Capillary blood cell velocity in finger nailfold: effect of enalapril and mibefradil in patients with mild to moderate hypertension.

Outpatients with essential hypertension were randomized to receive antihypertensive treatment with either mibefradil or enalapril. Ambulatory blood pressure measurement (ABPM) and video capillary microscopy of the finger nailfold were performed at baseline and after 12 weeks of treatment. In the enalapril group (n = 21) baseline ABP was 156 +/- 12/100 +/- 9 mm Hg and decreased to 140 +/- 17/89 +/- 10 mm Hg after 12 weeks. In the mibefradil group (n = 22) mean 24-h ABP decreased from 159 +/- 14/102 +/- 7 to 140 +/- 10/89 +/- 7 mm Hg. Capillary blood cell velocity (CBV) without treatment was 0.90 +/- 0.58 mm/s (mean +/- SD) and 0.83 +/- 0.46 mm/s at rest and 0.30 +/- 0.22 and 0.21 +/- 0.20 mm/s immediately after local finger cooling in the mibefradil and the enalapril group, respectively. In the Enalapril group CBV at week 12 was 0.99 +/- 0. 60 mm/s (n.s.) at rest and 0.40 +/- 0.28 mm/s immediately after local cooling (P = 0.005 compared to 0.21 +/- 0.20 mm/s without treatment). Twelve weeks after initiation of treatment CBV was 0.76 +/- 0.48 mm/s (n.s.) at rest and 0.31 +/- 0.28 mm/s (n.s.) immediately after local cooling in the mibefradil group. Finger nailfold CBV immediately after local finger cooling was increased by enalapril compared to baseline. The T-channel-inhibiting calcium antagonist mibefradil did not change CBV in finger nailfold capillaries.