Effect of Carotid Plaque Screening Using Contrast-Enhanced Ultrasound on Cardiovascular Risk Stratification

Abstract

Cardiovascular risk stratification of asymptomatic patients is based on the assessment of risk factors. Noninvasive imaging of subclinical atherosclerosis may improve cardiovascular risk stratification, especially in patients with co-morbidities. The aim of this study was to investigate the effect of contrast-enhanced ultrasound (CEUS) of the carotid arteries on cardiovascular risk assessment. The study population consisted of 100 consecutive asymptomatic patients with ≥1 clinical risk factor for atherosclerosis. Cardiovascular risk was estimated by calculating the Prospective Cardiovascular Münster Heart Study (PROCAM) risk score. This score was divided into 3 subgroups: low (≤5%), intermediate (6% to 19%), and high (≥20%). Subclinical carotid atherosclerosis was assessed using standard ultrasound for intima-media thickness and plaque screening and CEUS for additional plaque screening. CEUS was performed using SonoVue contrast agent. Patients with subclinical atherosclerosis were considered to be at high cardiovascular risk. McNemar's test was used to compare PROCAM score to ultrasound findings. The mean PROCAM risk score was 9 ± 10; the PROCAM risk score was low in 72 patients (72%), intermediate in 17 patients (17%), and high in 11 patients (11%). A total of 21 patients (21%) had abnormal carotid intima-media thickness, 77% had plaques on conventional carotid ultrasound, and 88% had plaques on standard carotid ultrasound combined with CEUS. Detection of atherosclerosis led to the reclassification of 79 patients (79%) to high cardiovascular risk (p <0.001). In conclusion, CEUS changes the risk category as estimated by a traditional risk stratification model in most asymptomatic patients. CEUS may thus be an additional method for cardiovascular risk prediction in patient groups with co-morbidities.