FAILURE OF PROTECTIVE EFFECT OF CAPTOPRIL AND ENALAPRIL ON EXERCISE AND DIPYRIDAMOLE-INDUCED MYOCARDIAL-ISCHEMIA

Fifteen patients with angiographic evidence of significant coronary ar tery disease, exertional myocardial ischemia, and positive dipyridamol e echocardiographic test results at basal conditions and after 7 days of placebo treatment were prospectively studied to see whether captopr il (containing sulfhydryl) and enalapril (nonsulfhydryl) modify myocar dial ischemia induced by exercise testing and the effects of dipyridam ole echocardiographic testing on regional myocardial contractility, Pa tients were randomized to captopril (150 mg/day in 3 separate doses) o r enalapril (20 mg/day) for 1 week, At the end of this period each pat ient crossed over to the alternate regimen after a washout period of 7 days, Exercise stress testing and dipyridamole echocardiographic test ing were repeated at the end of each treatment period, Neither captopr il nor enalapril had a significantly greater anti-ischemic effect than placebo in any patient, Exercise duration, time to onset of ST-segmen t depression, maximal workload, degree of ST-segment depression, and r ate-pressure product were not affected by either drug, Neither captopr il nor enalapril improved dipyridamole-induced mechanical dysfunction or ST-segment depression.