickening index (SWTI). Reversible ischaemia was demonstrated in 11 (49%) out of" 23 pts x\ho underwent Rcv and 18 (54%) out of 34 pts on medical therapy. There was a significant improvement in SWTI (p=0.01) at a mean follow-up period of 14±4 lnonths only in pts with reversible ischaemia who underwent rev. Thus, presence of reversible ischaemia predicted long term ilnprovement in LV function after rev in pts with ischaemic cardionlyopathy.

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23.25 Prediction of functional outcome after revaseularization by serial dual-isotope Tc-99m-Tetrofosmin and 18-FDG SPECT and dobutamine stress echo in patients with severe LV dysfunction. D. Poldermans, R. Valkema, J.J. Bax, R. Rambaldi, E.P. Krenning. Thoraxcenter, Erasmus University, Rotterdam, the Netherlands. Aim To assess changes of dual-isotope simultaneous acquisition (DISA) SPECT with Tetrofosmin / FDG and dobutamine stress echocardiography (DSE) before and after CABG in relation to functional improvement in pts with severe LV dysfunction using RNV as a reference. Methods: 36 pts, mean EF 34% (range 10-39%) underwent RNV, DISA-SPECT and DSE before and 9 months after CABG. Both DSE and DISA-SPECT were scored using a 16-segm model. Viability was scored by DSE by an improved wall motion and/or ischemia, by DISA-SPECT: normal FDG uptake or mismatch of Tetrofosmin / FDG. DSE after CABG was scored for improvement of basal contraction and contractile response during DSE. Improved contractile response indicated an improved wall motion during DSE without the occurrence of ischemia. By DISA-SPECT for Tetrofosmin / FDG changes. EF improved if RNV increased >5.%. Data are presented as odds ratio's [OR] with 95% CI. Results: 268/576 segm showed dyssynergy at rest and were suitable for grafting. EF improved in 9/36 pts. Sens and spec for predicting segm improvement by DISA-SPECT and DSE was 85/90% and 84/82%. Improved EF correlated with both improved basal contraction and contractile response during DSE: OR 3.3 [2-6] and 8.1 [4-16] and increased Tetrofosmin and FDG uptake; OR 4.1 [2-9] and OR 6.4 [3-12]. Conclusion: After CABG both basal segmental improvement and contractile response were related with improvement of EF in pts with severe LV dvsfunct.ion.

23.26 COMPARISON BETWEEN LOW-DOSE DOBUTAMINE GATED-SPECT AND ECHOCARD1OGRAPHY FOR DETECTION OF CONTRACTILE RESERVE. G. Marcucci, *M. Leoncini, M. Silvestri, *L. Bini, *M. Magni, *F. Frascarelli, A. Arena, C. De Gaudio, *G. Lauri, *A. Petrella, A. Mennuti. Nuclear Medicine and *Division of Cardiology, Prato Hospital, Italy. Aim of the study was to compare Tc-99m sestamibi gated perfusion tomograpby (G-SPECT) and echocardiography (ECHO) for the assessment of contractile reserve during low-dose dobutamine (LDD). Twenty-five patients with chronic CAD, resting asynergy and left ventricular dysfunction (ejection fraction: 30±12) underwent LDD-ECHO and Tc-99m sestamibi G-SPECT at rest and during LDD infusion. Wall motion (WM) was scored from 1 (normal) to 4 (dyskinetic) using a 16-segment model for both ECHO and GSPECT. Left ventricle was divided into three vascular territories. A territory was difined as viable by LDD-ECHO and by LDD GSPECT when at least two contiguous segments showed improvement or decrease _> 1 grade of resting asynergy. RESULTS: Forty-seven asynergy vascular territories were considered. Contractile reserve was detected by LDD-ECHO in 28 territories of which 21 (75%) were identified as viable by LDD G-SPECT. Fifteen of 19 (79%) nonviable territories at LDD-ECHO were defined as fibrotic by LDD G-SPECT. Agreement between the two metbos was 77%. Significant correlations (Spearman's 9) between ECHO and G-SPECT were found for rest-WM (9=0.64; p<0.0001) and LDD-WM (9=0.67; p<0.000001). Conclusions: 1) for detection of contractile reserve LDD G-SPECT is comparable with LDD-ECHO; 2) LDD G-SPECT may be an useful method to assess myocardial viability by combining both perfusion and contractile reserve.

Journal of Nuclear Cardiology January/February 1999, Part 2

23.27 EVALUATION OF MYOCARDIAL VIABILITY USING DOBUTAMINE STRESS GATED SPECT IN PATIENTS WITH OLD MYOCARDIAL INFARCTION (OMI). S. Sato, K. Kimura, M. Inagaki, J. Tsuzuki, S. Kamiya, N. Murayama. Daido Hospital, Nagoya, J a p a n . We studied Tc-99m Sestamibi (MIBI) gated SPECT with

low dose dobutamine stress in patients with old myocardial infarction, and evaluated the viability in the area of infarction that is represented by wall motion processed with QGS program, and then assessed the usefulness of this method by comparing the data with the regional % uptake of resting MIBI SPECT images performed on the same day. The study population consisted of a5 patients (32 males, 3 females, mean age: 63.3 years). We started eontinuos instillation of 4.7 7 of dobutamine, and 5 minutes after the stabilization of hemo-dynamics,intravenously administered 800 MBq of MIBI.We cinematically displayed the images of end diastolic and end systolic endocardial surfaces. Wall motion in 8 regions was evaluated visually on a scale with 4 steps. In 37 regions with % uptake under 50 % that were judged as having no viability from the images, low dose dobutamine stress improved wall motion in 9 regions, which is 24.3 % .In regions with % uptake of between 50% and 79%, abnormal wall motion was detected after stress. It is useful to perform MIBI myocardial gated SPECT with low dose dobutamine stress and evaluate wall motion using QGS program in the assessment of viability in the area of infarction.

