Effect of isradipine in black patients with very severe hypertension: 24-hour ambulatory blood pressure monitoring and echocardiographic evaluation

Fifty consecutive black patients with very severe hypertension (sitting diastolic blood pressure ≥120 mm Hg and systolic ≥210 mm Hg by the conventional cuff method) were treated in an openlabel study (without a placebo or active drug control group) for 3 months with a long-acting preparation of isradipine (Dynacirc SRO), during which time serial changes in 24-h ambulatory blood pressure monitoring (ABPM), left ventricular (LV) mass index, and LV systolic function were evaluated. Mean 24-h ABPM was reduced from 184 ± 13/119 ± 6 to 148 ± 18/96 ± 11 mm Hg at 3 months (P <.0001). The reduction in BP was sustained for 24 h after dosing. Simultaneous BP measurements using a conventional cuff method and Dinamap were significantly different from the ABPM preand posttherapy, suggesting a marked “white coat” pressor effect. LV mass index regressed from 143 ± 36 to 122 ± 32 g/m2at 3 months (P <.02). Heart rate and mean body weight were unchanged. Left ventricular performance was not adversely affected. Cardiac index and fractional shortening changed insignificantly, from 2.6 ± 0.6 to 2.7 ± 0.5 L/min/m2and from 28 ± 6 to 31 ± 7%, respectively. Adverse effects were few and tended to disappear during the treatment period. All of the clinical laboratory parameters tested remained unchanged. We conclude that in this group of patients long-acting isradipine 1) showed a marked and sustained antihypertensive action demonstrated by 24-h ABPM; and 2) was well tolerated and associated with LV mass regression without adverse effect on systolic cardiac function. Furthermore, had dose titration decisions been based on conventional sphygmomanometry rather than 24-h ABPM, doses would have been markedly higher. One should be aware of this when uptitrating patients with severe hypertension. Am J Hypertens 1994;7:1058–1064. © 1994 by the American Journal of Hypertension, Inc.