A controlled trial of verapamil for Prinzmetal's variant angina.

To assess the efficacy and safety of verapamil in variant angina pectoris, we entered 16 patients in a double-blind, randomized trial of nine months, duration. During treatment with verapamil, the frequency of angina fell substantially (12.6 +/- 25.9 chest pains per week with placebo, 1.7 +/- 2.8 pains per week with verapamil, mean +/- S.D.; P less than 0.01), as did the use of nitroglycerin tablets (14.4 +/- 34.4 tablets per week with placebo, 2.1 +/- 3.3 tablets per week with verapamil; P less than 0.05). The number of hospitalizations for clinical instability was significantly lower with verapamil (P less than 0.01). The number of episodes of transient ST-segment deviation during treatment with verapamil was reduced (33.1 +/- 39.3 ST-segment deviations per week with placebo, 7.7 +/- 11.7 deviations per week with verapamil; P less than 0.01). Verapamil caused no side effects forcing a reduction in dosage or a discontinuation. We conclude that verapamil is safe and effective in the therapy of variant angina pectoris.