Sex differences in implantable cardioverter-defibrillator implantation indications and outcomes: lessons from the Nationwide Israeli-ICD Registry

AIMS: Implantable cardioverter-defibrillators (ICDs) improve survival in certain high arrhythmic risk populations. However, there are sex differences regarding both the utilization and the benefit of these devices. Using a prospective national ICD registry, we aim to compare the indications for ICD implantation as well as outcomes in implanted women vs. men. METHODS AND RESULTS: All subjects implanted with an ICD or cardiac resynchronization therapy with a defibrillator (CRTD) in Israel between July 2010 and February 2013 were included. A total of 3544 subjects constructed the baseline cohort, of whom 615 (17%) were women. Women had the same age (64 years) and rate of secondary prevention indication (26%) as men. However, women were more likely than men to have significant heart failure symptoms (52 vs. 45%), QRS > 120 ms (41 vs. 36%), and a higher rate of non-ischaemic cardiomyopathy (54 vs. 21%, all P values <0.05). Using multivariate analysis, women were more likely to undergo CRTD implantation (odds ratio = 1.8, P < 0.01). Follow-up data were available for 1518 subjects with a mean follow-up of 12 months. During follow-up, there were no significant differences among genders in the rate of any single or the combined outcomes of appropriate device therapies, heart failure admissions, or death. First-year re-intervention rate was double among women (5.6 vs. 3.0%, P < 0.01). CONCLUSION: In real-world setting, women implanted with an ICD differ significantly from men in their baseline characteristics and in the use of CRTD devices. These, however, did not translate into outcome differences.