Which patients undergoing noncardiac surgery benefit from perioperative beta-blockers?

Long-acting beta-blockers=fewer MIs

A population-based, retrospective cohort analysis with 37,151 patients over 65 years of age compared perioperative beta-blocker therapy using atenolol (a long-acting beta-blocker) with metoprolol (a shorter-acting beta-blocker) for elective surgery.⁵ Investigators excluded patients with symptomatic coronary disease.

Patients taking atenolol had fewer MIs (1.6% vs 2.0%, P=.004) and fewer deaths (1.2% vs 1.6%, P=.007) when compared with metoprolol. Atenolol produced a 13% relative risk reduction over metoprolol for MI or death after adjusting for age, sex, type of surgery, and use of furosemide, calcium-channel blockers, angiotensin-converting enzyme inhibitors, and statins (comparative NNT=165).

Dose titration by heart rate

An observational cohort study with 272 patients undergoing elective major vascular surgery (mean age 67.4 years, 80% male) evaluated whether higher doses of beta-blockers and tight heart rate control reduced perioperative myocardial ischemia and troponin T release.⁶ Patients with higher beta-blocker doses, lower heart rates, and lower absolute change in heart rate during the perioperative period had significantly less perioperative myocardial ischemia and troponin T release (P<.0001).

The DECREASE-II trial, a prospective cohort study with 1476 patients undergoing elective open abdominal aortic or infrainguinal arterial reconstruction also found that patients with heart rates <65 beats per minute had a significantly lower risk of cardiac death or MI at 30 days postoperatively (1.3% vs 5.2%, OR=0.24; 95% CI, 0.09–0.66).⁷

Begin therapy 30 days before surgery

Authors of a systematic review including 5 RCTs (586 total patients) evaluating perioperative beta-blocker therapy in noncardiac surgery concluded that beta-blocker therapy should begin as long as 30 days prior to surgery to allow for titration of dose to the target heart rate and continue at least throughout hospitalization (longer if adequate medical follow-up can be arranged postoperatively).⁸

Recommendations from others

The American College of Cardiology/American Heart Association Task Force on Practice Guidelines⁹ recommends:

• continuing beta-blockers for patients already receiving them to treat angina, symptomatic arrhythmias, and hypertension before their surgical risk evaluation.
• initiating perioperative beta-blocker therapy for patients undergoing vascular surgery if they are at high cardiac risk, as evidenced by ischemia on preoperative testing.
• considering perioperative beta-blocker therapy for patients undergoing intermediate-to high-risk procedures if preoperative risk assessment identifies them as having intermediate or higher cardiac risk, and for patients undergoing vascular surgery who are at low cardiac risk.