Objective: Perioperative beta-blocker therapy has been proposed to improve outcome. Most of the trials conducted, however, lacked statistical power to evaluate the incidence of hard cardiac events and the relationship to the type of surgery. Therefore, we conducted a meta-analysis of all randomized controlled trials in which beta-blocker therapy was evaluated.
Methods: An electronic search of published reports on Medline was undertaken to identify studies published between January 1980 and November 2004 in English language journals. All studies reported on at least one of three endpoints: perioperative myocardial ischemia, perioperative nonfatal myocardial infarction, and cardiac mortality. Type of surgery, defined as low, intermediate, and high risk according to the American College of Cardiology/American Heart Association guidelines, was noted.
Results: In total, 15 studies were identified, which enrolled 1,077 patient. No significant differences were observed in baseline clinical characteristics between patients randomized to beta-blocker therapy and control/placebo. Beta-blocker therapy was associated with a 65% reduction in perioperative myocardial ischemia (11.0% vs. 25.6%; odds ratio 0.35, 95% confidence interval 0.23-0.54; P<0.001). Furthermore, a 56% reduction in myocardial infarction (0.5% vs. 3.9%, odds ratio 0.44, 95% confidence interval 0.20-0.97; P=0.04) and a 67% reduction (1.1% vs. 6.1%, odds ratio 0.33, 95% confidence interval 0.17-0.67; P=0.002) in the composite endpoint of cardiac death and nonfatal myocardial infarction were observed. No statistical evidence was observed for heterogeneity in the treatment effect in subgroups according to type of surgery (P for heterogeneity 0.2).
Conclusion: This meta-analysis shows that beta-blocker use in noncardiac surgical procedures is associated with a significant reduction of perioperative cardiac adverse events.