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