23.28 MYOCARDIAL PERFUSION ECG GATED SPECT IMAGING WITH LOW-DOSE DOBUTAMINE IN THE PREDICTION OF MYOCARDIAL VIABILITY. ' J" Marti, S. Vidal-Sicart, C. Par6, C. Laterza, , JJ. Mateos, A. Muxi. Clinic Hospital. Barcelona. Spain The clinical utility of low dose dobutamine infusion (LD) during the acquisition of ECG gated SPET imaging (GS) for the assessment of viability has not been established. We have studied 12 patients (2 females, mean age 61 +9 years) with segmental wall motion abnormalities (SWMA) scheduled for revascularization (CABG). Seventy minutes after the injection of 20 mCi of Technetium-99m-Sestamibi, a basal GS was performed. When the acquisition was completed, 5 ugr/Kg/min dobutamine was infused for 5 min. It was followed by a second GS performed during the administration of LD (10 ugr/Kg/min) (GSLD). Three months after CABG a GS at rest without GSLD was also performed. We have only considered the segments with basal SWMA (n=57). The images were evaluated usmg a scored 16 segment model (Perfusion: 0-4, normal-non uptake; GS cine mode: 1-4, normal-akinesis) The wall motion of segments which improved in the GSLD showed a significant ( = p < = 0 . 0 0 1 ) improvement after CABG. Segments

n

Improvement 14 Non improvement 43 after CABG

PerfusionScore 1.71 2.39 ns

GS Score 2.50 2.77 ns

GSLD Score 1.36 2.84 p < 0.001

In conclusion, GSLD may be an useful tool in the evaluation of myocardial viability. Further studies in a larger number of cases are warranted.

Journal of Nuclear Cardiology Volume 6, Number 1, Part 2

Abstracts Tuesday morning, April 20, 1999

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23.31

LEFT VENTRICULAR PERFUSION AND FUNCTION USING GATED-SPECT SCINTIGRAPHY IN PATIENTS WITH PREVIOUS MYOCARDIAL INFARCTION. Marco Ma77anti, Erick Alexanderson*, Diana Victoria*, Patrizia Lemus* and Augusto Purcaro. Ospedale Cardiologico "G.M.Lancisi", Ancona, Italy and "lstituto Naeional de Cardiologia "lgnacio Chavez",Mexico City

R E G I C N A L W A L L M O T I C N Q C R R E L A T E D W I T H GI..CBAL L V FUNCTION BETTER THAN WALL THICKENING: ASSESSMENT BY QUANTITATIVE GATED SPECT I Adachi, K Morita, M Konno, MB Irnran, N Kubo, T Mochizuki, N Tamaki.

Gated 99mTc-sestamibi single-photon emission computed tomography (g-SPECT) have demonstrated to be accurate for evaluation of post-stress viable ischemic myocardium. Aim of the study is to detect if post-stress left ventricular ejection fraction (LVEF) can add informafions over perfusion alone in patients (pts) with previous myocardial infarction (MI). Nethade. Rest TI-201 (r-TI), (2.5 to 3.5 mCi) and peak treadmgl exercise 99mTc-sestamibi (s-Tc), (20 to 30 mCi) were injected in 94 pts with history of previous M[ (dated 21 - 48 days before, mean 35.4). The tocation of MI was anterior in 39 pts, inferior in 45 pts and anterior + inferior in 10 pts. All g-SPECT studies were acquired using a single head camera after 5-10 minutes and 30-45 minutes r-TI and s-Tc injection respectively. Left ventricular volumes and LVEF were generated by an automated 3-dimensional validated software. Summes severity score (SSS) and summed reversibility score (SRS) were Calculated using a 4-point scale (g=normal, 3=absent uptake). We defined high SSS if 2 8, high SRS if _>50% of SSS, low SRS if < 50% of SS8, low LVEF if _<0.40 and normal LVEE if > 0.40. Clinical follow up (73-96 days, mean 78.2) of pts was studied to check soft events (angina, symptomatic left ventricular dysfunction and complex arrhythmJas). ~esults. Group A Group B Group C (21 pts) (18 pts) (20 pts) SSS 9.0 + 1.4 9.3 + 1.6 9.9 _+1.8 SRS ~ 5.2_+1.3 3.34-0.7 4.2_+1.1 post-stress LVEF 0.394-0.13 0.594-0.12 [ 0.37_+0.14 Soft Events 33% (7 pts) 5% (1 pts)* I 45% (9 pts) (*p=&O05 vs GroupA and GroupC) Fifty-nine pts (63%) had high SSS. Of interest we identified 3 groups: pts with high SSS, high SRS and low LVEF(Group A), pts with high SSS, low SRS and normal LVEF (Group8) and pts with high SSS, low SRS and low LVEF (Group C). Group A with multiple reversible perfusion defects and left ventricular systolic dysfunction is consistent with large amount of ischemia still present at time of acquisition. Group B presents both muttiple fixed perfusion defects with normal left ventricular systolic function which instead was abnormal in Group C. At the follow up Group A and Group C presented higher percentage of soft events than Group B (p=O.O05). Conclusion. In pts early after AMI the g-SPECT myocardial scintigraphy allows the identification of subgroups at high risk of soft cardiac events. LVEF add important informations over perfusion identifying the viable myocardium which needs to he revascularized.

Hokkaido University School of Medicine, Sapporo, Japan. Quantitative myocardial gated SPECT (QGS) has been validated for accurate measurement of LVEF. However, segmental wall motion (WM) or thickening (WT) processed by QGS werenot fully analyzed in relation to LVEF. Weevaluated the relationship between LVEF and segmental WM or WT score. Myocardial gated SPECT was performed in 44 patients with coronary artery disease 1 hr following administration of 600MBq of Tc-99m MIBI at rest. 3D surface images, splash images and global LVEF were automatically processed by QGS software. LV were divided into 5 segments; anterior (Ant), septal (Sep), apical (Ap), inferior (Inf) and lateral wall (Lat). WM by cine 3D surface images and w r by cine splash images were scored visually as 5 point grading system (0 as normal to 4 as akinesis or no wall thickening) by six observers to calculate mean regional WM and WT scores. The individual and summed scores were compared with global EF by linear regression. The correlation coefficients were: Seg Ant Sep Ap lnf Lat Sum WM 0.61 0.60 0.66 0.71 0.61 0.83 WT 0.42 0.44 0.46 0.59 0.44 0.74 Significant correlation was observed between global LVEF and individual as well as summed regional functions. LVEF correlated better with WM than WT. Among regional parameters, wall motion in inferior and apical regions contributes stronger impact on global LV function.

