UCLA

Presence of coronary artery calcium (CAC), carotid plaque, and increased carotid intima-media thickness (IMT) may indicate elevated cardiovascular disease (CVD) risk; however, no large studies have compared them directly. This study compares predictive uses of CAC presence, carotid artery plaque presence, and high IMT for incident CVD events. Participants were from the Multi-Ethnic Study of Atherosclerosis (MESA). Predictive values of carotid plaque, IMT, and CAC presence were compared using Cox proportional hazards models, c-statistics, and net reclassification indices. The 6779 participants were mean (SD) 62.2 (10.2) years old; 49.9% had CAC, and 46.7% had carotid plaque. The mean left and right IMT were 0.754 (0.210) mm and 0.751 (0.187) mm, respectively. After 9.5 years (mean), 538 CVD events, 388 coronary heart disease (CHD) events, and 196 stroke/transient ischemic attacks were observed. CAC presence was a stronger predictor of incident CVD and CHD than carotid ultrasound measures. Mean IMT≥75th percentile (for age, sex, and race) alone did not predict events. Compared with traditional risk factors, c-statistics for CVD (c=0.756) and CHD (c=0.752) increased the most by the addition of CAC presence (CVD, 0.776; CHD, 0.784; P<0.001) followed by carotid plaque presence (CVD, c=0.760; CHD, c=0.757; P<0.05). Compared with risk factors (c=0.782), carotid plaque presence (c=0.787; P=0.045) but not CAC (c=0.785; P=0.438) improved prediction of stroke/transient ischemic attacks. In adults without CVD, CAC presence improves prediction of CVD and CHD more than carotid plaque presence or high IMT. CAC and carotid ultrasound parameters performed similarly for stroke/transient ischemic attack event prediction.