Randomized double-blind comparison of the effects of isosorbide dinitrate retard, verapamil sustained-release, and their combination on myocardial ischemic episodes

Abstract

The antianginal and anti-ischemic efficacy of isosorbide dinitrate (ISDN) retard 120, verapamil 120 sustained-release (s.r.) and their combination was evaluated in 30 patients with chronic angina pectoris. The study was a randomized, double-blind crossover comparison. The evaluation was determined by exercise testing and 24-hour electrocardiographic ambulatory monitoring. The sum of ST-segment depression at comparable exercise levels was reduced by 37% (p less than 0.001) after verapamil 120 s.r. and by 45% (p less than 0.001) after combination therapy. After ISDN retard 120 the sum of ST-segment depression was also slightly reduced by 18% without attaining statistical significance. Total walking time and time to angina pectoris during treadmill exercise were significantly prolonged after all treatments. The sum of ST-segment depression in the 24-hour Holter ECG was reduced by 46% (p less than 0.001) after verapamil and by 39% (p less than 0.01) after combined therapy. After ISDN retard 120 the mean reduction was 34% (p less than 0.01). In conclusion, the result of the study indicated that ISDN retard 120, verapamil 120 s.r. and a combination of both drugs are effective in reducing the frequency and duration of ischemic episodes in patients with ischemic heart disease.