A study of carotid artery echography in hypertension

Abstract

The purpose fo the study was to evaluate the prevalence of carotid atherosclerotic lesions in patients with hypertension through the use of echographic imaging and the impact of nocturnal drops in blood pressure (BP) on the lesions through the use of ambulatory BP monitoring. The study enrolled 70 normal subjects as controls, 70 patients with essential borderline hypertension, 70 patients with mild essential hypertension, and 70 patients with isolated systolic hypertension. The hypertensive patients were divided into two groups: dippers, who demonstrated systolic and/or diastolic arterial pressure drops from daytime to nighttime >10%, and nondippers, who comprised the remaining patients. Echography was used to measure the thickness of the myointimal complex. A thickness of ⩾0.95 mm, based on the average of five measurements taken at the level of the common carotid at a distance of 2 to 3 cm from the flow divider, was considered evidence of myointimal thickening. A focal thickening of ⩾2 mm was considered evidence of a carotid plaque. Plaques were classified on the basis of their echoic characteristic (hard, fibrous, mixed, soft, or hemorrhagic) and location (common carotid, carotid bifurcation, or internal or external carotid). In patients with essential borderline and mild hypertension, carotids with myointimal thickening or with one or more plaques were found significantly more frequently than normal carotids compared with normotensive controls. In patients with isolated systolic hypertension, the prevalence of vessel lesions with respect to the control group did not differ significantly from that found in patients with borderline or mild hypertension. In patients with borderline and mild hypertension carotids with one or more plaques were found significantly more frequently than normal carotids in nondippers compared with dippers. The plaques were located more frequently at the level of the common carotid and the carotid bifurcation than at the level of the internal or external carotid. Moreover, they were more often of hard type than of the fibrous, mixed, or soft type.