Predictive Value of Coronary Artery Calcium Score From Nongated Chest CT Scans Compared With Gated Scans and Incidence of Cardiovascular Events

BACKGROUND: Data on the prognostic value of incidental coronary artery calcium (CAC) from nongated chest computed tomography scans are limited. Using paired computed tomography scans from the MESA (Multi-Ethnic Study of Atherosclerosis) exam 5, we evaluated the relationship between nongated CAC, gated CAC, and future cardiovascular events. METHODS: Between April 2010 and December 2011, a total of 2601 participants underwent same-day gated and nongated chest computed tomography scans. After excluding 106 with previous coronary heart disease or cardiovascular disease and 23 for missing covariates, 2472 participants formed the study population. Gated and nongated scans were interpreted at a core laboratory, blinded to acquisition methodology. Cox regression examined associations between CAC (gated and nongated) and incident coronary heart disease/cardiovascular disease events. Correlation was assessed with Pearson coefficients, model performance with receiver operating characteristic curves and C-statistic, and overall accuracy with Brier scores. RESULTS: Among the 2472 participants, 53% were female, 38% white, 13% Chinese, 26% Black, and 23% Hispanic/Latino. Compared with participants with zero CAC, those with moderate (101–299) and severe (≥300) nongated CAC had higher coronary heart disease risk (hazard ratio, 2.67 [95% CI, 1.14–6.27]; hazard ratio, 5.22 [95% CI, 2.37–11.5]) and cardiovascular disease risk (hazard ratio, 1.32 [95% CI, 1.32–4.04]; hazard ratio, 2.89 [95% CI, 1.68–4.96]). Gated and nongated log-standardized CAC highly correlated ( r =0.961; P