A randomized, double-blind trial comparing the effects of amlodipine besylate/benazepril HCl vs amlodipine on endothelial function and blood pressure

Abstract

Evidence suggests that renin-angiotensin-aldosterone system inhibition ameliorates endothelial dysfunction. The authors examined the effect of amlodipine besylate/benazepril HCl combination treatment compared with amlodipine besylate monotherapy in modulating endothelial dysfunction. This multicenter, double-blind, 12-week study randomized 70 hypertensive subjects with at least one other endothelial dysfunction risk factor to amlodipine besylate/benazepril HCl (5/20 mg/d force-titrated to 5/40 mg/d) or amlodipine besylate monotherapy (5 mg/d force-titrated to 10 mg/d). Both the combination and monotherapy produced significant median increases from baseline in percentage flow-mediated vasodilation (2.0% and 1.2%, respectively) and percentage change in percent flow-mediated vasodilation (25% and 16%, respectively). These improvements were numerically larger with combination treatment, but between-group differences did not achieve statistical significance. Reductions in systolic and diastolic blood pressure were significantly greater (P=.0452/P=.0297) with combination treatment (-18.6/-12.3 mm Hg) than with monotherapy (-14.8/-9.1 mm Hg). A highly positive correlation between change in systolic blood pressure and change in percent of flow-mediated vasodilation was demonstrated only for combination treatment.

Figure 1

Patient disposition chart showing the number of eligible subjects, randomized subjects, and completers. *One subject in the combination arm completed all study evaluations but did not return for the final study visit. This subject technically did not complete the study, but was included in the completers population.