Clinical Effectiveness of CRT and ICD Therapy in Men and Women with Heart Failure: Findings from IMPROVE HF

Background —Many clinical trials have demonstrated a benefit for cardiac resynchronization (CRT) and implantable cardioverter-defibrillator (ICD) therapies in patients with heart failure (HF) and reduced ejection fraction (EF), yet questions have been raised with regard to the benefit of ICDs for women. The purpose of this study was to determine the clinical effectiveness of CRT and ICD therapy as a function of sex in outpatients with HF and reduced EF (≤35%). Methods and Results —Data from IMPROVE HF were analyzed by device status and sex among guideline-eligible patients for vital status (alive/dead) at 24 months. Multivariate Generalized Estimating Equations analyses were conducted adjusting for baseline patient and practice characteristics. In the ICD/CRT-D eligible cohort (n=7748), there were 5,485 (71%) men and 2,261 (29%) women. In the CRT-P/CRT-D eligible cohort (n=1188) there were 824 (69%) men and 364 (31%) women. The clinical benefit associated with ICD/CRT-D therapy was similar in both men and women (men adjusted OR 0.71, 95% CI 0.57-0.87, p=0.0012; women adjusted OR 0.65, 95% CI 0.49-0.85, p=0.0019). For CRT-P/CRT-D, the associated benefits showed no significant heterogeneity (men adjusted OR 0.59, 95% CI 0.331.06, p=0.0793; women adjusted OR 0.44, 95% CI 0.22-0.90, p=0.0243). The device*sex interactions were not significant (p=0.4441 for CRT-P/CRT-D and p=0.5966 for ICD/CRT-D). Conclusions —The use of guideline-directed CRT and ICD therapy was associated with substantially reduced 24 month mortality in eligible men and women with HF and reduced EF. Device therapies should be offered to all eligible HF patients, without modification based on sex.