Prognostic value of coronary artery calcium score for the prediction of atherosclerotic cardiovascular disease in participants with suspected nonalcoholic hepatic steatosis: Results from the multi-ethnic study of atherosclerosis

Background: Nonalcoholic fatty liver disease (NAFLD) is associated with an increased risk of atherosclerotic cardiovascular disease (ASCVD) events; thus, a diagnostic approach to help identify NAFLD patients at high risk is needed. In this study, we hypothesized that coronary artery calcium (CAC) screening could help stratify the risk of ASCVD events in participants with suspected nonalcoholic hepatic steatosis. Methods: A total of 713 participants with suspected nonalcoholic hepatic steatosis without previous cardiovascular events from the Multi-Ethnic Study of Atherosclerosis (MESA) were followed for the occurrence of incident ASCVD. Nonalcoholic hepatic steatosis was defined using nonenhanced computed tomography and liver/spleen attenuation ratio <1. Cox proportional hazards regression models were used to estimate hazard ratios (HR). C-statistics and areas under the time-dependent receiver operating characteristic curves (tAUC) were used to compare incremental contributions of CAC score when added to the clinical risk factors. Results: In multivariable analyses, CAC score was found to be independently associated with incident ASCVD (HR = 1.33, 95% CI = 1.22-1.44, P <.001). The addition of CAC score to clinical risk factors increased the C-statistic from 0.677 to 0.739 (P <.001) and tAUC at 10 years from 0.668 to 0.771, respectively. In subgroup analyses, the incremental prognostic value of CAC score was more significant in participants with low/borderline- (<7.5%) and intermediate- (7.5%-20%) 10–year ASCVD risk scores. Conclusions: The inclusion of CAC score in global risk assessment was found to significantly improve the classification of incident ASCVD events in participants with suspected nonalcoholic hepatic steatosis, indicating a potential role for CAC screening in risk assessment.