Carotid ultrasound backscatter analysis in hypertensive and in healthy subjects

The purpose of this study was to evaluate, by integrated backscatter (IBS) analysis, the influence of arterial hypertension on the carotid ultrasound (US) reflectivity and the age-related changes of this parameter. We recruited 20 middle-aged hypertensive patients free from other major cardiovascular risk factors and 20 gender- and age-matched healthy control subjects. An additional 30 healthy subjects, 15 younger than 30 years old and 15 older than 65 years old were also recruited. The "calibrated" IBS (C-IBS) of the left carotid "distant" wall, calculated as the difference between the IBS mean value (62 measurements) of intima-media (IM) complex and the IBS mean value of adventitia (62 measurements), was significantly higher in those with hypertension than in the age-matched controls, but similar between those with hypertension and the elderly subjects. In the 50 healthy subjects, the C-IBS was positively related to age (r = 0.40; p < 0.01) and to carotid IM thickness (r = 0.33; p < 0.05). Our study shows an increased US reflectivity of carotid wall in hypertensive patients and a positive relation of this parameter to age in the healthy population, suggesting that IBS analysis can be an useful tool to detect a vascular change related to hypertension and to aging.