EFFECTS OF ANGIOTENSIN-CONVERTING ENZYME-INHIBITION VERSUS BETA-ADRENERGIC-BLOCKADE ON AORTIC STIFFNESS IN ESSENTIAL-HYPERTENSION

We assessed the effects of 6 months of treatment with an angiotensin-c onverting enzyme (ACE) inhibitor (cilazapril) or a beta(1)-adrenergic blocker (atenolol) on aortic stiffness in essential hypertension. Fort y patients (16 women) aged 47 +/- 9 years (mean +/- SD) with baseline systolic and diastolic blood pressures of 162 +/- 15 and 105 +/- 5 mm Hg, respectively, were entered into a double-blind, parallel-group stu dy with cilazapril, 5 mg once daily, or atenolol, 100 mg once daily. T he treatment period was preceded by a 4-week placebo washout phase. Ao rtic elastic modulus (E(p)) was determined by cine magnetic resonance imaging (MRI) and indirect brachial artery blood pressure measurements prior to and after 3 weeks and 6 months of therapy. The reductions in systolic and diastolic blood pressures from baseline to 6 months aver aged -17 +/- 13 and -10 +/- 6 mm Hg, respectively, with cilazapril and -23 +/- 16 and -14 +/- 6 mm Hg with atenolol. Concomitantly, E(p) of the ascending aorta decreased with cilazapril from a median of 2,234 1 0(3)dyn/cm(2) (interquartile range, 866-3,740) to 868 10(3)dyn/cm(2) ( 515-1,486) and with atenolol from a median of 1,611 10(3)dyn/cm(2) (89 5-2,790) to 1,054 10(3)dyn/cm(2) (616-1,860). In repeated-measurements analysis of variance, the change in E(p) with time was statistically significant (p < 0.001) but the group x time interaction was not. We c onclude that 6 months of treatment with either cilazapril or atenolol reduces the stiffness of the ascending aorta in essential hypertension . No statistically significant differences between the effects of the two drugs were observed. The mechanisms and clinical significance of i mproved aortic distensibility with antihypertensive therapy deserve fu rther study.