Beta-blocker therapy has been thought to be contraindicated in patients with systolic dysfunction heart failure. However, recent studies have shown that beta-blocker therapy in these patients may reduce mortality and decrease hospitalizations. Although this benefit has been shown in multiple studies, concerns still exist about the adverse effects beta-blocker therapy may have in patients with heart failure, including worsening of heart failure, hypotension, dizziness, bradycardia, and fatigue. These concerns may deter some physicians from prescribing beta blockers for these patients. The various studies on beta-blocker therapy in patients with heart failure have reported adverse effects from this class of medications, but none have established estimated risks for these adverse effects. Ko and associates performed an overview of randomized clinical trials of beta blockers in patients with heart failure to quantify adverse effects of this therapy.
The study was an overview of randomized trials of beta-blocker therapy in patients with heart failure. Trials included in the review had to meet the following inclusion criteria: random allocation of treatments, non-crossover design, placebo control, at least 100 participants in each treatment group, and a minimum of six months of follow-up. Of the 148 articles identified, nine met the inclusion criteria. A random-effects model was used to combine the results of the nine studies.
Beta-blocker therapy was found to increase the absolute annual risk of hypotension in 11 per 1,000 patients, dizziness in 57 per 1,000 patients, and bradycardia in 38 per 1,000 patients. The relative risk for these adverse effects was 1.41 for hypotension, 1.37 for dizziness, and 3.62 for bradycardia. All of these risks were significantly increased compared with placebo. There was no significant increase in the absolute risk for fatigue. Positive aspects of beta-blocker therapy included a reduction in all-cause mortality in 34 per 1,000 patients, a reduction in heart failure hospitalizations in 40 per 1,000 patients, and a reduction in worsening of heart failure in 52 per 1,000 patients. The overall withdrawal rate was 16 percent for beta-blocker therapy and 18 percent for placebo.
the authors conclude that although beta-blocker therapy is associated with some adverse effects, the increase in the absolute risk for these effects is small. They note that fewer patients withdrew from beta-blocker therapy than from placebo. This study should reduce concerns about prescribing beta-blocker therapy in patients with heart failure.
editor’s note: Despite beta-blocker therapy being shown to reduce morbidity and mortality in patients with heart failure, physicians still fear using this class of medication in these patients. In an accompanying editorial,1 Chatterjee argues that it is time to forget these fears. The true contraindications for beta-blocker therapy in patients with heart failure include severe bronchospasms, hypotension, severe bradycardia, and heart block. Even patients with chronic obstructive pulmonary disease and diabetes have been shown to benefit from beta-blocker therapy. Some of the concerns about these drugs can be eased by starting at lower dosages and titrating slowly. Using this strategy, physicians can use beta blockers safely in patients with heart failure.—k.e.m.