Long distance running races are associated with a low risk of life-threatening events much often attributed to hypertrophic cardiomyopathy. However, retrospective analyses of aetiology lack consistency.Methods and results
Incidence and aetiology of life-threatening/fatal events were assessed in long distance races in the prospective Registre des Accidents Cardiaques lors des courses d'Endurance (RACE Paris Registry) from October 2006 to September 2012. Characteristics of life-threatening/fatal events were analysed by interviewing survivors and reviewing medical records including post-mortem data of each case. Seventeen life-threatening events were identified of 511 880 runners of which two were fatal. The vast majority were cardiovascular events (13/17) occurring in experienced male runners [mean (±SD) age 43 ± 10 years], with infrequent cardiovascular risk factors, atypical warning symptoms prior to the race or negative treadmill test when performed. Acute myocardial ischaemia was the predominant aetiology (8 of 13) and led to immediate myocardial revascularization. All cases with initial shockable rhythm survived. There was no difference in event rate according to marathons vs. half-marathons and events were clustered at the end of the race. A meta-analysis of all available studies including the RACE Paris registry (n = 6) demonstrated a low prevalence of life-threatening events (0.75/100 000) and that presentation with non-shockable rhythm [OR = 29.9; 95% CI (4.0–222.5), P = 0.001] or non-ischaemic aetiology [OR = 6.4; 95% CI (1.4–28.8), P = 0.015] were associated with case-fatality.Conclusion
Life-threatening/fatal events during long distance races are rare, most often unpredictable and mainly due to acute myocardial ischaemia. Presentation with non-shockable rhythm and non-ischaemic aetiology are the major determinant of case fatality.