Comparison of verapamil and nifedipine in the treatment of variant angina pectoris: Preliminary observations in 10 patients

To assess the relative efficacy of verapamil, nifedlpine and placebo in the therapy of patients with variant angina pectoris, 10 such patients (6 men and 4 women, average age 52 years) were treated for 2 month periods with verapamil (mean ± standard deviation 400 ± 80 mg/day in three to six equal doses; range 240 to 480 mg/day), nifediplne (82 ± 31 mg/day in four to six equal doses; range 40 to 160 mg/day) and placebo. Eight of the 10 patients were maintained throughout the study on a stable regimen of oral isosorbide dinitrate (137 ± 56 mg/day in four to six equal doses; range 40 to 200 mg/day). Before the study, all underwent cardiac catheterization: eight had no fixed coronary artery disease, one had single vessel and one had triple vessel disease. Two patients had been resuscitated from sudden cardiac death before the study. Each patient underwent calibrated two channel ambulatory electrocardiographic monitoring for 24 hours during each week of the study. During each 2 month period, the following data were quantitated: (1) chest pains per week, (2) nitroglycerin tablets used per week, (3) required hospitalizations for clinical instability, (4) adverse effects, and (5) episodes of transient S-T segment deviation on ambulatory monitoring. The number of chest pains per week, the number of nttroglycerin tablets used per week and the number of transient S-T segment deviations on calibrated two channel ambulatory electrocardiographic monitoring were similar during treatment with verapamil and nifedipine and less than with placebo. Hospitalization for clinical instability was required in two patients taking placebo and in two taking nifedipine; no patient required hospitalization during treatment with verapamil. Verapamil caused mild constipation in two patients, sinus nodal pauses in one patient and palpitations in one; none of these effects forced a discontinuation or substantial reduction in dosage. In contrast, the dosage of nifedipine was reduced because of induced orthostatic hypotension in two patients, marked pedal edema in one patient and nausea, anorexia and nonorthostatic dizziness in three. Thus verapamil and nifedipine showed similar efficacy in the treatment of variant angina, although nifedipine was associated with more substantial adverse effects than either placebo or verapamil in this small number of patients.