Abstract 9445: Increased Carotid Intima-Media Thickness Compared to Carotid Artery Plaque and Coronary Artery Calcium Presence for Predicting Cardiovascular Disease Events: The Multi-Ethnic Study of Atherosclerosis (MESA)
Background: As a clinical tool, carotid ultrasound can re-classify patients to a higher cardiovascular disease (CVD) risk level when the intima-media thickness (CIMT) is high (≥75th percentile for age, sex, and race) or carotid plaque (CP) is present. No studies have directly compared the predictive utility of CP presence, high common carotid artery IMT, and coronary artery calcium (CAC) presence for incident CVD events in a large, multi-ethnic cohort with extended follow up.
Methods: CVD events (CVD death, coronary heart disease [CHD] and stroke), and transient ischemic attack (TIA) were prospectively assessed in 6,779 MESA participants free of CVD at baseline. CP presence was evaluated and compared to common carotid artery IMT and CAC presence using Cox proportional hazards models, C-statistics and net reclassification indices. Multiple imputation was used to account for missing data.
Results: At baseline, participants were mean (standard deviation) 60.3 (9.4) years old. CAC was present in 49.9% and CP was present in 46.7% subjects. Baseline mean left and right common carotid artery IMT were 0.754 (0.210) mm and 0.751 (0.187) mm. After a median of 8.5 years, 538 CVD events, 388 CHD events and 196 stroke/TIAs were observed. CAC presence was a stronger predictor of CVD, CHD and stroke/TIA than any carotid ultrasound measure (Table). Compared to traditional risk factors, c-statistics for CVD and CHD increased most by the addition of CAC presence (p<0.001) followed by CP presence (CVD, p=0.03; CHD p=0.04). Neither CAC presence nor any carotid measure improved the c-statistic for stroke/TIA (p>0.3). Common carotid artery IMT did not improve the predictive value of CP presence.
Conclusion: CAC presence predicts incident CVD, CHD, and stroke/TIA events better than CP presence, high common carotid artery IMT, or their composite. CAC presence is a better CVD prediction tool than carotid ultrasound measures in healthy, middle-aged adults.
- © 2013 by American Heart Association, Inc.