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23.32

LOW-DOSE DOBUTAM1NE GATED SPECT; IMPROVEMENT OF REGIONAL FUNCTION 1N ACCORDANCE WITH GLOBAL CHANGES FOR VIABILITY ASSESSMENT D.S. Lee, S.T. Lira, G.J. Cheon, M.M. Lee, J.-K. Chung, M.C. Lee. Seoul National University, Seoul, Korea

TC-99M SESTAMIBI GATED SPECT IN SUBENDOCARDIAL INFARCTION AND MYOCARDIAL STUNNING. BB Chin, D Kraitchman, I Oznur. Johns Hopkins Medical Institutions, Baltimore, MD, USA The purpose of this study is characterize myocardial function and perfusion defect severity in canine models of stunning and subendocardial infarction (sMI) at rest and after dobutarnine. Eight dogs were studied. Group A were controls. Group B sMIs were made by 90 min LAD cath occlusion and reflow. Group C stunning was produced by partial LAD occlusion and reflow. Sestamibi (0.75-1.0 mCi/kg) injections were at rest after reflow. SPECT was acquired on a 3-detector system (8 bins/beat). Bullseye plots quantified severity. Systolic wall thickening index (SWI)=[end systole-end diastole]/end systole* 100. Wall motion was validated by MRI with fast SPGR, ECG-gated tagging. ]q~C delineated viability. Extent of wall motion abnormalities was greater than TTC infarct size. In group C (no infarct by TTC), distal anterior hypokinesis at rest markedly improved with dobutamine (5gg/kg/min). Dog anterior SWI defect baseline dobutamine change A1 none 18% 37% lt% A2 none 20% 29% 9% A3 none 23% 37% i4% B1 mild-mod 15% 28% 13% B2 mild-mod 4% 20% 16% B3 mild meal -2% 2% 4% C1 mild~mod 3% 34% 31% C2 mild-meal -6% 30% 36% Small subendocardial infarctions and stunning produced mildmoderate defects in ungated and end-diastolic images. Preliminary results show the magnitude of improvement in SWI was greater for stunned myocardium compared to subendocardial infarction.

We examined whether regional changes of dysfunctional myocardium were represented by global changes during dobutamine infusion in gated myocardial SPECT. Lowdose dobutamine (5 },tg/kg/min) myocardial SPECT was performed after rest T1-201/gated Tc-99m MIBI dipyridamole stress SPECT in 22 patients with coronary artery disease. Endsystolic elastance (Emax), enddiastolic volume and blood pressure were measured using Cedars QGS and arterial tonometry. Perfusion (0 to 3: normal to defect), wall motion (0 to 4: normal to dyskinesia) and wall thickening (0 to 3: normal to absent) were graded visually. Changes of global parameters were used to predict improvement of regional wall thickening by discriminant analysis. Among 374 segments, 87 were dysfunctional with persistent or partially reversible perfusion defect. Ejection fraction (EF) and Emax improved significantly in the patients having improved regional function (group I) and having not (group II). Enddiastolic and endsystolic volumes decreased and blood pressure increased in group I but not in group II. EF was the only discriminant parameter to predict improvement of wall thickening during dobutamine infusion. We concluded that improvement of walt thickening of dysfunctional myocardium was represented in the increase of EF during dubutamine infusion.

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23.33 WALL MOTION AND THICKENING: ANALOGY & DISPARITY A QUANTITATIVE GATED SPECT STUDY USING *gmTcM1BI. MB Imran, K Morita, I Adachi, M Konno, N Kubo, -i" Moehizuki, N Tamaki.

Hokkaido University School of Medicine, Sapporo. Japan. Purpose of this study was to compare segmental wall motion

T U E S D A Y A IVI A P R I L 20

(WM) and walt thickening (wr), and to evaluate their divergence in patients with coronary artery disease (CAD). Methods: A total of 44 patients with CAD were included in this study. A resting gated SPECT study was performed one hour after an injection of Tc-99m MIBI. Commercially available QGS software was used to generate 3D surface display and splash images. Left ventricle was divided into 9 segments. Each segment was evaluated by 6 independent observers, and WM and WT were scored from 0 (no abnormality) to 4 (severe abnormality). Finally the averaged scores for each segment were used to compare WM with WT by correlation analysis and paired ' t' test. Results: There was fairly good correlation between WM and WT of individual segments (r =0.62, p<0.00Ol) and no significant difference between mean scores of WM (0.79_+0.96) and W]" (0.80+0.84) was found (p=ns). However, data scatter was observed on the higher WM scores. Greater WM abnormalities (WM-WT>2) were seen more often in septal regions (10/12) despite normal stress/rest perfnsion. Among septal regions such discordance was commonly observed in post-CABG patients (25% in post-CABG vs 8% without CABG). Cnndusion: Segmental wall motion and wall thickening showed similarity on QGS studies. However septal functions should be carefully evaluated especially in postCABG patients showing WM abnormalities even when perfusion and WT is normal.

Journal of Nuclear Cardiology January/February 1999, Part 2

23.35 DETERMINATION OF THE SIGNIFICANT AMOUNT OF VIABLE MYOCARDIUM IN PATIENTS WITH LEFT VENTRICULAR DYSFUNCTION. M. Gartcheva -Tzatcheva, St. Milanov. Faculty of Medicine - Sofia, Bulgaria The aim of the study was to evaluate Rest-Nitrate Tc 99m sestamibi (RNTc) planar examination with nitrate radionuclide angiography (N RNA) for identification of the significant amount of viable myocardium, related to improvement in left ventricular ejection fraction (LVEF). Fifteen pts with left ventricular dysfunction (LVEF 31% _+9%) after myocardial infarction were studied with RNTc and NRNA before revascularisation. In RNTc following rest (1 hr) study 10 mg isosorbide dinitrate p.o. was administered and the study was repeated after 3 hrs. The perfusion defects with -> 50% uptake on the rest or nitrate study were considered to represent viable myocardium. Left ventricle was divided into 15 sgts. The vitality score (VS) represented the part of viable sgts from all sgts with reduced _<80% tracer activity. NRNA was performed in a separate day with Tc 99m RBC. After a basal RNA a Perlinganit infusion (0.1 mg/min) was done and the NRNA was obtained at the 15" minute. The total LVEF from basal and NRNA was determined. An improvement of _>3%was considered significant. The pts with significant improvement of LVEF had a VS 0.77 + 0.20, n = 6, while pts without significant improvement had score 0.19 + 0.13, n = 9, p < 0.001. All pts with VS _>0.5 had an LVEF significant improvement. The size of the irreversible defect (StD) was _<3 sgts in pts with LVEF significant improvement (1.3 + 1.1, n = 6) and > 3 sgts in pts without (5.7 + 1.7, n = 9, p < 0.001). In conclusion SID _<3 sgts and VS >_0.5 identified pts with significant amount of viable mvocardium.

