Carotid ultrasound identifies high risk subclinical atherosclerosis in adults with low framingham risk scores.

BACKGROUND: Worldwide, cardiovascular (CV) disease remains the most common cause of morbidity and mortality. Although effective in predicting CV risk in select populations, the Framingham risk score (FRS) fails to identify many young individuals who experience premature CV events. Accordingly, the aim of this study was to determine the prevalence of high-risk carotid intima-media thickness (CIMT) or plaque, a marker of atherosclerosis and predictor of CV events, in young asymptomatic individuals with low and intermediate FRS (<2% annualized event rate) using the carotid ultrasound protocol recommended by the American Society of Echocardiography and the Society of Vascular Medicine.
METHODS: Individuals aged < or = 65 years not taking statins and without diabetes mellitus or histories of coronary artery disease underwent CIMT and plaque examination for primary prevention. Clinical variables including lipid values, family history of premature coronary artery disease, and FRS and subsequent pharmacotherapy recommendations were retrospectively collected for statistical analysis.
RESULTS: Of 441 subjects (mean age, 49.7 + or - 7.9 years), 184 (42%; 95% confidence interval, 37.3%-46.5%) had high-risk carotid ultrasound findings (CIMT > or = 75th percentile adjusted for age, gender, and race or presence of plaque). Of those with the lowest FRS of < or =5% (n = 336) (mean age, 48.0 + or - 7.6 years; mean FRS, 2.5 + or - 1.5%), 127 (38%; 95% confidence interval, 32.6%-43.0%) had high-risk carotid ultrasound findings. For individuals with FRS < or = 5% and high-risk carotid ultrasound findings (n = 127; mean age, 47.3 + or - 8.1 years; mean FRS, 2.5 + or - 1.5%), lipid-lowering therapy was recommended by their treating physicians in 77 (61%).
CONCLUSIONS: Thirty-eight percent of asymptomatic young to middle-aged individuals with FRS < or = 5% have abnormal carotid ultrasound findings associated with increased risk for CV events. Pharmacologic therapy for CV prevention was recommended in the majority of these individuals. The lack of radiation exposure, relatively low cost, and ability to detect early-stage atherosclerosis suggest that carotid ultrasound for CIMT and plaque detection should continue to be explored as a primary tool for CV risk stratification in young to middle-aged adults with low FRS. Copyright 2010 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.