Outcomes of Perioperative β-Blockade in Patients Undergoing Noncardiac Surgery: A Meta-Analysis

BACKGROUND: Several studies have evaluated the impact on myocardial infarction (MI), stroke, and overall mortality of perioperative beta-blocker use in patients undergoing noncardiac surgery (NCS). However, most studies did not have adequate sample size and statistical power and were therefore under-powered to adequately evaluate these endpoints. OBJECTIVE: To conduct a meta-analysis to determine the balance of benefits and harms associated with perioperative beta-blocker use in NCS. METHODS: A systematic literature search of MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials was conducted from January 1960 through February 2009. Manual reference search was performed to identify additional relevant trials. Randomized, double-blinded, placebo-controlled trials comparing the use of beta-blockers with placebo; using beta-blockers perioperatively in beta-blocker-naive patients undergoing NCS; and evaluating endpoints of MI, stroke, or all-cause mortality were included. RESULTS: Six trials (N = 10,183) met our inclusion criteria. Perioperative beta-blocker use was associated with a significant reduction in patients' odds of developing MI (OR 0.74, 95% CI 0.61 to 0.89) but a significant increase in odds of developing stroke (OR 1.98, 95% CI 1.23 to 3.20) and also a nonsignificant increase in mortality (OR 1.21, 95% CI 0.98 to 1.49) versus placebo. Control-rate meta-regression determined that patients with highest baseline odds of stroke had decreased relative odds of having a stroke with a beta-blocker versus placebo (beta coefficient -0.97;95% credible interval -1.04 to -0.90). CONCLUSIONS: When perioperative beta-blockers are used in NCS patients, there is a trade-off between reduction in MI and increase in stroke, with a troubling trend toward an increase in mortality. Patients with lower baseline odds of developing stroke appear to be at greater risk of beta-blocker-induced stroke.