Sudden cardiac arrest during marathons among young, middle-aged, and senior runners

There is limited evidence showing a relationship with age in the incidence of sudden cardiac arrest during exercise, which can be lethal at times.

To examine the incidence by age group in sudden cardiac arrest, we prospectively observed cases of sudden cardiac arrest in full marathons certified by the Japan Association of Athletics Federations held between April 2011 and March 2019. Sudden cardiac arrest was defined as collapse during or 1 h after the race requiring chest compressions or the use of an automatic electrical defibrillation.

4.1 million persons ran in 516 marathons. Of the participants, 78.6 % were men. By age group, 37.4 %, 34.7 %, 19.6 %, and 8.3 % belonged to the < 40 s, 40 s, 50 s, and ≥ 60 s groups, respectively. During the study period, 69 sudden cardiac arrests (1.7 per 100,000 participants, 95 % confidence interval [CI]: 1.3-2.1) were observed, of which 66 were men. The incidence per 100,000 runners of sudden cardiac arrest was 0.9 (95 % CI: 0.4, 1.4), 0.9 (95 % CI: 0.4, 1.4), 2.6 (95 % CI: 1.5, 3.8), and 5.5 (95 % CI: 2.9, 8.2) for those in their under 40 s, 40 s, 50 s, and over 60 s, respectively, with higher rates for older age groups. Compared to men, the cases of SCA among women were less common (only three cases), and the incidence did not differ by age group.

Men, unlike women, had a higher incidence of sudden cardiac arrest during marathons according to age. Identification of this high-risk population could be important information in encouraging marathoners pre-participation self-screening.