Allan S. Brett, MD Reviewing Richman JS et al., JAMA Surg 2014 Oct 149:1031
Another observational study suggests that patients who already take β-blockers should continue to receive them perioperatively.
Based on several observational studies, a 2014 guideline from the American College of Cardiology and the American Heart Association (ACC/AHA) recommends that patients who take β-blockers chronically and who undergo noncardiac surgery should continue to receive β-blockers perioperatively. In the latest study of this issue, researchers identified 14,420 patients at U.S. Veterans Affairs hospitals who were receiving outpatient β-blocker therapy, underwent noncardiac surgery, and spent at least 2 days in the hospital postoperatively. Eighty percent of patients received β-blockers both within the immediate perioperative period (i.e., 24 hours before incision through discharge from the postanesthesia care unit) and on at least 1 of the first 2 postoperative days; 20% did not receive β-blockers in this manner.
Overall, 3.3% of patients experienced major adverse cardiovascular or cerebrovascular events (MACCE) within 30 days. In adjusted analyses with propensity-score matching, patients who continued to receive perioperative β-blockade (according to the above-noted criteria) were significantly less likely to experience MACCE than were patients who did not (odds ratio, 0.75). Thirty-day mortality (2.1% overall) also was significantly lower in the β-blocker–continuation group (OR, 0.74). The apparent benefit of β-blocker continuation was limited to high-risk patients — those with scores ≥3 on the Revised Cardiac Risk Index (NEJM JW Gen Med Sep 17 1999).
Most of the observational studies (including the current one) about this question are necessarily messy: Unmeasured confounding variables are likely, how long these patients took β-blockers prior to surgery is unclear, and we don’t know whether β-blockers were given continuously after the 1 or 2 perioperative days. Nevertheless, the results support current recommendations to continue β-blockers perioperatively.