Effect of benazepril on endothelial function in previously untreated hypertensive patients. The Working Group of Cardiology of the Academic Committee of Veszprém, Hungary.

The aim of this study was to determine whether angiotensin-converting enzyme inhibitor administration improves the endothelial function of patients with previously untreated essential hypertension. Using high-resolution ultrasonography, we measured the arteria brachialis diameter at rest, during reactive hyperemia (endothelium-dependent flow-mediated dilatation [FMD]), and after sublingual nitroglycerin (endothelium-independent dilatator). Twenty-one previously untreated hypertensive patients participated in the study (13 men, 8 women; mean age, 39.1 +/- 15 years). In the 21 patients, the basal FMD was 5.02% +/- 4.1%. Two hours after the first 10-mg benazepril dose, the FMD was 6.67% +/- 3.9%, and after 1 month of daily 10-mg benazepril administration, the FMD was 5.59% +/- 2.9%. These changes were not significant compared with the baseline value. Nine patients had relatively normal FMD (>5%), whereas the other 12 patients had abnormal FMD (<5%) at baseline. In the latter group, the first 10 mg benazepril produced significant improvement in FMD, from 2.4% +/- 2.5% to 5.08% +/- 2.4% (P < 0.05), but 10 mg benazepril daily for 1 month resulted in no further improvement (4.78% +/- 2.7%) compared with the acute effect. No difference was found between groups with regard to age, gender, blood pressure, blood lipids, and basal arteria brachialis diameter. The previously untreated patients with essential hypertension have endothelial dysfunction, but individual differences were found. The angiotensin-converting enzyme inhibitor treatment improves endothelial function only in those patients who had endothelial dysfunction before the treatment.