Metoprolol treatment for two years after coronary bypass grafting: effects on exercise capacity and signs of myocardial ischaemia.
OBJECTIVE
To evaluate whether prophylactic treatment with metoprolol for two years after coronary artery bypass grafting improves working capacity and reduces the occurrence of myocardial ischaemia in patients with coronary artery disease.


METHODS
After coronary artery bypass grafting, patients were randomised to treatment with metoprolol or placebo 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 median exercise capacity was 140 W in the metoprolol group (n = 307) and 130 W in the placebo group (n = 311) (P > 0.20). An ST depression of > or = 1 mm at maximum exercise was present in 34% of the patients in the metoprolol group and 38% in the placebo group (P > 0.20) and an ST depression of > or = 2 mm at maximum exercise was present in 11% in the metoprolol group and 16% in the placebo group (P = 0.09). The median values for maximum systolic blood pressure were 200 mm Hg in the metoprolol group and 210 mm Hg in the placebo group (P < 0.0001), while the median values for maximum heart rate were 126 beats/min in the metoprolol group and 143 beats/min in the placebo group (P < 0.0001). The occurrence of cardiac and neurological clinical events two years postoperatively among exercised patients was comparable in the treatment groups.


CONCLUSIONS
Treatment with metoprolol for two years after coronary artery bypass grafting did not significantly change exercise capacity or electrocardiographic signs of myocardial ischaemia.
Sjöland
H
H
Division of Cardiology, Sahlgrenska University Hospital, Göteborg, Sweden.
Caidahl
K
K
Lurje
L
L
Hjalmarson
A
A
Herlitz
J
J
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000368:Aged; D001026:Coronary Artery Bypass; D004311:Double-Blind Method; D004562:Electrocardiography; D005080:Exercise Test; D017079:Exercise Tolerance / Q000187:drug effects; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000627:therapeutic use*; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology / Q000517:prevention & control*; D017202:Myocardial Ischemia / Q000503:physiopathology / Q000517:prevention & control; D011184:Postoperative Period
D000319:Adrenergic beta-Antagonists; D008790:Metoprolol