Sports Med 2007; 37 (4-5): 448-450 0112-1642/07/0004-0448/$44.95/0

CONFERENCE PAPER

© 2007 Adis Data Information BV. All rights reserved.

Marathon Cardiac Deaths The London Experience Dan S. Tunstall Pedoe London Marathon Medical Director 1981–2006, London, UK

Abstract

Data from the London Marathon, with 650 000 completed runs, show that cardiac arrests occur even in the most experienced runners. Although coronary artery disease was the commonest cause of sudden cardiac arrest (SCA) with five deaths and six resuscitations, hypertrophic cardiomyopathy or idiopathic left ventricular hypertrophy (HCM) was diagnosed at autopsy on three occasions. HCM deaths had the same average age as the runners with ischaemic heart disease who had SCA or sudden cardiac death. The cardiac arrests were at the finish in less than one-third of cases and the remainder occurred between 6 and 26 miles on the course. Only one of the eight runners who died had reported symptoms to his family or physician suggestive of cardiac disease. The runner who had reported pre-race angina pain was investigated with a negative exercise stress test prior to the marathon and despite this died with a left anterior descending coronary artery stenosis. The cardiac death rate for the London Marathon is 1 in 80 000 finishers.

In the 1976 New York Academy of Sciences Conference on the marathon, Bassler[1] proposed that marathon runners had immunity to atheromatous coronary artery disease. Unfortunately, this appears to be as mythical as Pheidippides running from Marathon to Athens and dying blissfully from a ruptured heart as he announced, “Rejoice! We conquer!” Collapse during and after marathon races is common, and although an uncommon cause, primary cardiac arrest from structural heart disease or cardiac arrhythmia must always be included in the differential diagnosis. Deaths are most frequently from sudden cardiac arrest (SCA) associated with structural heart disease and failed cardiac resuscitation. Although deaths in athletes <30 years old are rare, many causes of sudden cardiac death (SCD) have been reported, with hypertrophic cardiomyopathy (HCM) being the most frequent.[2] In older athletes, cardiac ischaemia (IHD) from atheromatous coronary artery disease is the most frequent cause and HCM is only occasionally reported despite the re-

ported prevalence of 0.2% in the general population.[2] Rather than reporting data from a variety of international sources, with very different populations of marathon runners and no autopsy data, this article will focus on the data from the 26 London Marathon races, with 650 000 completed runs, showing that cardiac arrests can occur in even the most experienced runners. The London Marathon was established in 1981 with 7000 runners and now has fields of 35 000 finishers. The age distribution is such that the most popular age groups are 35–40 years and 40–45 years. Women entries have gradually reached 31% of the field but comprise only about one-sixth of the cumulative total finishers. There have been no female deaths or cardiac arrests. Data on deaths and major medical problems are collected from the St John Ambulance Brigade and the hospitals receiving casualties. Contact was made with the coroner concerning all deaths and the autopsy was attended by the author for six cardiac deaths and by a colleague in the other two. Full post

London Marathon Cardiac Deaths

mortem reports (including histology) were received on seven of eight deaths. Data on five of six resuscitations is currently available. Although coronary artery disease was the commonest cause, with 11 SCA resulting in five deaths and six resuscitations, HCM or idiopathic left ventricular hypertrophy (LVH) was diagnosed at autopsy on three occasions. Runners with HCM deaths had the same average age as the runners who arrested with IHD. SCA occurred at the finish in less than one-third of cases and the remainder occurred between 6 and 26 miles on the course. Only one of eight runners who died had reported symptoms to his family or physician suggestive of cardiac disease. The runner who had reported pre-race angina pain symptoms had a negative exercise stress test 2 months prior to the marathon and despite this died with a left anterior descending coronary artery (LAD) stenosis. There were no deaths in the first 9 years of the race. Cardiac arrests with successful resuscitations occurred in 1983, 1988, 1990, 1997, 1998 and 2006. The first death occurred in 1990 and at autopsy was ascribed to HCM (but no histology report was subsequently received). There were two additional HCM deaths in 2001 and 2005. The death in 2005 was initially attributed to idiopathic LVH and was subsequently listed as HCM (i.e. severe, unexplained LVH) after one cardiac pathologist described fibre disarray, but this view was not shared by another. The remaining deaths in 1993, 1995, 1996, 1997 and 2003 were from IHD following cardiac arrest with unsuccessful resuscitation. Although the numbers are small, there was little difference in the average age of those who died from HCM (47 years old), those who died from IHD (49 years old) or those who were resuscitated (48 years old), nor in the average distance run before collapse by the HCM deaths (16 miles) and the IHD deaths (15.6 miles). 1. Cardiac Events in Experienced Runners One death from IHD occurred in a 47-year-old runner who was running his 38th marathon and another in a 52-year-old who was running his 11th marathon, was an ultra marathoner and was a member of the 100km association ultra running club. Of © 2007 Adis Data Information BV. All rights reserved.

