Chapter 77 - Sex differences in implantable cardioverter defibrillators: outcomes and utilization

Abstract

The incidence and prevalence of sustained ventricular arrhythmias and sudden cardiac death (SCD) are lower in women compared with men. Some of these differences can be explained, in part, to sex differences in the etiologies of heart disease—men are more likely to have coronary artery disease whereas women are more likely to have nonischemic cardiomyopathy or valvular heart disease. Women have been underrepresented in clinical trials examining the benefit of implantable cardioverter defibrillator (ICD) therapy for prevention of SCD in high-risk populations. While some data have suggested that women derive a lower survival benefit from ICD therapy, these studies were not powered to assess sex differences in overall survival. Women receiving ICDs for primary prevention of SCD are less likely to experience treated sustained ventricular arrhythmias compared with men. Women are also more likely to experience a significant complication related to ICD implantation compared with men. Sex disparities in referral for primary prevention ICD therapy have been reported despite current guideline recommendations, although this gap in referral appears to be narrowing. Whether sex differences in treatment decisions reflect treatment biases or patient preferences requires further study.