Effect of Antihypertensive Treatment on Small Arteries of Patients With Previously Untreated Essential Hypertension

Abstract

Abstract In a double-blind randomized trial, the effects of treatment with an angiotensin-converting enzyme (ACE) inhibitor (perindopril) and a β-blocker (atenolol) on small artery structure were compared in previously untreated essential hypertensive patients. Subjects (diastolic blood pressure ≥100 and ≤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 <.05). Perindopril treatment caused an increase in small artery diameter (231±14 to 274±13 μm, P <.05) and a reduction in the ratio of media thickness to lumen diameter (7.94±0.65% to 5.96±0.42%, P <.05), whereas atenolol had no effect (246±14 to 231±13 μm 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 β-blockers.