23.34

23.36

GATED MYOCARDIAL PERFUSION SPECT FUNCTIONAL PARAMETERS PREDICT FUNCTIONAL RECOVER AFTER PTCA E.G. DePuey, S. Dorbala, M. Kamran, K. Shahzad, H. Salensky, K. Nichols,S. Yao, A. Rozanski. St. Luke's-Roosevelt Hospital and Columbia Univiversity, New York, NY, USA

RELATION BETWEEN Tc-99m FURIFOSMIN MYOCARDIAL UPTAKE AND THALLIUM-20I ACTIVITY IN PATIENTS WITH CHRONIC ISCHEMIC LEFT VENTRICULAR DYSFUNCTION. A. Cuocolo, G. Rubini, W. Acampa, E. Nicolai, L. Florimonte, G. Storto, G. Di Giovine, A. D'Addabbo, M. Salvatore. University Federico 11, Napoli, Italy. The role of Tc-99m furifosmin in the identification of dysfunctional but viable myocardium has been not yet defined. This study was designed to compare the results of furifosmin SPECT with those of thallium-201 in the same patients with ischemic left ventricular (LV) dysfunction. Twenty-one patients with documented coronary artery disease and LV dysfunction (ejection fi'action 34±8%) underwent on the same day rest-redistribution thallium and resting furifosmin SPECT. Tracers uptake was quantitatively measured in 22 segments/patient. LV function was assessed by echocardiography in corresponding segments. In all segments, a significant relationship between furifosmin and rest-redistribution thallium activity was observed (r=-.86 and r=-.90, respectively, both p<.0001). Of the 462 total segments, 194 (42%)had normal function, 116 (25%) were hypokinetic, and 152 (33%) a-dyskinetic. No difference between furifosmin and thallium uptake was observed in normal, hypokinetic, and a-dyskinetic segments. Of the 152 a-dyskinetic segments, 87 (58%) showed moderate reduction (>50% of peak) and 65 (43%) severe reduction (<50%) of thallium uptake. Furl fosmin uptake was lower in a-dyskinetic segments with severe reduction of thallium activity as compared to those with moderate reduction (37±16% vs 69+13%, p<.001). These results suggest that furifosmin cardiac tomography may be useful in the identification ol' dysfunctional but still viable myocardium in patients with chronic coronary artery disease.

To identify the ability of gated Tc-99m sestamibi myocardial perfusion SPECT to predict recoverability of regional and global LV fimction following coronary revascularization, 57 patients (pts) underwent rest/gated post-stress SPECT before and 14 _+ 11 weeks following PTCA of total of 69 major vascular territories (VTs). Potential predictors of recoverable function evaluated included: resting defect extent*, severity*, and defect/normal count density ratio*; the degree of stress-induced ischemia*; LVEF*; regional wall motion (WM)**and thickening (WT)**; and % angiographic stenoisis *** (*=quatitative, **=semiquantitative, ***=visual analysis). Of the 57 pts, 22 (39%) increased LVEF >_5 points after PTCA. Of the 69 VTs, 37 (54%) improved regional WM. By stepwise multiple linear regression analysis, the only significant predictors of improvement in WM were pre-PTCA WM (p<.001) and WT (p<.0001). Only pre-PTCA LVEF (p=.037) predicted an increase in LVEF. We conclude that gated SPECT functional parameters are useful to identify viable myocardium and predict functional recovery after PTCA.

Journal of Nuclear Cardiology Volume 6, Number 1, Part 2

Abstracts Tuesday morning, April 20, 1999

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23.39

MYOCARDIAL UPTAKE OF Z°ITHALLIUM (TI), 99MTcSESTAMIBI (MIBI) AND 99~tTC-TETROFOSMIN (TF) IN HYPOKINETICSEGMENTSAFTER AMI Bruno A., ~ M, *Finzi A, *Cali G., Long~ V . , ~ P. DeptofNuclMedand *Cardiology,IRCCS4)sp.Maggiore,Milan-Italy

DETECTION OF MYOCARDIAL PERFUSION REVERSIBILITY BY REST-NITROGLYCERIN 99MTCMIBI. COMPARISON WITH 2°ITL REINJECTION. J.F.Batista, O.Pereztol, J.A.Vald6s, E.Sfinchez, R.Stusser, L.M.Rochela, D.Ldpez. CIC, Havana, Cuba.

~ se#~,~ re~e~t a mt mglioUe ~ q x r t ~ of v i ~ ~ ana ~ ~ of ~ ve,~m a ~ ~0overy(WMR)of e,ese segnen~ is ~ Di~erentt ~ e v ~ ~ TF ard MIBI~ve Ix~ prcgxea to p ~ c t ee WMR~ ~ The aim of ~ sway wasto¢xaNz~'ein 17~ witha reoer~AMI(272c d x ~ t ~ ~ ) the , ~ el'IF, MIBIard TI uplakeof 71 ~ seglne~ (4~Aof l~d segner~ wi~ ~mnml l~esis). All ~ ~ TI ~ TF and MIBI SI~LT beforeand ba~ ~t~obeforeand a~er ~ Fotly-fixoflhe 71 ~ segnm~ did n~timt:~r~lheirkine~ on echo lX~tm g ~ amUd The uOate ,~fluesof fl~se segm~ ~ e obmimtby raeam of a ~ arolysisef tl~ l:x~armapsbasedon a lO-level mlourstile.

This study aimed to test whether sublingual administration of nitroglycerin (NTG) could improve the capability of 99mTc-MIBI to detect myocardial perfusion reversibility comparing it with thallium reijection imaging in the same group of patients. Thirty eight patients (33 men, 5 women, mean age (49.3 _+ 8.2 years) with previous myocardial infarction (mean evolution 7.1 + 3.9 months) were submitted to exercise, redistribution and reinjection 2°lTt imaging, and exercise, rest and NTG MIBI myocardial scintigraphy. The observed agreement on reversibility detection between NTG MIBI and 2°1T1reinjection in 210 coincident segments with perfusion defects used for this analysis was 78% with a significant kappa=.56 _+ .07 standard error of kappa. Overall observed agreement for detecting normal or abnormal segmental uptake was 89%, with a significant kappa=.78 +_.04 standard error of kappa. Our data suggest that the use of a NTG MIBI protocol results in an improvement for detecting exercise-induced perfusion defect reversibility, and achieves similar results to those from a 2°iT1 reinjection protocol.

slw_crtlaake TJ(nmW~SD). TF (mean~D). M ~ (rnean~D).

r

(r~-253 72,0-!-_18.3 68.0+_20.2 62.5-Z-_l&9

~ (n~46) 65.7+15,0 57.6+._15.9 57.1+_15.5

p

rts, 0.01 rts.

Theseresultsshowthata ~ ~ in TFuptakeexistsin scgm~ withar,d wi~out~ ~WMP,, andmgg~tt~ ~ urta~ ~Jdics maybe l r ~ in s~pam~ ~ scgn~gs with ~ or t~lllyrecro~ ~ .

