Cardiovascular etiologies and risk factors of survival outcomes after resuscitation for out-of-hospital cardiac arrest: data from the KoCARC registry

Abstract Background The outcomes and characteristics of out-of-hospital cardiac arrest (OHCA) vary across geographic regions. The etiologies and prognoses of OHCA in Asian populations remain less established. This study aimed to investigate the etiologies and clinical characteristics of patients successfully resuscitated after OHCA and identify predictors of survival outcomes. Methods Data were extracted from a South Korean multicenter prospective registry of OHCA that included 64 tertiary hospitals from 2015 to 2018 (n=7577). The primary outcome was in-hospital mortality, and secondary outcome was the grade-1 cerebral performance category (CPC) score at discharge. Results Of the 7577 patients, 2066 achieved return of spontaneous circulation (ROSC) and were hospitalized and 915 (44·2%) presented with ventricular arrhythmia (VA) as their initial rhythm or on admission. The leading cause was obstructive coronary artery disease (n=413; 20·0%). Sudden unexplained death syndrome (SUDS) accounted for 67·5% of survivors, which were significantly lower with VA (82·7% vs. 48·3%, p<0.001). VA was an independent predictor of in-hospital mortality (adjusted hazard ratio [aHR] 0·72, 95% confidence interval 0·60–0·87) and the grade-1 CPC score at discharge (aHR 3·63, 95% CI 2·56–5·15). Other predictors of the primary outcome included age, ROSC on arrival, total arrest time, alertness on admission, extracorporeal membrane oxygenation use, targeted temperature management, implantable cardioverter defibrillator use, and coronary vasospasm. Conclusions SUDS was common in patients with ROSC after OHCA and thus needs to be evaluated comprehensively. VA was independently associated with favorable survival outcomes at discharge. Further management may improve clinical outcomes in patients with OHCA, particularly those with VA.