Sex differences in the prognosis of congestive heart failure - Results from The Cardiac Insufficiency Bisoprolol Study (CIBIS II)

Background-Whether female sex is associated with a better prognosis in pati ents with congestive heart failure (CHF) remains uncertain. The Cardiac Ins ufficiency Bisoprolol Study (CIBIS) II showed that bisoprolol reduced all-c ause mortality and morbidity rates in CHF patients treated with diuretics a nd ACE inhibitors. We examined whether survival was different in men (n=213 2) and women (n=525) enrolled in CIBIS II. Methods and Results-Women differed from men with regard to age, NYHA functi onal classification, primary cause of CHF, and risk factors such as left bu ndle-branch block. After adjustment for baseline differences, the probabili ty of all-cause mortality was significantly reduced by 36% in women compare d with that in men (hazard ratio 0.64, 95% CI 0.47 to 0.86, P=0.003). Women also had a 39% reduction in cardiovascular deaths (hazard ratio 0.64, 95% CI 0.45 to 0.91, P=0.01) and a 70% reduction in deaths from pump failure (h azard ratio 0.30, 95% CI 0.13 to 0.70, P=0.005) compared with men. Kaplan-M eier survival analysis revealed a significant reduction in all-cause mortal ity among women treated with bisoprolol compared with men (6% versus 12% P= 0.01) but not among women treated with placebo (13% versus 18%, P=0.10). Ho wever, this sex/beta -blocker effect was not significant in multivariate an alysis. Conclusions-These results indicate that regardless of beta -blocker treatme nt and baseline clinical profile, female sex is a significant independent p redictor of survival in patients with CHF.