958-96 Enalapril Does not Affect Ischemia During Short-term Treatment in Stable Angina Pectoris Irrespective of Its Effect on Blood Pressure

Abstract

Whereas ACE inhibition acutely reduces myocardial ischemia (MI) through neuroendocrine modulation and, after long-term treatment (1 year), affects ischemic events in LV dysfunction. the short-term antiischemic properties in chronic, stable anginal patients and normal LV function are debated. As a pro-ischemic effect may be explained by lowering coronary artery perfusion pressure, the effects of enalapril (E) 10 mg b.i.d. on ischemia in relation to blood pressure (BP), and placebo b.i.d. were compared in 27 patients with chronic exercise-induced angina pectoris in a double-blind cross-over trial with 2 treatment periods of 2 weeks each. Exercise performance was assessed using treadmill exercise tests. No period or treatment sequence effects were observed for BP, heart rate and exercise performance. After treatment with E, resting systolic and diastolic BP were 7% and 6%, respectively, lower compared to placebo. During maximal exercise, systolic BP and ratepressure product (RPP) were similar during both treatments, whereas diastolic BP was 6% less with E. Maximal workload was comparable after both treatment periods. No differences between treatment were seen with regard to exercise duration, time to angina, maximal ST-depression (0.2 mV in both groups) and time to 0.1 mV ST-depression. When patients were divided into 2 groups according to BP response on an initial dose of 10 mg E, 11 pts ≥ 20 mmHg and 16 pts < 16 mmHg, still no differences during exercise were found. Thus, in stable chronic exercise-induced angina, short-term E does not decrease myocardial ischemia, irrespective of first-dose BP response. Also, no pro-ischemic effects as a result of lowering coronary artery perfusion pressure were observed.