Benefits and risks associated with β-blocker prophylaxis in noncardiac surgery

Abstract

The benefits and risks associated with use of beta-blocker prophylaxis in noncardiac surgery (NCS) are described. Perioperative beta-blockade is recommended by the American College of Cardiology and the American Heart Association for use in patients already on beta-blockers or in high-risk patients undergoing NCS to reduce myocardial ischemia and myocardial infarction (MI); however, the recommendations are not as clear for patients undergoing intermediate- or low-risk NCS. Numerous trials have evaluated the effect of perioperative beta-blockers on MI, stroke, bradycardia, hypotension, overall mortality, and cardiovascular mortality in patients undergoing NCS. Several trials suggest that dosing, patient population, type of NCS, genetic polymorphisms, and type of anesthesia may be important in determining the benefits and risks of perioperative beta-blockade in these patients. In the meta-analyses evaluating beta-blockers in NCS, the balance of benefits to harms associated with aggressive perioperative beta-blocker therapy was not favorable. However, the largest, most recent trial drove the meta-analyses results and has some methodological caveats and limitations that must be considered. Recent meta-analyses have found that the use of beta-blockers reduces the rate of MI but increases the frequency of stroke, and these MIs and strokes can occur with differing severities. Perioperative use of beta-blockers in NCS can protect against postoperative MI but increases the risk of stroke, severe hypotension, and severe bradycardia. Although less common, the strokes are severe, and the troubling trend toward increasing cardiovascular and total mortality precludes the recommendation for their use in patients not previously treated with beta-blockers.