Effect of antihypertensive treatment on small arteries of patients with previously untreated essential hypertension
Thybo, N.K.; Stephens, N.; Cooper, A.; Aalkjaer, C.; Heagerty, A.M.; Mulvany, M.J.
Hypertension 25(4 Pt 1): 474-481
1995
ISSN/ISBN: 0194-911X PMID: 7721386 Document Number: 439786
In a double-blind randomized trial, the effects of treatment with an angiotensin-converting enzyme (ACE) inhibitor (perindopril) and a beta-blocker (atenolol) on small artery structure were compared in previously untreated essential hypertensive patients. Subjects (diastolic blood pressure gtoreq 100 and ltoreq 120 mm Hg) were randomly assigned to treatment for 12 months with either perindopril (n = 13, 4 to 8 mg/d) or atenolol (n= 12, 50 to 100 mg/d); the dosage was adjusted upward and in some cases combined (n=5, perindopril; n=2, atenolol) with thiazide diuretic to achieve target blood pressure (diastolic blood pressure below 90 mm Hg). Before and at the end of treatment, gluteal biopsies were taken under local anesthetic; from these biopsies, two small arteries were dissected and mounted on a myograph for morphometry. The reduction in blood pressure with atenolol (drop in mean blood pressure 28.4 +- 1.8 mm Hg) was greater than with perindopril (20.6 +- 1.8 mm Hg, P lt .05). Perindopril treatment caused an increase in small artery diameter (231 +- 14 to 274 +- 13 mu-m, P lt .05) and a reduction in the ratio of media thickness to lumen diameter (7.94 +- 0.65% to 5.96 +- 0.42%, P lt .05), whereas atenolol had no effect (246 +- 14 to 231 +- 13 mu-m and 7.14 +- 0.47% to 6.79 +- 0.45%, respectively). The change in small artery morphology caused by perindopril was not accompanied by any change in media cross-sectional area, suggesting that the change was due to "remodeling." The results support the possibility that treatment with ACE inhibitors causes a greater normalization of the structure of the resistance vasculature in essential hypertensive patients than treatment with beta-blockers.