Background: There is great need for a simple, noninvasive tool that can be used in an office setting to screen for subclinical atherosclerosis. In patients referred for cardiovascular (CV) risk assessment, we evaluated the ability of ultrasound screening for carotid plaque to identify patients with advanced subclinical atherosclerosis.
Methods: Consecutive asymptomatic patients without vascular disease referred by their physician for measurement of the ankle-brachial pressure index and carotid intima-media thickness (CIMT) were included. Carotid intima-media thickness was measured using the standardized ultrasound protocol from the Atherosclerosis Risk in Communities (ARIC) study. Advanced atherosclerosis was defined as CIMT > or = 75th percentile for age, sex, and race in ARIC.
Results: The mean age of the 327 subjects was 55.4 years (SD 7.7 years). The 10-year Framingham CV risk was 5.1% (4.8%). In a multiple logistic regression model that included Framingham CV risk, ankle-brachial pressure index, and use of lipid-lowering medications, plaque presence significantly predicted advanced atherosclerosis (odds ratio 3.08, 95% CI 1.91-4.96, P < .001). In stepwise regression models that included age, body mass index, current tobacco use, family history of premature CV disease, fasting glucose, sex, systolic blood pressure, total/high-density lipoprotein cholesterol ratio, and use of antihypertensive and lipid-lowering medications, plaque presence independently predicted advanced atherosclerosis (P < .001).
Conclusion: Ultrasound detection of carotid plaque helped identify asymptomatic patients with advanced subclinical atherosclerosis. Screening for carotid plaque is easier than determination of CIMT and may help detect asymptomatic patients at increased CV risk.