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23.40

PREDICTION OF FUNCTIONAL RECOVERY AFTER REVASCULARIZATION WITH TI-201 SPECT AND 99mTc-MIBI GSPECT Dziuk M., Cholewa M., Borkowski D., Kwiatkowski W Central Clinical Hospital WAM, Warsaw, Poland The aim of the study was to evaluate the myocardial perfusion scintigraphy with T1-201 (rest-redistribution SPECT) and gated perfusion scintigraphy with 99mTc MIBI (GSPECT) in the assessment of viability and prediction of functional recovery. Materials and methods: 32 patients were examined before and 3 months after revascularization. Asynergic territory viability was estimated semiquantitatively in 16 segments of the left ventricle (LV) by cutoff 80% o f the maximal tracer uptake and/or preserved thickening in GSPECT study. Improvement of LV contractility in echocardiography after revascularization was used to prove segmental viability. Results: In the group of 32 patients 110 dyssynergic segments were observed before and after revascularization. In 81 viable segments revascularization caused the improvement of LV regional function in 71 segments. In the 29 non-viable segments before revascularization, the contractility improved only in 3 segments. The sensitivity and specificity of prediction of functional recovery were 96% and 72% respectively. Conclusion: The combination of T1-201 rest-redistribution SPECT and 9~Tc MIBI GSPECT studies is an effective method of prediction of LV functional recovery.

DIPYRIDAMOLE INDUCED STUNNING CONTINUES FOR AT LEAST ONE HOUR IN PATIENTS WITH CORONARY ARTERY DISEASE: EVALUATION WITH QUANTITATIVE GATED SPECT Y. Arai, S. Mizuno, K. Ohsato, T. Murakami, I. Moriuchi, Y. Nio, B. Kaku, K. Ohe, T. Mabuchi, Y. Takahashi, M. Ohnaka, Fukui Cardiovascular Center, Fukui. Japan. The quantitative gated SPECT (QGS) software that has automatic edge detection algorithm of the left ventricle (LV), can calculate LV ejection fraction(EF). To clarlify the significance of post dipyridamole-stress EF, we examined %EF change ratio ((poststress EF-rest EF)/rest EF). EF was calculated from dipyridamole-stress TC-99mTetrofosmin QGS in 63 patients (43 males, 61+11 years). Patients were grouped as follows based on coronary arteriography: No stenotic lesions (GO, n=18), 1 vessel disease (G1, n=21), 2 vessel disease (G2, n=16), 3 vessel disease (63, n=8). 7.6GO.1+13 G1 G2 G3 %EF change ratio -6.1_+9.2 -6.4+-6.4 -7.1 .+10.8 %EF change ratio of G1, G2, and G3 were significantly lower than that of GO (p<0.001 for each). These results indicate that effect of dipyridamole-stress induced ischemia on LV function (stunning) continues for at least one hour in patients with coronary artery disease.

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Abstracts Tuesday morning, April 20, 1999

23.41 REST MIBI-SPECT CONFIDENCE IN MYOCARDIAL VIABILITY: LATE FOLLOW UP V. Aria, A. Sandrin, G. Sanz, C. Balestrini, E. Conci, F. Zelaya, A. Canestri, V. Balestrini. Instituto Modelo de Cardiologia - C6rdoba - Argentina. Objective: Utility of rest MIBI as a marker of celular viability, functional evaluation and survival in patients (p) with severe coronary disfunctional contraction (SDC). Material and Methods: 43 p with SDC, age X=59, male 95%. EF < 30%, all prior MI, CHF 65%, angina 35%. Groups (G) GI: revascularized (RVC) 20 p. GII: without RVC 23 p. Baseline Evaluation: a) Radioisotopic angiogram: wall motion and EF. b) Rest MIBI' % regional uptake (% RU), % of necrosis (% NC). Follow up (FU) Radioisotopic angiogram and rest MIBI. Results: Basal: EF: GI 21.6%; GII 20.4% (p:ns). "% NC": GI 22.7, GII 38.7 (p=0.0001). "FU": G.._[a) EF: 6 month (mo) 28.7, 12 mo 28.3, 24 mo 29.5 all p<0.02 vs basal EF. b) % of segments with SDC: basal 63%, 6 mo 29% (p<0.0001). c) "Variation of %RU" in segments with $DC basal; basal' 78%, 6 m o 79% (p:ns). d) Survival: 24 mo 85%, deaths 1 during surgery, 2 p pre-discharge. GI__./Ia) EF: 12 mo 19.5 (p:ns) vs basal EF. b) Survival: 24 mo 82%, deaths: 4,9,10 and 11 mo; 1 p without information. Conclusions: 1) The RVC p increased EF and decreased the n° of segments with SDC. 2) The segments with SDC that improved motion after RVC no modified "% RU", supporting the MIBI confidence as celular viability marker. 3) Deaths on GI were related with in-hospital period.

23.42 PREDICTION OF FUNCTIONAL RECOVERY A F T E R REVASCULARIZATION: COMPARISON OF LOW-DOSE DOBUTAMINE Tc-99m SESTAMIB1 SPECT W I T H R E S T S P E C T AND DOBUTAMINE ECHOCARDIOGRAPHY. M Leoncini, *G. Marcucci, *M. Silvestri, A. Traini, D. Mondanelli, *A. Arena, *C. De Gaudio, L. Bardazzi, T. Giovannini, F. Frascarelli, A. Petrella, *A. Mennuti. Division of Cardiology and *Nuclear Medicine, Prato Hospital, Italy. Low-dose dobutamine (LDD) increases blood flow to viable myocardium and improves Tc-99m sestamibi uptake. To compare LDD-SPECT with REST-SPECT and dobutamine echocardiography (LDDE) for prediction of functional recovery, 25 patients with chronic CAD and regional dysfunction scheduled for revascularization were studied. All patients underwent Tc-99m sestamibi SPECT under baseline condition and, on separate day, LDDE and SPECT with tracer injected during LDD infusion (10mcg/kg/min). Resting echocardiography was repeated after revascularization. Regional tracer uptake (grading from 0=normal to 4=absent) and wall motion (grading from l=normal to 4=dyskinesia) were evaluated in the same 16 myocardial segments. Left ventricle was divided into three vascular territories. Viability was defined by < 2 uptake in > 50% of asynergic segments/territory. Results: 34 asynergic regions were considered; at follow-up, 21 territories were defined viable and 13 fibrotic. REST-SPECT LDD-SPECT LDDE Sensitivity 67% 90% 81% Specificity 69% 85% 77% Accuracy 68% p<0.05 88% 79% Conclusions: for prediction of functional recovery after revascularization, LDD Tc-99m-sestamibi SPECT provides better accuracy than REST-SPECT and is comparable with LDDE.

