Abstract 17276: Implantable Cardioverter-Defibrillator Therapy in Women: Population-based Outomes
Background: Due to the low enrolment of women in implantable cardioverter-defibrillator (ICD) trials, there is controversy whether the survival benefit of ICDs applies to both sexes. Population-based data examining sex differences in ICD outcomes may provide further clarification.
Methods: Study data were derived from a provincial registry in British Columbia (BC), the Cardiac Services BC Registry, where all ICD recipients are recorded. Patients ≥18 years with a new ICD implant from Jan 2003 to Dec 2012 were included. Data were linked to BC Vital Statistics to determine all-cause mortality. Survival was assessed using Kaplan-Meier methods stratified by sex and compared using the log-rank test. The Cox proportional-hazards model was used to estimate the hazard ratios (HR) and 95% confidence intervals (CI) between sexes. The effect of demographics, comorbidities and medication use were explored and only factors with a p-value < 0.15 were included in the final model. Statistical analyses were performed with SAS software, version 9.3 (Cary, NC).
Results: There were 3905 new ICD implants; of these, 704 were women (18%). Women were younger and had a lower prevalence of comorbidities. Except for beta-blockers, women were less likely to be prescribed cardiac medications. The overall survival of women was greater than men; however, women had a higher re-operation rate for complications (Figure). After adjusting for age, diabetes, coronary artery disease, congestive cardiomyopathy, peripheral vascular disease, acquired heart surgery, and anti-arrhythmic drug use, the sex difference in mortality was attenuated, adjusted HR 0.91, (95% CI: 0.75,1.12).
Conclusions: Women may derive the same survival benefit as men but have a higher re-operation rate for complications. Ongoing analyses will determine whether the impact of sex on mortality differs among patients receiving an ICD for primary versus secondary prevention.
Author Disclosures: S. Cowan: Research Grant; Modest; Servier. Honoraria; Modest; Servier. Consultant/Advisory Board; Modest; Servier. M. Grubisic: None. L. Ding: None. N. Hawkins: None. A. Raymakers: None. P. Novak: Honoraria; Modest; Medtronic. M. Gao: None. J. Bashir: Other; Modest; Boston Scientific.
- © 2014 by American Heart Association, Inc.