Perioperative issues: myocardial ischemia and protection--beta-blockade.

Approximately one third of patients undergoing noncardiac surgery have coronary artery disease, and cardiovascular complications are an important cause of perioperative morbidity and mortality. Several algorithms are available to assess the risk for peri-operative cardiac events. Although preoperative risk assessment is useful in identifying patients at greatest risk for cardiac complications, recent investigations have provided additional guidance in choosing interventions to improve perioperative outcomes. These investigations show that perioperative beta-blockers significantly reduce morbidity and mortality in noncardiac surgery and appear to offer the greatest benefit to high-risk patients. Because of the lower complication rate in intermediate- and low-risk patients and the absence of large randomized controlled trials, the role of beta-blockers in this population is less well-defined.