Beta-blockers and outcome in heart failure and atrial fibrillation: a meta-analysis.

OBJECTIVES The purpose of this study was to analyze the effect of beta blockade on outcome in patients with heart failure (HF) and atrial fibrillation (AF). BACKGROUND Beta-blockers are widely used in patients with HF and AF. Recommendation in current HF guidelines, however, is based on populations in which the most patients had sinus rhythm. Whether beta-blockers are as useful in AF is uncertain. METHODS Studies were included that investigated the effect of placebo-controlled, randomized beta-blocker therapy in patients with AF at baseline and HF with reduced systolic left ventricular ejection fraction (LVEF) <40%. RESULTS We identified 4 studies, which enrolled 8,680 patients with HF, and 1,677 of them had AF (19%; mean 68 years of age; 30% women); there were 842 patients treated with beta-blocker, and 835 with placebo. In AF patients, beta-blockade did not reduce mortality (odds ratio [OR]: 0.86 [95% confidence interval (CI): 0.66 to 1.13]; p = 0.28), while in sinus rhythm patients, there was a significant reduction (OR: 0.63 [95% CI: 0.54 to 0.73]; p < 0.0001). Interaction analysis showed significant interaction of the effects of beta-blocker therapy in AF versus that in sinus rhythm (p = 0.048). By meta-regression analysis, we did not find confounding by all relevant covariates. Beta-blocker therapy was not associated with a reduction in HF hospitalizations in AF (OR: 1.11 [95% CI: 0.85 to 1.47]; p = 0.44), in contrast to sinus rhythm (OR: 0.58 [95% CI: 0.49 to 0.68]; p < 0.0001). There was a significant interaction of the effects of beta-blocker therapy in AF versus that in sinus rhythm (p < 0.001). CONCLUSIONS Our findings suggest that the effect of beta-blockers on outcome in HF patients with reduced systolic LVEF who have AF is less than in those who have sinus rhythm.