Plaque area and tissue composition on duplex ultrasonography (DUS) may identify patients at risk for future stroke, and may assess effects of vascular risk-factor modification (by measuring change in plaque area and/or tissue constituents). We correlated these plaque features with vascular risk factors of CREST-2 participants at baseline.

CREST-2 consists of two randomized trials in patients with asymptomatic ≥70% carotid-stenosis comparing intensive medical management (IMM) plus endarterectomy to IMM alone, and IMM plus stenting to IMM alone. Baseline B-mode DUS images from 500 patients underwent standardized image analysis to measure plaque area, grayscale median (GSM), Gray-Weale score, and areas for intraplaque hemorrhage and lipid-core. We computed the parameter estimates (95% confidence intervals) for baseline patient characteristics (age, sex, race, diabetes, smoking, BMI, blood pressure and LDL levels) versus plaque characteristics.   

Areas of the entire plaque, intraplaque hemorrhage and lipid-core, and the grayscale median were 62.3+36.8mm², 5.3±8.9mm², 9.2±8.6mm², and 57.9±29.7, respectively. High-risk plaque features (larger areas for plaque, hemorrhage or lipid, and lower grayscale medians or Gray-Weale scores) occurred in older patients, males, and those with elevated diastolic blood pressure and LDL levels. 

DUS-based computation of plaque geometry and tissue composition is feasible in a randomized trial. Elevated diastolic blood pressure and LDL levels at baseline are associated with high-risk plaque characteristics. These novel findings identify potentially modifiable targets for aggressive treatment to reduce stroke-risk in patients with carotid stenosis.