Perioperative beta-blockers for preventing surgery-related mortality and morbidity: A systematic review and meta-analysis

BACKGROUND: Perioperative beta-blockers are suggested to reduce cardiovascular mortality, myocardial-ischemia/infarction, and supraventricular arrhythmias after surgery. We reviewed the evidence regarding the effectiveness of perioperative beta-blockers for improving patient outcomes after cardiac and noncardiac surgery. METHODS: Eleven large databases were searched from the time of their inception, until October 2005. Various online-resources were consulted for the identification of unpublished trials and conference abstracts. We included randomized, controlled trials comparing perioperative beta-blockers with either placebo or the standard-of-care. Of the 3680 retrieved titles, 69 met inclusion criteria for analysis. Odds ratios (OR) assuming random effects were computed in the absence of significant clinical heterogeneity. RESULTS: beta-Blockers reduced the frequency of ventricular tachyarrhythmias [OR (cardiac surgery): 0.28, 95% CI 0.13-0.57; OR (noncardiac surgery): 0.56, 95% Cl 0.21-1.45], atrial fibrillation/flutter [OR (cardiac surgery): 0.37, 95% CI0.28-0.48], other supraventricular arrhythmias [OR (cardiac surgery): 0.25, 95% CI 0.18-0.35; OR (noncardiac surgery): 0.43, 95% Cl 0.14-1.37], and myocardial ischemia [OR (cardiac surgery): 0.49, 95% Cl 0.17-1.4; OR (noncardiac surgery): 0.38, 95% Cl 0.21-0.691. Length of hospitalization was not reduced [weighted mean difference (cardiac surgery): -0.35 days, 95% Cl -0.77-0.07; weighted mean difference (noncardiac surgery): -5.59 days, 95% Cl -12.22-1.04] and, in contrast to previous reports, beta-blockers did not reduce mortality [OR (cardiac surgery): 0.55, 95% CI 0.17-1.83; OR (noncardiac surgery): 0.78, 95% Cl 0.33-1.87], and they had no influence on the occurrence of perioperative myocardial infarction [OR (cardiac surgery): 0.89, 95% Cl 0.53-1.5; OR (noncardiac surgery): 0.59; 0.25-1.39]. CONCLUSIONS: beta-Blockers reduced perioperative arrhythmias and myocardial ischemia, but they had no effect on myocardial infarction, mortality, or length of hospitalization.