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 beta-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 beta-blockers in all vascular patients is not indicated.