New Data on Perioperative β-Blockade for Noncardiac Surgery

For patients with multiple risk factors undergoing noncardiac, nonvascular surgery, perioperative β-blockers reduce mortality and cardiac morbidity, according to a study in the Journal of the American Medical Association. The protective effect is larger for patients with more risk factors, the authors found.

Using Veterans Health Administration (VA) databases, the researchers identified 37,805 propensity score–matched pairs of patients undergoing major noncardiac surgery who did and did not receive perioperative β-blockade, defined as an active outpatient prescription or receipt of β-blockers on the day of or the day after surgery. The 30-day mortality and cardiac morbidity (cardiac arrest or Q-wave myocardial infarction) were compared between groups.

In this VA population, the rates of perioperative β-blocker exposure were 40.3 percent overall, 66.7 percent for patients undergoing vascular surgery, and 37.4 percent for those undergoing nonvascular surgery. The likelihood of perioperative β-blockade increased from 25.3 percent for patients with no revised cardiac risk index factors to 71.3 percent for those with four or more risk factors. The overall 30-day mortality was 1.1 percent, and cardiac morbidity was 0.9 percent.

On propensity-matched analysis, perioperative β-blockers were associated with lower mortality among higher-risk patients. The relative risk (RR) was 0.63 for patients with two revised cardiac risk index factors, with a number needed to treat (NNT) of 105. For patients with the risk factors, the RR was 0.54 and the NNT 41; for those with four or more risk factors, RR was 0.40 and the NNT 18.

Perioperative β-blockade reduced mortality risk only for patients undergoing nonvascular surgery. The nonvascular surgery group also had a significant reduction in cardiac morbidity: RR 0.67, NNT 339.

There is continued controversy over the use of perioperative β-blockers for patients undergoing major noncardiac surgery. Current class I recommendations call only for continuation of pre-existing β-blocker therapy [London MJ, et al. Association of perioperative β-blockade with mortality and cardiovascular morbidity following major noncardiac surgery. JAMA 2013; 309:1704–1713].