Sudden cardiac arrest in marathons

Sudden cardiac arrest in marathons

The popularity of endurance training and long-distance running races is rapidly growing. This is clearly evident in a recently published study which demonstrated that more than 29 million people in the US completed in marathons and half-marathons from 2010 to 2023.

The incidence of sudden cardiac arrest was relatively unchanged over 2 decades, according to the researchers. The incidence rate was 0.54 per 100,000 participants in 2000-2009 compared with 0.6 per 100,000 participants in 2010-2023. According to the researchers, the incidence rate of sudden cardiac death declined from 0.39 per 100,000 participants in 2000-2009 to 0.2 per 100,000 participants in 2010-2023. It is assumed that this reflects the effectiveness of properly designed emergency response plans that provide prompt resuscitation and defibrillation.

Sudden cardiac arrest during races was more common in men compared to women (1.12 per 100,000 vs. 0.19 per 100,000) and also more possible to occur in marathon races compared to half-marathons (1.04 per 100,000 vs. 0.47 per 100,000).

Coronary artery disease appears as the most common etiology (nearly 50%), while a significant proportion (40%) was labeled as unexplained. Interestingly, hypertrophic cardiomyopathy was the cause in only 7%.

The findings of the study show that:

1. The possibility of sudden cardiac arrest in marathons is relatively small, but non-negligible.
2. It is imperative in such races to have a structured emergency response plan.
3. A high clinical suspicion is required when managing master endurance athletes. Early identification of subclinical coronary artery disease and initiation of statins may significantly reduce the incidence of adverse events.

Reference:
Kim JH, et al. JAMA. 2025;doi:10.1001/jama.2025.3026.