Sports‐Related Out‐of‐Hospital Cardiac Arrest due to External Causes, Including Commotio Cordis, at Schools in Japan

Introduction To describe the characteristics and outcomes of sports‐related out‐of‐hospital cardiac arrest (OHCA) due to external causes, including commotio cordis, during school‐supervised sports activities in Japan's elementary schools, junior high schools, high schools, and technical colleges. Methods OHCA data (2008–2022) were obtained from the Stop and Prevent cardIac aRrest, Injury, and Trauma in Schools (SPIRITS)—a nationwide database of OHCAs occurring under school supervision across Japan. We identified sports‐related OHCAs with external causes and summarized patients' characteristics, bystander interventions, available response intervals, and survival outcomes. Results We identified 30 sports‐related OHCA cases due to external causes. The most frequently played sports were soccer/futsal ( n = 8), baseball ( n = 8), and swimming ( n = 4). The leading etiology was commotio cordis ( n = 15), followed by drowning ( n = 8). Among the 15 cases meeting our operational definition of commotio cordis, automated external defibrillator (AED) pads were applied in 14 (93%), shocks were delivered in 13 (87%), and 12 (80%) achieved a favorable neurological outcome. Among other external causes ( n = 15), ventricular fibrillation occurred in 4/15 (27%), AED pads were applied in 7/15 (47%), shocks were rare (1/15, 7%), and 1/15 (7%) achieved favorable neurological outcomes. Conclusions Nationwide case‐level reconstruction revealed distinct mechanism‐to‐response pathways. Although these descriptive data cannot establish the causal effects of the public access defibrillation programs or other interventions on outcomes, they highlight potentially actionable, mechanism‐specific opportunities for emergency response and prevention.