METOPROLOL TREATMENT FOR 2 YEARS AFTER CORONARY-BYPASS GRAFTING - EFFECTS ON EXERCISE CAPACITY AND SIGNS OF MYOCARDIAL-ISCHEMIA

Objective-To evaluate whether prophylactic treatment with metoprolol f or two years after coronary artery bypass grafting improves working ca pacity and reduces the occurrence of myocardial ischaemia in patients with coronary artery disease. Methods-After coronary artery bypass gra fting, patients were randomised to treatment with metoprolol or placeb o for two years. Two years after randomisation, a computerised 12-lead electrocardiogram was obtained during a standardised bicycle exercise test in 618 patients (64% of all those randomised). Results-The media n exercise capacity was 140 W in the metoprolol group (n = 307) and 13 0 W in the placebo group (n = 311) (P > 0.20). An ST depression of gre ater than or equal to 1 mm at maximum exercise was present in 34% of t he patients in the metoprolol group and 38% in the placebo group (P > 0.20) and an ST depression of greater than or equal to 2 mm at maximum exercise was present in 11% in the metoprolol group and 16% in the pl acebo group (P = 0.09). The median values for maximum systolic blood p ressure were 200 mm Hg in the metoprolol group and 210 mm Hg in the pl acebo group (P < 0.0001), while the median values for maximum heart ra te were 126 beats/min in the metoprolol group and 143 beats/min in the placebo group (P < 0.0001). The occurrence of cardiac and neurologica l clinical events two years postoperatively among exercised patients w as comparable in the treatment groups. Conclusions-Treatment with meto prolol for two years after coronary artery grafting did not significan tly exercise capacity or electrocardiographic signs of myocardial isch aemia.