Copyright © 1995 by the European Society of Cardiology.
© 1995 The European Society of Cardiology
Effect of metoprolol on death and cardiac events during a 2-year period after coronary artery bypass grafting
THE MACB STUDY GROUPDivision of Cardiology, Sahlgrenska University Hospital Göteborg, Sweden
revised 20 March 1995; accepted 4 April 1995.
Correspondence: Johan Herlitz, Division of Cardiology, Sahlgrenska Hospital, S-413 45 GÖteborg, Sweden
Abstract
PURPOSE: To evaluate the effect of long-term treatment with metoprolol after coronary bypass grafting on death and cardiac events.
METHODS: Patients in western Sweden on whom coronary artery bypass grafting was performed between June 1988 and June 1991 were evaluated for inclusion during the first 3 weeks after surgery. Major exclusion criteria were age >75 years, concomitant valve surgery, traditional contraindications to beta-blockers and unwillingness to participate. Patients were randomized in a double-blind fashion to 100 mg of metoprolollplacebo daily for 2 weeks and thereafter 200 mg daily for 2 years.
RESULTS: Of 2365 patients who were operated on, 967 were randomized to either metoprolol (n=480) or placebo (n=487). Primary end points (death, non-fatal myocardial infarction, unstable angina pectoris, need for coronary artery bypass grafting or percutaneous transluminal angioplasty), were reached by 42 patients in the metoprolol group (8·8%) as compared with 39 in the placebo group (8·0%) (P=0·73). Of all the patients randomized to metoprolol, 34% withdrew from blind treatment prematurely compared with 44% for placebo (P<0·01)
CONCLUSION: Prophylactic treatment with metoprolol over a 2-year period after coronary artery bypass grafting did not reduce death or the development of cardiac events. However, the 95% confidence limits ranged from the possibility of a 30% reduction in events to a 68% increase in events if patients were treated with metoprolol as compared with placebo.
Key Words: Coronary artery bypass grafting • metoprolol • prognosis