Impact of Sudden Cardiac Arrest in Competitive Sports: Insights from a Canadian Study
Concerns Over Sudden Cardiac Arrest
A recent study from Canada, published in the New England Journal of Medicine, explores the frequency and implications of sudden cardiac arrest during competitive sports. Many individuals, regardless of existing heart conditions, often express anxiety about the possibility of experiencing a sudden cardiac arrest—defined as a sudden loss of heart function—while engaging in sports. Given the potential for fatal outcomes, these concerns are valid.
Methodology: Analyzing EMS Cardiac Arrest Data
To investigate the risk associated with sports participation, researchers in Ontario analyzed nearly six years of data (2009-2014) from the Rescu Epistry database. This provincial registry encompasses all instances of cardiac arrest occurring outside hospital settings, where emergency medical services (EMS) intervened. The study meticulously estimated the number of competitive and recreational athletes in Ontario using data from sporting organizations and census information.
Incidence Rate of Sudden Cardiac Arrest
The researchers focused on individuals aged 12 to 45 who experienced sudden cardiac arrest during or within one hour after engaging in a sporting activity. The incidence of sudden cardiac arrest was quantified using athlete-years, whereby each athlete’s data counted once for each year of participation. The study accounted for 2.1 million athlete-years, leading to several important findings:
– The incidence of sudden cardiac arrest was recorded at 0.76 cases per 100,000 athlete-years within this demographic.
– Among competitive athletes, race events and soccer were linked to the highest rates of sudden cardiac arrest. In contrast, gym workouts and running were the most common activities for non-competitive athletes.
– For both competitive and non-competitive athletes under 35, arrhythmia (abnormal heart rhythm) was the leading cause of sudden cardiac arrest. For athletes aged 35 to 45, coronary artery disease emerged as the primary cause.
Limitations of the Study
The authors acknowledged several limitations in their research, including:
– The retrospective nature of the analysis meant that the exact cause of death for some individuals in the Rescu Epistry database could not be conclusively determined.
– It is possible that some athletes at risk for sudden cardiac arrest opted out of participating in sports, potentially inflating the incidence reported in the study.
– Competitive athletes may have experienced sudden cardiac arrests during recreational sports, which could skew the incidence rates for competitive activities.
– Some incidents could have occurred while athletes were resting or more than one hour post-activity, which might result in underreporting the risks associated with sports.
Structural Heart Disease as a Rare Factor
One clear takeaway from the study is that structural heart disease, often a congenital defect not affecting the heart’s blood vessels, is an uncommon cause of sudden cardiac arrest linked to competitive sports. In fact, sudden cardiac deaths during competitive sports are rare, and most cases would not have been detected through standard pre-participation screenings. Therefore, individuals with such conditions can generally feel assured about their capacity to engage in sports, provided they consult with their healthcare provider beforehand.
Written by Raymond Quan, MASc, MBA
Reference: Landry, C.H., Allan, K.S., Connelly, K.A., Cunningham, K., Morrison, L.J., M.D., and Dorian, P., Sudden Cardiac Arrest during Participation in Competitive Sports, The New England Journal of Medicine, 377;20 (November 16, 2017).