Long-term efficacy of diltiazem assessed with multistage graded exercise tests in patients with chronic stable angina pectoris.

The long-term efficacy of diltiazem, 360 mg/day, in patients with grade II or III stable exertional angina pectoris (Canadian Cardiovascular Society criteria) was assessed by multistage graded exercise tests. Seventeen patients undertook a placebo-controlled, double-blind, dose-titration protocol and all received long-term therapy. Exercise tests were performed at the end of 2 weeks of placebo treatment and after 6, 18, 26, 40 and 52 weeks of diltiazem, 360 mg/day. All patients had angina during treadmill testing with placebo and the mean (+/- standard error of the mean) exercise time was 5.8 +/- 0.7 minutes. This increased to 10.8 +/- 1.0 minutes after 6 weeks, 11.3 +/- 1.1 minutes after 18 weeks, 11.4 +/- 1.1 minutes after 26 weeks, 12.9 +/- 1.2 minutes after 40 weeks and 11.6 +/- 1.3 minutes after 52 weeks of continuous diltiazem therapy (p less than 0.001 vs placebo at all stages). Four patients were withdrawn after 26 weeks of treatment; one patient underwent coronary artery bypass surgery and 3 patients required the addition of beta-adrenoreceptor blocking agents. In 1 patient an irritant rash developed on the torso, legs and arms after 39 weeks of diltiazem and disappeared after discontinuing the drug. One patient complained of swelling and stiffness of the fingers and 3 patients complained of shoulder and elbow pain. Another patient had a myocardial infarction after 8 weeks of diltiazem treatment and died. No other adverse effects were observed during this study.(ABSTRACT TRUNCATED AT 250 WORDS)