Acebultolol: basis for the prediction of effect on exercise tolerance

Twelve unselected males suffering from documented coronary insufficiency and moderately severe angina submitted to graded multistage treadmill exercise testing on 3 separate days, 3.5 hr after a single dose of 0,200, or 400 mg of acebulolol, a cardioselective beta blocker. Control measures included random allocation of 2 patients to each of 6 balanced sequences of administration, standardized double-blind conditions, and variance analysis for Latin-square design with repeated measures on each subject. Performance was evaluated by measuring time elapsed until anginal pain, peak heart rate, peak product of heart rate and blood pressure, and peak oxygen consumption. Mean values for all criteria were significantly atered by 400 mg of acebutolol. Seven out of twelve patients were classified as responders (i.e., exercise duration increased 100% or more). The response after acebutolol was correlated with the performance on placebo in the base of exercise duration, peak heart rate, and peak product of heart rate and blood pressure. It is concluded that: (1) performance criteria are useful predictors of response to beta blockade and (2) acebutolol is a potent antianginal agent when judged by an objective treadmill exercise test.