EFFECT OF ANTIHYPERTENSIVE TREATMENT ON CARDIAC AND SUBCUTANEOUS ARTERY STRUCTURE - A COMPARISON BETWEEN CALCIUM-CHANNEL BLOCKER AND THIAZIDE-BASED REGIMENS

The effects of two antihypertensive regimens (isradipine and hydrochlo rothiazide-amiloride) on the ratio between media thickness and lumen d iameter of subcutaneous arteries and on left ventricular mass in essen tial hypertension were compared. Fifty patients, aged 46.3 +/- 8 (mean +/- SD) years, with newly diagnosed or poorly controlled essential hy pertension were randomized to treatment with either isradipine or hydr ochlorothiazide-amiloride. Atenolol and hydralazine were added in both groups as secondary and tertiary drugs, respectively, when needed for normalization of diastolic blood pressure. A subcutaneous gluteal bio psy was taken surgically before medication and again after 9 months of successful antihypertensive treatment. Two small resistance arteries were isolated from each biopsy and mounted in a Mulvany-Halpern isomet ric small vessel myograph. The media thickness-to-lumen diameter ratio (percentage) of the vessels was measured under standardized condition s and meaned. Left ventricular mass (LVM) index was determined by echo cardiography according to the Penn convention. Ten patients were treat ed with isradipine as monotherapy, whereas only one patient was well c ontrolled on diuretics as monotherapy. Mean blood pressure was reduced equally with the two regimens, from 131 +/- 9 mm Hg to 101 +/- 10 mm Hg with the isradipine and from 128 +/- 9 mm Hg to 99 +/- 7 mm Hg with the thiazide/atenolol regimen. LVM decreased significantly in both gr oups by 130 +/- 75 g with the isradipine-based regimen and by 70 +/- 5 3 g with the hydrochlorothiazide/atenolol-based regimen. The reduction of LVM was significantly greater on the isradipine-based regimen than on the thiazide-based regimen (P < .01). There was a significant redu ction of media thickness-to-lumen diameter ratio during treatment with the isradipine-based regimen from 10.9% to 8.8% (P < .01). The reduct ion in the thiazide regimen was from 9.7% to 8.5%, which was not signi ficant (P = .07). The study demonstrated significant reduction of hype rtensive changes in peripheral resistance artery structure during anti hypertensive treatment with an isradipine-based regimen. The thiazide/ beta-blocker-based regimen did not have a significant effect on the ve ssels. Significant reduction of LVM was achieved with both isradipine- based and thiazide/atenolol-based regimens. The reduction of LVM obtai ned with the isradipine-based regimen was significantly greater than t hat of the thiazide/atenolol-based regimen. (C) 1998 American Journal of Hypertension, Ltd.