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the cardiac resuscitations, three of six had run several marathons; the most recent arrest was in a 50-year-old who was running his 19th marathon and 10th London Marathon. He had an emergency angioplasty with stenting for a blocked LAD after a cardiac arrest with successful resuscitation at 20 miles. 2. Post Mortem Findings All eight hearts from the SCD casualties showed obvious cardiac pathology. Four of the IHD deaths had double or triple coronary artery vessel disease with evidence of previous myocardial infarction. One heart, from the runner who had pre-race angina with a negative exercise stress test, had LAD stenosis of moderate severity only. The three HCM deaths showed severe LVH with heavy hearts. One had debatable myocardial fibre disarray and could have been labelled idiopathic LVH or possible HCM. Another had obvious obstructive hypertrophic cardiomyopathy with fibre disarray and the third had no histology performed, but the experienced pathologist was certain that the diagnosis was HCM. 3. Discussion Cardiac-related marathon deaths have been calculated to occur between 1 in 50–100 000 runs.[3] In the London Marathon, apart from the cardiac deaths, there have been two fatal cases of subarachnoid haemorrhages whose initial symptoms occurred during or shortly after the run. The overall death rate for the London Marathon is therefore 1 in 65 000, with a rate of 1 in 80 000 for cardiac deaths. These death risks have been calculated on a time-of-exposure basis to be less than riding a motorcycle and about 3–4 times greater than riding a bicycle (in Europe) for the same length of time.[4,5] The individual risk is therefore very low and comparable to a large number of daily activities. Deaths associated with marathons have been reported from all over the world sometimes occurring in clusters as in the 2006 Los Angeles Marathon (two deaths) and in the 2006 Great North Run half marathon in Newcastle, England, (four deaths). This is a feature of a Poisson distribution, where an event that occurs rarely but has many opportunities to do Sports Med 2007; 37 (4-5)

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so, will occasionally occur in a small cluster after many years with no occurrences. 3.1 Practical Procedures

Protocols for cardiac arrest should be agreed upon by the volunteers and staff before the race. Although it is against the road racing rules, runners occasionally pass their race entry number to another runner, so the race number is not a reliable means of identification in all cases. The name and details of the dead runner should not be released until there has been formal identification by a relative or close friend, and the family has been informed and given permission to release the details. A runner who collapses is highly visible and the press may chase the story or be informed by people in the crowd, ambulance personnel, police or hospital staff. The runner who has a cardiac arrest may well not be certified dead until he reaches hospital. The British Press may use mobile phone scanners to listen into conversations and pretend to be a relative making legitimate hospital enquiries about the status of the runner. We block access to the ‘downed’ runner’s details on the marathon participant database and have no discussion of the event on mobile phones or radios, but rather use land lines or personal contact. Facilities should be available for the race medical director to meet with the relatives of seriously ill or deceased runners to break the news to them in a quiet and confidential environment. 3.2 Open Entry or Filtered Entry Through Medical Screening?

The philosophy of the London Marathon from its inception has been open entry with the runner under guidance from their own medical advisors and taking full responsibility for being fit and well on race day. We send all entrants medical advice, which outlines the risks and precautions.[6] To date, we have not taken the responsibility for excluding people on medical grounds. Many complete the marathon with what physicians would regard as serious medical problems.[7] Mass screenings of runners and verifying medical certificates of fitness to run, in 35 000 runners from all over the world is not practical.[3,4] The onus is on each runner to take responsibility for themselves and not for the race to initiate © 2007 Adis Data Information BV. All rights reserved.

any sort of entry filter, which is bound to be contentious, circumvented, inefficient and may render the marathon liable if the screening failed to prevent a case of SCD. 3.3 Should We Accept Marathon Deaths as Inevitable?

A marathon is not a health event, but training for the marathon promotes a healthy life style. Increasing numbers of high risk runners are entering marathon races and the question is whether, despite the higher risk of deaths while running a marathon, the overall trend is beneficial. For every marathon death, there may be thousands of runners who are postponing or preventing their heart disease. Completing a marathon is frequently the ultimate goal of a jogging-running programme. Prohibiting selected runners from competing and achieving this goal may prevent deaths during the marathon, but branding a generally safe activity more dangerous than it really is may be doing more harm than good.[5] Acknowledgements The author has indicated that he has no affiliation or financial interest in any organisation (other than the London Marathon) that may have a direct interest in the subject matter of this article.

References 1. Bassler TJ. Marathon running and immunity to atherosclerosis. In: Milvy P, editor. The marathon: physiological, medical, epidemiological, and psychological studies. Ann N Y Acad Sci 1977; 301: 579-92 2. Maron BJ. Sudden death in young athletes. N Engl J Med 2003; 349 (11): 1064-75 3. Maron BJ, Poliac LC, Roberts WO. Risk for sudden cardiac death associated with marathon running. J Am Coll Cardiol 1996; 28 (2): 428-31 4. Tunstall Pedoe DS. Sudden cardiac death in sport: spectre or preventable risk? Br J Sports Med 2000; 34 (2): 137-40 5. Tunstall Pedoe DS. Sudden death risk in older athletes: increasing the denominator. Br J Sports Med 2004; 38 (6): 671-2 6. Tunstall Pedoe DS. Morbidity and mortality in the London Marathon. In: Tunstall Pedoe DS, editor. Marathon medicine. London: RSM Press, 2000: 197-207 7. Tunstall Pedoe DS. Marathon myths and marathon medicine. In: Tunstall Pedoe DS, editor. Marathon medicine. London: RSM Press, 2000: 3-14

Correspondence: Dr Dan S. Tunstall Pedoe, 29 Meynell Crescent, London, E9 7AS, UK. E-mail: [email protected]

Sports Med 2007; 37 (4-5)