Journal of Nuclear Cardiology January/February 1999, Part 2

23.43 EVALUATING SALVAGED MYOCARDIUM OF A C U T E M Y O C A R D I A L INFARCTION USING T c - 9 9 m T E T R O F O S M I N A N D 1-123 BMIPP IMAGINGS. T.Toyama, H.Hoshizaki, N.Isobe,

N.Takama, N.Koitahashi, M.Suguta, M.Nakatsugawa, T.Hiroi, H.Tada, H.Adachi, S.Naito, A.Nogami, S.Oshima and K.Taniguchi. Gunma Prefectural Cardiovascular Center, Maebashi, Japan. To evaluate salvaged myocardium of acute myocardial infarction (AMI), we performed rest Tc-99m-Tetrofosmin (TF) and 1-123 betamethylpentadecanoic acid (BMIPP) SPFEF and rest Tl and Tc-pyrophosphate (PYP) dual SPECT in 25 initial AMI patients within 10 days after admission, who all were reperfused successfully. TF and BMIPP SPECT images were obtained at 15 minutes after tracer injection and 3 to 5 months later (F-up). Left ventriculograpyhy (LVG) was done within 3 weeks after admission and at 3 to 5 months later, SPECT image was divided into 20 segments and regional tracer uptake was scored by using a 4-point scoring system (DS; 0 = normal to 3 = defect ), and summed to a defect score (RDS) and calculated the number of reduced uptake segments (ES) of each infarcted area. The inlhrcted area was defined as the Tc-PYPuptake area (ES). LVG was divided7 segments andwall motion was estimated by using a 6 point grading system (WMS; -1 = dyskinesis to 4 = normal ). Uptake (+) and (-) were definedas DS~2 andDS=3, respectively. WMS was comparedin the 52 infarcted LVG segments of 18 patients without restenosis, which were classified into 3 subgroups of TF(+) and BM1PP (+), TF(+) and BMIPP() ,and TF(-) and BMIPP (-). 1. The ES and RDS in different imagings. (*:p<0.05 and **: p<0.01 vs Tc-PYP, #;p<0.05 vs BMIPP, $; p<0.05 vs F-up, &;p<0.05 vs TI) Tc-PYP T1 TF F-upTF ] BMIPP I F-ut~BMIPP J IES I 7.1-+4.1 15.2~-3.3" 4.2±2.7"#$1 3.2_+2.9 6.5_+3.85 I 4.3_+2.8 ] RDS] 10_+8,5 8_+6.7#& 6.9_+7.4 14.3_+9.25 9.1_+7.4 The ES and RDS of TF were smaller than TI. The ES of BMIPP was near to that of Te-PYP. 2. The i nprovement of VMSin 3 sub I subacute chronic p FF(+) and BMIPP(+) (n=20) 2.3 ± 1.0 3.6 +0.7 < 0.0001 FF(+) and BMIPP(-) (n=20) 1.05-l.1 2.3±1.1 <0.0001 FF(-) and BMIPP(-) (n=12) 0.3 ±0.9 0.9± 1.0 < 0.05 Combination of TF and BMIPP is useful to evaluate salvaged myocardium and predict improvement of walI motion in patients with AMI.

23.44 99mTc-SESTAMIBI AND 99mTc-TETROFOSMIN REST SCINTIGRAPHY FOR THE IDENTIFICATION OF VIABLE MYOCARDIUM: A COMPARISONWITH 201T1 REST-REDISTRIBUTION IMAGES. C.Cittanti, P.Colamussi, M.Giganti, A.Dafermou D.Barbieri, D.Mele, E.Ricci, A.Piffanelli. University of Ferrara, Italy. In patients with chronic coronary artery disease (CAD) and left ventricular disfunction (LVD) the extent of myocardial viability is a major clinical issue in deciding to proceed or not with revascularization. Aim of this study was to evaluate, in the same patient, the ability of standard lhr rest 99mTc-Sestamibi (MI) and 991nTcTetrofosmin (TF) imaging to identify myocardial viability in comparison with 201Tl-chloride (TL) rest-redistribution stu&es, without use of modified protocols like delayed images, nitrate administration. or slow-infusion tecniques Eighteen paUents (288 se,~ments~ all with clinical and instrfimental~evidenc'e of CAD and ~VD (mean LVEF=31%), underwent TL myocardial SPECT with rest-redistribution protocol and MI and TF rest SPECT studies. A segment evaluated as akinetic or diskinetic by conventional 16 segments echocardiography was considered "viable" if it showed evide~nce of redistribution or over 50% of peak activity (PA) in the delayed TL scintigraphic images and over 50% of PA in MI and TF rest studies. While high concordance values among the tracers were seen for normal and necrotic segments, the analysis carried out in the subgrou~ of segments matching TL scinugraphy viability criteria showed lower concordance data (see table). In the same subgroup of segments, correlation analysis of tracer uptake values amon~ TL redistribution and 99roTe-tracers images, showed the folldwin~ regression data: TLvsMI:r=0.66, TLvsTF:r=0.63, MIvsTF:r=0.96. ffa conclusion, on the basis of defect reversibility and 50% PA, rest MI and TF images seem to likewise underestimate viable myocardium extension in comparison with TL rest-redistribution images. Segment classification Normal Viable Necrotic

Thallium N° 96 67 125

No 98 52 138

Sestamibi Concordance 92 (96%) 48 (72%) 117 (94%)

Tetrofosmin No Concordance 95 90 (95%) 49 44 (66%) 144 119 (95%)

Journal of Nuclear Cardiology Volume 6, Number 1, Part 2

23.45

Abstracts Tuesday morning, April 20, 1999

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23.47

SALUTARY EFFECT OF ADJUNCTIVE NICORANDIL ADMINISTRATION ON SALVAGED MYOCARDIAL PERFUSION AND FATTY ACID METABOLISM -USING Tc-99m-TETROFOSMIN AND 1-123-BMIPP IMAGING *R. Seki, T. Toyama, N. Isobe, H. Hoshizaki, S. Oshima, K Taniguchi and *R, Nagai. *Gunma University School of Medicine and Gunma Prefectural cardiovascular Center, Maebashi, Japan.

