The effects of perioperative β-blockade: Results of the Metoprolol after Vascular Surgery (MaVS) study, a randomized controlled trial

Background Patients undergoing vascular surgery comprise the highest risk group for perioperative cardiac mortality and morbidity after noncardiac procedures. Many current guidelines recommend the use of β-blockers in all patients undergoing vascular surgery. We report a trial of the perioperative administration of metoprolol and its effects on the incidence of cardiac complications at 30 days and 6 months after vascular surgery. Methods Patients undergoing abdominal aortic surgery and infrainguinal or axillofemoral revascularizations were recruited to a double-blind randomized controlled trial of perioperative metoprolol versus placebo. Patients were randomized to receive study medication, starting 2 hours preoperatively until hospital discharge or maximum of 5 days postoperatively. Primary outcome were postoperative 30-day composite incidence of nonfatal myocardial infarction, unstable angina, new congestive heart failure, new atrial or ventricular dysrhythmia requiring treatment, or cardiac death. Results Patients were randomized to receive either metoprolol (n = 246) or placebo (n = 250). Primary outcome events at 30 days postoperative occurred in 25 (10.2%) versus 30 (12.0%) (P = .57) in metoprolol and placebo groups, respectively (relative risk reduction 15.3%, 95% CI −38.3% to 48.2%). Observed effects at 6 months were not significantly different (P = .81) (relative risk reduction 6.2%, 95% CI% −58.4% to 43.8%). Intraoperative bradycardia requiring treatment was more frequent in the metoprolol group (53/246 vs 19/250, P = .00001), as was intraoperative hypotension requiring treatment (114/246 vs 84/250, P = .0045). Conclusion Our results showed metoprolol was not effective in reducing the 30-day and 6-month postoperative cardiac event rates. Prophylactic use of perioperative β-blockers in all vascular patients is not indicated.