UCLA

Background Coronary artery calcium (CAC) predicts cardiovascular disease (CVD) events; however, less is known about how its prognostic implications vary by race/ethnicity. Methods and Results A total of 38 277 whites, 1621 Asians, 977 blacks, and 1349 Hispanics from the CAC Consortium (mean age 55 years, 35% women) were followed over a median of 11.7 years. Modeling CAC in continuous and categorical (CAC=0; CAC 1-99; CAC 100-399; CAC ≥400) forms, we assessed its predictive value for all-cause and CVD mortality by race/ethnicity using Cox proportional hazards and Fine and Gray competing-risk regression, respectively. We also assessed the impact of race/ethnicity on risk within individual CAC strata, using whites as the reference. Models were adjusted for traditional cardiovascular risk factors. Increased CAC was associated with higher total and CVD mortality risk in all race/ethnicity groups, including Asians. However, the risk gradient with increasing CAC was more pronounced in blacks and Hispanics. In Fine and Gray subdistribution hazards models adjusted for traditional cardiovascular risk factors and CAC (continuous), blacks (subdistribution hazard ratio 3.4, 95% confidence interval, 2.5-4.8) and Hispanics (subdistribution hazard ratio 2.3, 95% confidence interval, 1.6-3.2) showed greater risk of CVD mortality when compared with whites, while Asians had risk similar to whites. These race/ethnic differences persisted when CAC=0. Conclusions CAC predicts all-cause and CVD mortality in all studied race/ethnicity groups, including Asians and Hispanics, who may be poorly represented by the Pooled Cohort Equations. Blacks and Hispanics may have greater mortality risk compared with whites and Asians after adjusting for atherosclerosis burden, with potential implications for US race/ethnic healthcare disparities research.