Carotid intima-media thickness and coronary artery calcium score as indications of subclinical atherosclerosis

OBJECTIVE: To determine the ability of carotid intima-media thickness (CIMT) and coronary artery calcium score (CACS) to detect subclinical atherosclerosis in a young to middle-aged, low-risk, primary-prevention population. PATIENTS AND METHODS: Patients aged 36 to 59 years who underwent determination of CIMT and CACS at our institution between May 1, 2004, and April 1, 2008, were included in the study. Those with diabetes mellitus or a history of coronary, peripheral, or cerebral vascular disease were excluded. Other information, such as Framingham risk score (FRS), was obtained by a review of clinical and laboratory data. RESULTS: Of 118 patients, 89 (75%) had a CACS of zero and 94 (80%) were men; mean ± SD age was 48.9±5.7 years. The mean FRS of this group was 4.0; 86 patients (97%) were considered at low risk (<1% annualized rate) of cardiovascular events. Evidence of carotid atherosclerosis was found in 42 (47%; 95% confidence interval, 37%-58%) of these 89 patients; carotid plaque was found in 30 (34%); and CIMT above the 75th percentile was found in 12 (13%) of age-, sex-, and race-matched control patients. Of the 40 patients with low-risk CIMT (below the 50th percentile), 4 (10%) had a CACS at or above the 50th percentile. CONCLUSION: Subclinical vascular disease can be detected by CIMT evaluation in young to middle-aged patients with a low FRS and a CACS of zero. These findings have important implications for vascular disease screening and the implementation of primary-prevention strategies.