Antihypertensive monotherapy with nisoldipine CC is superior to enalapril in black patients with severe hypertension

A single-center, prospective double-blind randomized trial was conducted to compare the efficacy and safety of the calcium channel blocker nisoldipine in a sustained release coat-core formulation (CC), titrated from 10 mg to 40 mg daily, with the angiotensin converting enzyme inhibitor enalapril, ti trated from 10 to 40 mg daily, in the treatment of black South African pati ents with severe hypertension (sitting diastolic blood pressure [DBP] betwe en 115 and 140 mm Hg, confirmed by 24-h ambulatory blood pressure monitorin g). Treatment target was a sitting DBP < 95 mm Hg by the 9th week of treatm ent. This was followed by a 4-month open phase using nisoldipine CC 10 to 6 0 mg daily. Ninety-six patients had complete data at baseline, and at the e nd of the double-blind and open phases, and were included in this analysis. In both groups, all patients required titration up to the maximal dose of d ouble-blind medication. Monotherapy with nisoldipine CC, but not enalapril, significantly reduced both sitting and 24-h ambulatory blood pressure (BP) . Twenty-four-hour BP in the nisoldipine CC group decreased from 179 +/- 14 /118 +/- 7 to 144 +/- 16/94 -+/- 10 mm Hg (P <.0001) versus 181 +/- 13/117 +/- 5 to 171 +/- 17/ 110 +/- 11 mm Hg in the enalapril group (P = ns). The profound decrease in blood pressure achieved with nisoldipine CC was accomp anied by a significant reduction in left ventricular [LV] mass index, obser ved after only 2 months of treatment (from 146 +/- 40 to 129 +/- 35 g/m(2), P =.05). In contrast, enalapril had no effect on LV mass (from 139 +/- 36 to 142 +/- 50 g/m(2), P = NS). The antihypertensive effect of nisoldipine C C was further demonstrated in the open phase, during which 24-h BP decrease d from 180 +/- 14/118 +/- 6 mm Hg (at baseline) to 142 +/- 16/92 +/- 10 mm Hg at the end of the 16-week open phase (P <.0001). This effect was sustain ed with trough-to-peak ratio of 74% for systolic and 67% for diastolic BP, with further regression in LV mass. Reduction in 24-h systolic BP to < 135 mm Hg was associated with a greater degree of regression of LV mass index i n patients treated with nisoldipine CC. The incidence of adverse events in both groups was low and both nisoldipine CC and enalapril were well tolerat ed. The incidence of significant ventricular arrhythmia was also low and di d not change with treatment. In conclusion, our findings suggest that nisoldipine CC administered once d aily could be considered as a suitable first-line antihypertensive agent in black patients with severe hypertension, based on its profound and sustain ed blood-pressure-lowering effect, associated with significant regression o f left ventricular mass and its low side effect profile. Am J Hypertens 199 9; 12:194-203 (C) 1999 American Journal of Hypertension, Ltd.