Beta-blocker therapy for congestive heart failure: a systemic overview and critical appraisal of the published trials.

OBJECTIVE To evaluate the effect of beta-blockers on mortality and morbidity, and to provide an appraisal of the reliability of the available data. DATA SOURCES MEDLINE search for trials of beta-blockers for congestive heart failure (CHF). STUDY SELECTION All randomized trials of beta-blockers versus placebo, or greater than one month's duration, in patients with CHF. Eighteen published trials involving 2986 patients were selected. DATA EXTRACTION Independently by two authors. DATA SYNTHESIS The Yusuf-Peto method for combining data was used. Data were available on mortality in 2841 patients (95%), on hospitalization for heart failure in 1514 (51%) and on heart transplantation in 2330 (79%). There was a lower rate of death in the active treatment group (131 of 1606) [8.2] versus 155 of 1235 [12.6%]; OR = 72; 99% CI 0.51 to 1.00), a lower rate of hospitalization for heart failure (137 of 756 [18.1%] versus 218 of 758 [28.7%]; OR = 0.54; 99% CI 0.39 to 0.74) and a trend towards a lower proportion of patients receiving heart transplantation (15 of 1354 [l.1%] versus 26 of 976 [2.7%]; OR = 0.45; 99% CI 0.20 to 1.03). Ventricular function improved; however, there was no effect on exercise duration. Although the effects on mortality were nominally statistically significant, the use of formal methods of interim monitoring adapted for meta-analyses suggests that substantially more patients still need to be studied in large scales trials to provide reliable and conclusive evidence. CONCLUSIONS While the available data on the use of beta-blockers in CHF appear to be promising, they are neither complete nor robust. The routine use of beta-blockers in patients with heart failure should wait the results of ongoing studies.