The effectiveness of beta-blockers in women with congestive heart failure.

Abstract

BACKGROUND: Beta-blockers have been shown to improve survival in patients with congestive heart failure (CHF). However, few studies have looked at the effects of these medications specifically in women. OBJECTIVE: To determine the effectiveness of beta-blockers in women with CHF. PATIENTS: We conducted a retrospective cohort study that used administrative databases of all patients >65 years of age discharged with a diagnosis of CHF between January 1998 and March 2003 in Quebec, Canada. Follow-up information was available until March 31, 2004. METHOD: The cohort included 27,837 patients. Subjects with filled prescription for a beta-blocker (14,083 users) were compared with those who never filled such prescription (12,254 nonusers). The primary outcome was survival in women and men by beta-blocker use. RESULTS: There were 14,693 women (52% were prescribed beta-blockers) and 13,144 men (49% were prescribed beta-blockers). Women were older and had more hypertension, whereas men had more myocardial infarction. There was a significant survival benefit with beta-blockers use in both sexes (hazard ratio [HR] 0.79, 95% confidence interval [CI] 0.75-0.83 in women, and 0.76, 95% CI 0.72-0.80 in men). Sensitivity analyses adjusting for selection bias showed similar survival benefits in both sexes. Overall, men had a worse survival than women (HR 1.2, 95% CI 1.2-1.3 in men). CONCLUSIONS: Beta-blockers appear to improve survival from CHF as much in women as in men. Clinical trials involving large numbers of women are necessary to demonstrate potential treatment benefits.