Long-Term Survival After Implantable Cardiac Defibrillator Therapy According to Sex: A Propensity Matched Study

Background: Whether the sex factor influences the benefit of the implantable cardioverter-defibrillator (ICD) for the prevention of sudden death remains a subject of debate. Using a prospective registry, we sought to analyze the survival and time to first ICD therapy according to sex. Materials and Methods: Retrospective analysis of a prospective cohort of patients undergoing an ICD implant from 2008 to 2019. Data about time to first appropriate therapy, type of therapy administered, and incidence and causes of mortality were collected. Results: Among 756 ICD patients, 150 (19.8%) were women. Women were younger (51 ± 15 years vs. 61 ± 14 years; p < 0.001) and showed a lower rate of ischemic cardiomyopathy (23% vs. 54%; p < 0.001) and atrial fibrillation (12% vs. 19%; p = 0.05). Women had higher left ventricular ejection fraction (39% ± 17% vs. 35% ± 13%) and showed more frequently left bundle branch block (39% vs. 28%, p = 0.027). The rate of primary prevention (68% vs. 59.6%; p = 0.058) and cardiac resynchronization therapy (27% vs. 19%, p = 0.02) were higher in women. After a median follow-up of 46 months (3382 patient-years), the incidence of both the primary combined endpoint of mortality/transplant (20% vs. 29%; logrank = 0.031) and ICD therapies (27% vs. 34%; p = 0.138) were lower in women. According to the propensity score-matching analysis, no differences were observed between both sexes with respect to the incidence of mortality/transplant (24.8% vs. 28.6%; logrank = 0.88), ICD therapies (28% vs. 27%; logrank = 0.17), and main cause of death (heart failure [HF]). Conclusions: The clinical characteristics at the moment of ICD implant are different between sexes. After adjusting them, both sexes equally benefit from the ICD. HF is the main cause of mortality both in men and women.