title: The effects of perioperative beta-blockade: results of the Metoprolol after Vascular Surgery (MaVS) study, a randomized controlled trial.
abstract: 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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Anesthesiology, University of Ottawa, Ottawa, Canada.
authors.forename: Homer
authors.initials: H
authors.lastname: Yang
authors.forename: Karen
authors.initials: K
authors.lastname: Raymer
authors.forename: Ron
authors.initials: R
authors.lastname: Butler
authors.forename: Joel
authors.initials: J
authors.lastname: Parlow
authors.forename: Robin
authors.initials: R
authors.lastname: Roberts
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage*; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008790:Metoprolol / Q000008:administration & dosage*; D008875:Middle Aged; D019990:Perioperative Care; D014656:Vascular Surgical Procedures / Q000009:adverse effects*
chemical_list: D000319:Adrenergic beta-Antagonists; D008790:Metoprolol