Background: Coronary artery calcium (CAC) has been shown in multiple populations to predict atherosclerotic cardiovascular disease. However, its predictive value in Asian-Americans is poorly described.
Patients and methods: We studied 1621 asymptomatic Asian-Americans in the CAC Consortium, a large multicenter retrospective cohort. CAC was modeled in categorical (CAC = 0; CAC = 1-99; CAC = 100-399; CAC ≥ 400) and continuous [ln (CAC + 1)] forms. Participants were followed over a mean follow-up of 12 ± 4 years for coronary heart disease (CHD) death, cardiovascular disease (CVD) death, and all-cause mortality. The predictive value of CAC for individual outcomes was assessed using multivariable-adjusted Cox regression models adjusted for traditional cardiovascular risk factors and reported as hazard ratios (95% confidence interval).
Results: The mean (SD) age of the population was 54 (11.2) years and 64% were men. The mean 10-year atherosclerotic cardiovascular disease risk score was 8%. Approximately half had a CAC score of 0, whereas 22.5% had a CAC score of greater than 100. A total of 56 deaths (16 CVD and 8 CHD) were recorded, with no CVD or CHD deaths in the CAC = 0 group. We noted a significantly increased risk of CHD [hazard ratio (HR): 2.6 (1.5-4.3)] and CVD [HR: 2.3 (1.8-2.9)] mortality per unit increase in In (CAC + 1). Compared to those with CAC scores of 0, individuals with CAC scores of at least 400 had over a three-fold increased risk of all-cause mortality [HR: 3.3 (1.3-8.6)].
Conclusion: Although Asian-Americans are a relatively low-risk group, CAC strongly predicts CHD, CVD, and all-cause mortality beyond traditional risk factors. These findings may help address existing knowledge gaps in CVD risk prediction in Asian-Americans.