Cardiac arrests are rare during competitive long-distance runs

Nearly 11 million people ran marathons or half-marathons in the USA between 2000 and 2009. Fifty-nine had a cardiac arrest during or just after the race, and 42 of them died, according to a new study. Cardiac arrests were more common in men (0.90/100 000; 95% CI 0.67 - 1.18) than women (0.16, 0.07 - 0.31), and more arrests occurred during or after marathons (1.01/100 000; 0.72 - 1.38) than half-marathons (0.27, 0.17 - 0.43).

The authors found their 59 cases through a comprehensive search of online resources, including race websites, local newspapers, and public search engines. They wrote to survivors and next of kin for more details and analysed medical records. Runners who arrested had a mean age of 42 years, but those who died were younger than those who survived. Of the 23 people with complete medical details who died, 15 had hypertrophic cardiomyopathy. Most of the handful of survivors with complete medical records had ischaemic heart disease.

With one cardiac arrest per 184 000 runners and one sudden death per 259 000 runners, long-distance races look less risky than collegiate athletics (one death per 43 770 participants per year), triathlons (one death per 52 630 participants), and jogging (one death per 7 620 previously healthy middle-aged joggers), say the authors. Male marathon runners have the highest risk, and it seems to be increasing, although firm conclusions are difficult from such limited numbers.

Kim JH et al. N Engl J Med 2012;366:130-140.