Objectives: We sought to evaluate the current evidence for an effect of beta-blockade treatment on mortality in patients with congestive heart failure (CHF).
Background: Although numerous small studies have suggested a benefit with beta-blocker therapy in patients with heart failure, a clear survival benefit has not been demonstrated. A recent combined analysis of several studies with the alpha- and beta-adrenergic blocking agent carvedilol demonstrated a significant survival advantage; however, the total number of events was small. Furthermore, it is unclear if previous studies with other beta-blockers are consistent with this finding.
Methods: Randomized clinical trials of beta-blockade treatment in patients with CHF from January 1975 through February 1997 were identified using a MEDLINE search and a review of reports from scientific meetings. Studies were included if mortality was reported during 3 or more months of follow-up.
Results: We identified 35 reports, 17 of which met the inclusion criteria. These studies included 3,039 patients with follow-up ranging from 3 months to 2 years. Beta-blockade was associated with a trend toward mortality reduction in 13 studies. When all 17 reports were combined, beta-blockade significantly reduced all-cause mortality (random effect odds ratio [OR] 0.69, 95% confidence interval [CI] 0.54 to 0.88). A trend toward greater treatment effect was noted for nonsudden cardiac death (OR 0.58, 95% CI 0.40 to 0.83) compared with sudden cardiac death (OR 0.84, 95% CI 0.59 to 1.2). Similar reductions in mortality were observed for patients with ischemic (OR 0.69, 95% CI 0.49 to 0.98) and nonischemic cardiomyopathy (OR 0.69, 95% CI 0.47 to 0.99). The survival benefit was greater for trials of the drug carvedilol (OR 0.54, 95% CI 0.36 to 0.81) than for noncarvedilol drugs (OR 0.82, 95% CI 0.60 to 1.12); however, the difference did not reach statistical significance (p = 0.10).
Conclusions: Pooled evidence suggests that beta-blockade reduces all-cause mortality in patients with CHF. Additional trials are required to determine whether carvedilol differs in its effect from other agents.