The New England Journal of Medicine recently published a study examining cases of sudden cardiac arrest in both competitive and non-competitive sports that occurred in Canada from 2008-2014 in order to determine whether pre-participation screening may have helped in identifying at-risk athletes.

The study used a registry of all out-of-hospital cardiac arrests that occurred to persons aged 12 to 45 years-old in a region of the province of Ontario. After analyzing data related to each incident such as ambulance call reports, autopsy reports, in-hospital records and interviews of patients and family, the researchers determined that 74 cardiac events occurred within one hour of participation in sports-related activities during 18.5 million person-years of observation. Out of these 74 events, 16 occurred during competitive sports and 58 occurred during non-competitive sports. Out of these 74 incidents, only 3 were determined to have been potentially preventable if the athletes had undergone screening for cardiac defects.

The study determined that the prevalence of sudden cardiac arrests was approximately 0.76 cases per 100,000 athlete-years, with 43.8% of the athletes surviving at least until they could be discharged from the hospital.

The researchers determined that the primary cause for sudden cardiac arrest varied with age. Athletes younger than 35 years old were likely to experience cardiac arrest resulting from structural and arrhythmia-related cardiac disease. Athletes between the ages of 35-45 were more likely to suffer from complications from coronary artery disease. Hypertrophic obstructive cardiomyopathy (HOCM) was an uncommon cause of cardiac arrest in the data – accounting for only 3 cases among the 16 competitive athletes that experienced sudden cardiac arrest – despite many studies that point to HOCM as being the primary cause of cardiac arrest in young athletes.

The researchers concluded that more than 80% of the cases would not have been prevented had the athletes been screened via systematic clinical pre-participation or electrocardiogram-based screening thus casting doubts on the health benefits of pre-participation screening for young athletes.

Reference:

Landry, CH, Allan, KS, Connelly, KA et al. Sudden Cardiac Arrest during Participation in Competitive Sports. N Engl J Med 2017; 377:1943-1953.