UC San Diego

Coronary artery calcification (CAC) by the Agatston method predicts cardiovascular disease (CVD), but requires cardiac gated computed tomography (CT) scans, a procedure not covered by most insurance providers. An ordinal CAC score (scored 0-12 based on artery number and extent of calcification involvement) can be measured on standard chest CTs. However, the correlation of ordinal and Agatston CAC scores and their relative association with CVD mortality is uncertain, which we sought to determine. Nested case-control study. Community-living individuals undergoing "whole body" CT scans for preventive medicine. 4,544 consecutive patients with CT scans, were followed from 2000 to 2009. We selected cases who died of CVD (n = 57) and age, sex, and CT slice-thickness matched each case to three controls (N = 171). Cardiac gated 3 mm chest CTs and non-gated 6 mm standard chest CTs. CVD death over 9 years follow-up. The intra- and inter-reader kappa for the ordinal CAC score was 0.90 and 0.76 respectively. The correlation of Agatston and ordinal CAC scores was 0.72 (p < 0.001). In models adjusted for traditional CVD risk factors, the odds of CVD death per 1 SD greater CAC was 1.66 (1.03-2.68) using the ordinal CAC score and 1.57 (1.00-2.46) using the Agatston score. A simple ordinal CAC score is reproducible, strongly correlated with Agatston CAC scores, and provides similar prediction for CVD death in predominantly Caucasian community-living individuals.