201-THALLIUM UPTAKE AT REST TO PREDICT MYOCARDIAL VIABILITY ? A P R O S P E C T I V E STUDY USING QUANTITATIVE ANALYSIS OF W A L L MOTION RECOVERY. E. Ostwald, G. Schulz, K-Ch. Koch*, J. vom Dahl*, E, Klcinhans, U. Buell. Dpts. of Nuclear and *Internal Medicine I, RWTH Aachen, Germany

This study was designed to assess the cardioprotective effect of nicorandil (NCR), a potassium channel opener, in preventing repeffusion injury in acute myocardial infarction (AM[l). Methods. Thirty two patients were treated with NCR and nitroglycerin (groupA; n=12) or nitroglycerin only (group B; n=20) concomitant with reperfusion therapy of AMI. NCR was administered intravenously (4rag) before, intracoronaiy (2rag) just after reperfusion, and followed by continuous infusion of 4mg/h for 24 hours with nitroglycerin (1.5rag/h) infusion. We performed rest Tc-99m-tetrofosmin (TF), I- 123-/3 -methyl iodopheny[ pentadecanoic acid (BMIPP), and Tc-99m-pyropbosphate (PYP)SPECI" within 10 days, andleft ventficulograpby at 1 month after admission. In 20 segments of SPECT image, we used a 4-point tracer uptake-system (0--defect to 3=normal), and summed to a uptake score (RUS), and defined the infarcted area as the number of the Tc-PYP uptake segments (ES). We calculated the percentage of salvaged myocardial perfusion (%MP) from {RUS(TF)/(ES×3)}× 100, and the percentage of salvaged myocardial fatty acid metabolism (%FAM) from {RUS(BMIPP)/(ES × 3)})< 100. Results. l)There were no differences between two groups in age, gender, time to reperfusion (A;4.9 ± 4.5hrs vs B;3.9-----2.8hrs), peak CPK (A;2125 ± 184 vs B;2456± 1300)and left ventricular ejection fraction (A;60±5% vs B;60±10%), 2)The %MP was significantly higher in group A (A;77 ± 18% vs B;55 ±28%, p/~0.05). The %FAM tendedto be higher in group A (A;4I ±11% vs B;25+22%, p=0.07). Conclusion. NCR administration seems to be a useful adjunctive therapy to salve myocardium following successful coronary repeffusion in patients with AMI.

Criteria of 20I-Thallium-Chlorid (2°1T1) SPECT to estimate myocardial viability are controverse. This study searchs for regional quantitative thresholds to predict functional recovery as the ultimative target of revascularisation (RV). Study included 32 pts with advanced CAD, previous infarction and severe wall motion abnormalities in LAD-territory, who underwent RV independently of the 2°1T1 viability interpretation and a second angiography 3 _+1 mo after RV. In RAO levocardiography wall motion was analysed both visually and by the centerline method, expressed as standard deviations from the reference (RWM) compressed to 5 segments. SPECT was acquired 15 min and 3 h after rest injection of 100 MBq T12°1 and both were regionaly normalised to individual maximum at 15 min pi, expressed as percentage uptake. Extracted were 32 pts with successful RV of LAD. Before RV 29 of 64 anterior and apical segments revealed an akinesia. Reciever operator characteristic of 2°~T1 uptake to predict recovery demonstrated an optimal threshold at <°50% uptake with a npV of 1,0, a ppV of 0,68 and an accuracy of 0.79. At the >_70% uptake threshold a ppV of 1.0, a npV 0.70 and an accuracy of 0.76 was estimated. In conclusion, a rest 2°IT1 uptake 3 h pi <50% indicates scar and an uptake _>70% indicates viable myocardinm in LAD territory. In the 50 to 70 percentage range 2°aT1 uptake can not predict functional recovery sufficiently.

23.46

23.48

MYOCARDIAL VIABILITY ASSESSED BY NON-TRANSMISSIVE ATTENUATION AND SCATTER CORRECTED 99'~Tc-MIBI SPECT AT REST COMPARED TO ISF-FDG PET. G. Sehulz, E.R. Schwarz*, E. Ostwald, K.Ch. Koch*, J. vom Dahl*, U. Buell. Dpts. of Nuclear and *Internal Medicine I, RWTH Aachen This study estimates the accuracy of viability diagnosis employing a non-transmissive triple energy window based attenuation and scatter correction method (ASC) for MIBI SPECT compared to FDG PET, in 128 patients with previous myocardial infarction, angiographicatly proven advanced coronary artery disease and severe abnormal wall motion. In the three data sets (MIBI SPECT with or without (NC) ASC and FDG PET) an automatical quantification procedure determined relative uptake values of 33 regions nolwnalised to perfusion maximum (MIBI 100%) for each patient. Regions with FDG uptake _>70% were defined as viable, 50 to 69% as intermediate and < 50% as scar. MIBI uptake > 50% was related to a positive predictive value (ppv) of 0.95 (ASC) or 0.94 (NC) for preserved viability, MIBI -> 70% to ppv of 0.98 (ASC) or 0.99 (NC). In regions with severely reduced MIBI uptake 20 - 49% the incidence of viable, intermediate and scared myocardium did not differ significantly independently of ASC wasor NC. In myocardial MIB1 uptake defects < 20% viability was absent with a npv of 0.80 (ASC) or'0.84 (NC). However, the number of detected regions with uptake <20% was significant higher using ASC (250 vs. 129). MIBI SPECT with or without ASC predicts myocardial viability in regions with uptake _>50% of the maximum. In regions with uptake of 20- 49% viability should be better estimated by FDG PET. In regions with MIBI <20% scar can be assumed, which is detected more frequently using ASC.

POSTNISOLDIPINE R A D I O N U C L I D E A N G I O G R A P H Y TO DETECT VIABLE MYOCARDIUM BEFORE PERCUTANEOUS TRANSLUMINAL CORONARY ANGIOPLASTY. A.Peix, L.Llerena, F.Ponce, A.L6pez, A.M.Maltas, D.GarciaBarreto. Institute o f Cardiology, Havana, Cuba. Myocardial viability determines prognosis in patients with prior myocardial infarction and poor ventricular function submitted to a percutaneous transluminal coronary angioplasty (PTCA). To detect viability in the infarcted zone, we used nisoldipine, a calcium channel blocker with selective coronary vasodilation. Twelve infarcted patients (mean age: 44 + 8 years; 11 men and 1 woman) were studied. Three radionuc]-ide angiography in 35 ° left anterior oblique, anterior and 70 ° lateral views were performed: at rest, one hour after 5 mg oral nisoldipine administration and one month after PTCA. O f the 46 segments with reduced contractility at rest, 27 improved both postnisoldipine and post PTCA, while 5 only did it after PTCA. The left ventricular ejection fraction increased from 48 + 8% to 53 + 9% postnisoldipine (p = 0,01) and to 53 + 10% post PTCA ~p=0,01). The peak filling rate and the systolic volume increased, but not significantly. The end-systolic volume decreased significantly from 131 + 25 ml to 116 + 14 ml postnisoldipine and to 118 + 19 ml post PTCA (p< 0,05). We conclude that the postnisol~pine radionuclide angiography is a useful method to detect myocardial viability and predict post PTCA functional recovery,

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~,bstracts Tuesday morning, April 20, 1999

