Alterations of carotid arterial mechanics preceding the wall thickening in patients with hypertension

Abstract

BACKGROUND AND AIMS: Carotid intima-media thickness (cIMT) is an established surrogate marker of atherosclerosis. However, cIMT may not reflect the whole arterial changes occurring in various pathologic conditions, such as hypertension. The aim of this study was to evaluate whether vascular properties of carotid artery (CA) in patients with hypertension differ from those of patients with diabetes and controls before the progression of cIMT. METHODS: Vascular properties of CA were assessed in 402 consecutive asymptomatic subjects who have normal cIMT (131 with hypertension, 151 with diabetes mellitus, and 120 controls). Conventional carotid stiffness indices calculated from vessel diameter and blood pressure, and parameters from velocity-vector imaging (VVI), including vessel area, fractional area change (FAC), radial velocity, circumferential strain, and strain rate were measured to assess the differences between the groups. RESULTS: In univariate analysis, both patients with hypertension and diabetes showed higher elastic modulus, lower distensibility coefficients and FAC of VVI than those of controls. However, when adjusting for baseline covariates, only FAC (odds ratio [OR] = 0.82, 95% confidence interval [CI] = 0.70-0.97, p = 0.025) and vessel area (OR = 2.84, 95% CI = 1.64-4.91, p < 0.001) discriminated CA of patients with hypertension from those of controls. Also, patients with hypertension showed larger vessel area than diabetes (OR = 2.58, 95% CI = 1.75-3.80, p < 0.001) independent of baseline covariates. No significant vascular parameter was found to discriminate patients with diabetes from controls after adjustments. CONCLUSION: Despite normal cIMT, the CA of hypertensive patients was stiffer than those of controls and positive remodeling preceded the wall thickening independent of baseline covariates.