Perioperative Betablockers Reduce Cardiovascular Events In Patients Undergoing High Risk Non-Cardiac Surgery-A Meta-Analysis

Introduction: ACC/AHA 2006 guidelines recommend perioperative beta blockers(BB) for high risk cardiac patients (class IIa), intermediate and low cardiac risk patients (class IIb) undergoing non-cardiac surgery. Meta-analysis of trials on perioperative blockers up to April 2003 found insufficient evidence for reduction of major cardiovascular events. We analysed the current evidence on effects of perioperative beta-blockers in patients not on BB and undergoing non-cardiac surgery. Materials and Methods: We did a literature search for randomized placebo controlled clinical trials of perioperative beta blockers in patients undergoing high risk non-cardiac surgery. End points were 30 day total mortality, cardiovascular mortality, perioperative cardiovascular outcomes, non-fatal MI, unstable angina, ventricular tachycardia, congestive heart failure, non-fatal stroke,non-fatal cardiac arrest,hypotension, bradycardia, bronchospasm. Data was extracted on an intention-to-treat basis. Heterogeneity of the studies was analyzed by Cochran’s Q statistics. The Mantel-Haenszel fixed-effect model was used to calculate combined relative risks for outcomes. Results: 24 studies with 3454 patients were included. Perioperative BB showed statistically significant benefit in reducing perioperative cardiovascular events and non-fatal MI and a nominally statistically significant benefit for cardiovascular mortality. The other end points were not significantly different between the two treatment groups. The results are summarized in the table below. Conclusion: Perioperative beta blockers reduce cardiovascular events and their use is recommended in all patients without contraindications and undergoing non-cardiac surgery.