EFFECTS OF THE SINGLE AND REPEATED ADMINISTRATION OF BENAZEPRIL ON SYSTEMIC AND FOREARM CIRCULATION AND CARDIAC-FUNCTION IN HYPERTENSIVE PATIENTS

The hemodynamic and cardiac effects of the new angiotensin-converting enzyme inhibitor, benazepril, were studied in 28 hypertensives in a do uble blind, placebo-controlled, between-patient study. Hemodynamic stu dies were performed noninvasively by means of M-mode echo (central hem odynamics and left ventricular systolic function), 2-D echo-Doppler (l eft ventricular diastolic function), and pulsed Doppler flowmetry (for earm circulation). Examinations were done at the end of a placebo run- in period and 3 hours after benazepril administration, both on the fir st day and after 6 weeks of treatment (10 or 20 mg once daily, accordi ng to patient response). In comparison with placebo, benazepril reduce d systolic (p = 0.04) and diastolic (p = 0.003) blood pressure, becaus e of a significant reduction in systemic vascular resistance (p = 0.03 ), while cardiac output was unchanged. Forearm vascular resistance was reduced and brachial artery compliance increased, although not to a s tatistically significant level (both p = 0.07). Both systolic and dias tolic left ventricular function were positively influenced by the afte rload reduction: End-systolic stress was reduced by 12% (p = 0.07), as was the late diastolic peak flow velocity (p = 0.02). All hemodynamic changes were evident after acute benazepril administration, and no di fference was observed between acute and repeated treatment. We conclud e that, similar to other ACE-inhibitors, benazepril reduces blood pres sure through a reduction in vascular resistance, while cardiac output and heart rate are unaffected. These hemodynamic effects occur as earl y as after the first administration and exert a favorable influence on left ventricular dynamics.