Global incidence of sudden cardiac arrest in young athletes and military members: a systematic review and meta-analysis

Objectives The goals of this review are to evaluate the quality of the evidence on the incidence of sudden cardiac arrest and death (SCA/D) in athletes and military members; and to estimate annual incidence of SCA/D. Data Sources MEDLINE, Embase, Cochrane CENTRAL, Web of Science, BIOSIS, Scopus, SPORT discus, PEDro, and clinicaltrials.gov were searched from inception to dates between 2/21/19 and 7/29/19. Study Selection Studies which reported incidence of SCA/D or both in athletes, or military members under age 40 were eligible for inclusion. 40 studies were identified for inclusion Data Extraction Risk of bias was assessed using a validated, customized tool for prevalence studies in all included studies. 12 were found to be low ROB, with the remaining 28 moderate or high ROB. Data was extracted for narrative review, and meta-analysis. Data Synthesis Random-effects meta-analysis was performed in studies judged to be low risk of bias in two separate categories: 5 studies on regional or national level data including athletes at all levels, and both sexes included 130 events of SCD, with a total of 11,272,560 athlete years showing a cumulative incidence rate of 0.98 [95%CI: 0.62, 1.53] per 100,000 athlete years, with high heterogeneity with I2 of 78%; 3 Studies focusing on competitive athletes between the ages of 14 and 25 were combined, and included 183 events, and 17,798758 athlete years showing an incidence rate of 1.91[95%CI: 0.71; 5.14] per 100,000 athlete years with high heterogeneity with I2 of 97%. Conclusion The worldwide incidence of SCD is a rare event. Low risk of bias studies indicate levels of SCD to be below 2 per 100,000 athlete years. Overall, the quality of the evidence available on the subject of SCA/D is low, but there are high quality individual studies to inform the question of incidence levels. PROSPERO Registration CRD42019125560 Key Points There are several published articles which give a clear picture on the estimate of sudden cardiac arrest and death in athletes and military members, but the overall state of the literature has substantial risk of bias, with only 12 of 40 included articles at low risk of bias. Meta-analysis of sudden cardiac death was shown to be rare overall in athletes, with high quality, large population level studies synthesized to show a rate of 0.98 [95%CI: 0.62, 1.53] per 100,000 athlete years, and more focused studies on competitive younger athletes synthesized to show a rate 1.91[95%CI: 0.71; 5.14] per 100,000 athlete years. There was high heterogeneity present in both meta-analyses.