Effect of benazepril on myocardial ischaemia in patients with chronic stable angina pectoris.

The anti-ischaemic properties of benazepril, a non-sulfhydryl inhibitor of angiotensin-converting enzyme, were assessed in 20 patients with chronic stable angina pectoris, by repeated exercise tests and repeated 72-h ambulatory electrocardiographic monitoring. The study was a double-blind, placebo-controlled cross-over; 11 patients received benazepril 10 mg b.i.d. and nine received 20 mg b.i.d. All patients had a positive treadmill stress test and at least three ischaemic episodes during 24 h of ambulatory electrocardiographic monitoring. Benazepril at a dose of 10 mg b.i.d. did not improve the exercise duration, the time taken to reach 1 mm ST depression. Similar findings were observed during treatment with 20 mg b.i.d. Benazepril at a dose of 10 mg b.i.d. was ineffective in improving ischaemic parameters during daily activities. However, among the nine patients who received 20 mg b.i.d. the number of ischaemic episodes was reduced from 142 to 103, and the total duration of ischaemic was reduced from 1099 to 531 min. The number of weekly anginal attacks was reduced from 58 to 33, and the weekly sublingual nitroglycerin tablets consumption was reduced from 31 to 14. When the two doses (10 mg and 20 mg) were combined (N = 20), the number of ischaemic episodes was reduced from 314 to 260 (P = 0.074), and the duration of ischaemic was reduced from 3453 to 2514 min (P = 0.072).