Comparison of Long-Term Survival Following Sudden Cardiac Arrest in Men Versus Women

Abstract

Sudden cardiac death (SCA) is a major cause of mortality with estimates of 450,000 deaths annually in the United States. The incidence of SCA differs between the sexes. Data regarding survival of women compared with men after SCA are, however, conflicting. We, therefore, examined the long-term survival of women versus men after SCA. A total of 1,433 (41% women; 44% out-of-hospital) survivors of SCA at our institution between 2002 and 2012 were followed to the primary end point of death through February 20, 2017. Women in our cohort were older (p = 0.02), were less likely to be white (p = 0.01), or to have suffered an acute myocardial infarction at the time of SCA (p < 0.001). They also had significantly shorter PR (p < 0.001) and QRS (p < 0.001) durations on their surface electrocardiogram, were more likely to present with an initial ventricular rhythm other than ventricular tachycardia or ventricular fibrillation (29% vs 22%, p = 0.001) and less likely to receive an implantable cardioverter defibrillator (22% vs 31%, p < 0.001). Over a median follow-up of 3.6 years, 674 (45%) patients died (53% women vs 43% men, p < 0.001). After adjusting for unbalanced baseline covariates, the sex difference in survival disappeared (hazard ratio 1.05; 95% confidence interval 0.85 to 1.29, p = 0.66). In conclusion, our results demonstrate comparable long-term mortality after SCA for men and women. Differences in unadjusted mortality are mainly due to older age, different risk profiles at the time of index event, and differential treatment with implantable cardioverter defibrillator.