23.49 COMPARISON OF REST TECHNETIUM-99M TETROFOSMIN (TN) IMAGING WITH RESTREDISTRIBUTION (RRD) TL-201 FOR THE ASSESSMENT OF MYOCARDIAL VIABILITY G. Kahraman, V. Sansoy, Z. Yigit, C. Heper, D. Giizelsoy. Institute of Cardiology, University of Istanbul, Istanbul, Turkey The purpose of the study was to compare the regional myocardial tracer distributions between rest TN and RRD T1201 images in patients with coronary artery disease (CAD) and severe left ventricular dysfunction. Thirty-one patients (all men, mean age 59±9) with CAD were included in the study. All patients underwent RRD TI-201 SPECT and rest TN SPECT imaging. In the 26 segment model used, 806 segments of 31 patients were compared by quantitative analysis. Twenty-six percent of defects on initial T1-201 imaging showed RD. Mild defects were detected in 44%, 44% and 42 % of segments, severe defects in 22%, 21%, 32% by initial TI-201, RD T1-201 and TN imaging respectively. The average uptakes in segments with TI-201 RD for initial TI-201, delayed TI-201 and TN were found to be 49%, 60% and 54% (p< 0.002) and in segments without RD 56%, 57% and 51% (p< 0.02) respectively. The uptake on TN imaging was found to be significantly less than RD T1-201 imaging in segments with reduced uptake, however further research is needed to see the clinical implications & t h i s slight though significant difference.

Journal of Nuclear Cardiology January/February 1999, Part 2

23.51 SIGNAL AVERAGING ECG AND 201 THALL1UM RE,ST/RED SPET STUDY IN TttE IDENTIFICATION OF MYOCARDIAL VIABILITY IN ANTERIOR MYOCARDIALINFARCTION.

Di Leo C, Bestetti A, Tagliabue L, Del Sole A, *Tarricone D, *Fiorentini C, Yarolo G.L. Nuclear Medicine Department, *Cardiology Division. University of Milano, HSPaoto; Milan (Italy) To evaluate the relationship between myocardial viability (MV) assessed by 201Tt rest/red protocol and ventricular late potentials (VLPs), we studied 25 pts (age 57 +_ 10 yrs) with a first prior anterior AMI. All pts, were studied by signal averaged ECG, using conventional time domain parameters (QRSD > 120 ms, LAS40 > 30 ms, RMS40 > 25 gV), within 48 hrs after onset of AMI and on the day of discharge ( 17 _+ I1 days). 201-T1 rest/red SPET study was performed 18 _+ 8 days after AMI. A 16 segments model was used for quantitative analysis. MV was identified in presence of a mild defect (cts > 60 % of max) or a defect of any severity with a reversibility more than _> 15 % on delayed images. Pts were divide into 2 groups: presence of MV, at least 1/3 of segments appear to be viable (Gr. 1 n=16) and absence of MV (Gr. 2 n=9). Results: pts with MV (Gr. 1) compared with those without MV (Gr. 2), show a longer QRSD (104.7 ms vs 93.2 ms; p<0.005) and LAS40 (30.4 ms vs 18.4 ms; p<0.005), measured on the day of discharge. QRSD and LAS40 values were not different in both groups after onset of AMI (103.7 ms vs 100 and 32.3 ms vs 26; p=ns). Conclusion: VLPs are detectable almost always in periinfarctual viable myocardium, that colud be the originating electrically abnormal substratum at risk for further cardiac events.

23.50

23.52

CAN ANALYSIS OF THALLIUM WASHOUT RATE FROM STRESS TO REDISTRIBUTION IMAGES OBVIATE THE NEED FOR REINJECTION IMAGES? Anastasia N. Kitsiou z'2, Athanasios Theodorakos 2, Dimitrios Fasitsas2, Christodoulos Stefanadis ~, Pavlos K. Toutouzas 1. 1Cardiology Department, Athens University; 2Athens Cardiology Center, Athens, Greece

ENHANCED DETECTION OF VIABLE MYOCARDIUM BY TECHNETIUM-99M- TETROFOSMIN IMAGING AFTER NISOLDIPINE ADMINISTRATION.

Thallium reinjection may help in the identification of viable myocardium. However, it has been suggested that analysis of thallium (T1) washout rate (WR) from stress (S) to redistribution (RD) images can predict the thallium defects that will become reversible after reinjection (RI), obviating, thus, the need for RI imaging. In this study, we investigated the T1 washout patterns in irreversible defects on RD images and examined the fate of these defects on RI images in terms of reversibility. Twenty-five patients (22 men) with known CAD (mean age 60+9 years) underwent S-RD-RI T1 SPECT. Three short-axis slices (apical, mid, and basal) and one mid-ventricular vertical long slice were visually assessed per patient. WR was defined as (counts on S images minus counts on RE) images)/counts on S images, within the defect. A total number of 71 irreversible defects were identified on RD images. Among them, 37 (52%) were reversible on RI images. WR in irreversible defects on RD that became reversible on RI was similar to the WR rate in irreversible defects on RD that remained irreversible on RI (34_+15% versus 31+17%, respectively, p=NS). Our findings suggest that analysis of T1 WR rate from S to RD images does not differentiate reversible from irreversible defects on RI images. Therefore, for assessment of myocardial viability, thallium reinjection provides valuable information.

A.Peix, A.L6pez, F.Ponce, L.Llerena, M.Castillo, A.Paredes, A.Ma.Maltas y D.Garcia-Barreto. Instituto de Cardiologfa y Cirugia Cardiovascular, Havana, Cuba. To assess if nisoldipine administration improves the imaging capabilities of Tc-99m-tetrofosmin scimigraphy in detecting viable myocardium, fifteen pre-revascularization patients with prior myocardial infarction and significant coronary stenosis, underwent two Tc-99m-tetrofosmin studies the same day: one at rest and the other after 5 mg oral nisoldipine administration. All patients were also studied by radionuclide angiography before and 2 months after coronary revascularization (either surgical or by angioplasty). On resting Te-99m-tetrofosmin study, 62 segments had normal uptake, 54 showed moderately reduced uptake and 19 had severely reduced uptake. O f these 19 segments, the 40% had increased uptake after nisoldipine (from 45+3% to 56 + 14% of peak activity, p=0,01). The 80% of segments with reversible Tc-99m-tetrofosmin defects and abnormal function showed functional recovery after revascularization, whereas 83% of segments with irreversible Te-99m-tetrofosmin defects did not. These data suggest that the nisoldipine-induced changes in Tc-99m-tetrofosmin perfusion imaging improves the detection ofhypoperfused but still viable myocardium in infarcted patients.