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 < 0.001) after verapamil 120 s.r. and by 45% (p < 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 < 0.001) after verapamil and by 39% (p < 0.01) after combined therapy. After ISDN retard 120 the mean reduction was 34% (p < 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.