Epidemiology of sudden cardiac death and sudden cardiac arrest with resultant disability during high school organized sport in Japan

Objectives: To examine the incidence and survival rates of sudden cardiac arrest that were documented during school organized sports in Japan. Design: Retrospective cohort study. Methods: Insurance claim data of cardiac events (sudden cardiac death and sudden cardiac arrest with resultant disabilities) that occurred during Japanese high school organized sports between 2009 and 2018 were retrieved. Participation data from All Japan High School Athletic Federation and Japan High School Baseball Federation were used for incidence rate calculations. Incidence rate ratios with 95 % confidence interval were calculated to compare the risk by sports and sex. The survival rate was calculated with the proportion of resuscitated cases to total number of cardiac events in this dataset. Results: A total of 55 cardiac events (25 survivors and 30 deceased) were identified in the dataset. The majority affected male student-athletes (92.7 %). The frequency and incidence rate of cardiac events were highest in male baseball (n = 16 [29.1 %], incidence rate: 0.91 per 100,000 athlete-years). Incidence rate ratio revealed that male basketball (2.19, 95 % confidence interval: 1.04–4.60), male baseball (2.31, 95 % confidence interval: 1.32–4.03), and first-year male baseball (4.11, 95 % confidence interval: 2.10–8.07) had significantly higher risk of cardiac events, compared to the overall incidence rate (0.38 per 100,000 athlete-years). The survival rates were 37.5 % in the first half (2009–2013) and 56.5 % in the latter half (2014–2018) of the study period. Conclusions: The risk of cardiac events was highest in male, baseball, first-year student-athletes. Rapid AED application by bystanders should be advocated to enhance better survival.