Abstract 9425: Coronary Artery Calcium Measurement and Prediction of Cardiovascular Disease by Different Ct Scanner Types: The Multi-Ethnic Study of Atherosclerosis

Introduction: Coronary artery calcium (CAC) scoring is a powerful tool for cardiovascular disease (CVD) risk prediction. The Agatston score weighs lesion area upward for density, and is consistent across computed tomography (CT) scanner type. Considering volume and density separately improves risk prediction, but has not been evaluated by CT scanner type. Hypothesis: Our hypothesis was that the predictive value of volume and density scoring would be superior to the Agatston score across CT scanner types. Methods: We used data from MESA (Multi-Ethnic Study of Atherosclerosis), a prospective cohort study of participants free of baseline clinical cardiovascular disease. CAC was measured using either EBCT (electron beam CT) or MDCT (multi-detector CT). We compared risk prediction for coronary heart disease (CHD) and CVD events using the Agatston method and the volume and density scores by scanner type using Cox proportional hazards models with multivariable adjustment among those with baseline CAC > 0. HRs are presented as per standard deviation. Results: The 3,362 MESA participants with CAC >0 were studied. Using the Agatston method, the HR [95% CI] for CHD was 1.28 [1.16-1.42] for EBCT and 1.22 [1.12-1.34] for MDCT. Using the volume score adjusted for density, the HR for CHD was 2.11 [1.70-2.63] for EBCT and 1.71 [1.41-2.07] for MDCT. Density was strongly and inversely associated with CHD. Similar results were seen for CVD risk and in analyses stratified by sex, BMI, age, and baseline statin use. The volume score demonstrated higher areas under the curve (AUC) than the Agatston score with EBCT (0.702, 95% CI 0.665-0.738 vs 0.677, 95% CI 0.638-0.715, p=0.013) and MDCT (0.669, 95% CI 0.632-0.705 vs 0.653, 95% CI 0.616-0.690, p=0.107). Conclusions: Compared with the Agatston score, the CAC volume score, adjusted for density, provides better risk prediction for CHD and CVD events, regardless of CT scanner type. CAC density was strongly and inversely associated with CVD risk.