Association between hemodynamics in the common carotid artery and severity of carotid atherosclerosis in patients with essential hypertension

Abstract

Background: Carotid intima-media thickness (IMT) and plaque burden evaluated by B-mode ultrasound have been used as relevant indicators for carotid atherosclerosis. This study was aimed to investigate the relationship between hemodynamic parameters in the common carotid artery (CCA) and the severity of carotid atherosclerosis in untreated hypertensive patients. Methods: Carotid IMT and plaque burden were evaluated in bilateral CCA, bifurcations, external and internal carotid arteries using duplex ultrasound in 80 untreated hypertensive patients. The patients were divided into four groups according to plaque burden. Hemodynamic parameters of CCA, including peak and mean circumferential wall tension (CWT), tensile stress (TS), wall shear stress (WSS), and Young's elastic modulus (YEM), were calculated after measurements of internal diameter (ID), IMT, and peak and mean flow velocities of CCA. Arterial stiffness was also assessed using the brachial-ankle pulse wave velocity (baPWV). Results: Age, pulse pressure, creatinine, carotid IMT, and mean TS were shown to have significant differences among the four plaque groups (P < 0.05). Peak CWT and peak TS were also shown to have marginal differences. In univariate analysis, the peak and mean CWT and TS were significantly correlated with plaque score. Stepwise multiple regression analysis showed that carotid IMT, age, and peak CWT were independently associated with plaque score. Conclusions: These results suggest that the CWT and TS of the CCA are associated with the severity of carotid atherosclerosis in untreated hypertensive patients. Hence, the hemodynamics of vessels may contribute to the plaque burden of low-resistance arteries. © 2008 American Journal of Hypertension, Ltd.