Abstract P530: Thoracic Aorta and Coronary Artery Calcification and Atherosclerotic Cardiovascular Disease Risk in South Asian Americans

Abstract

Background: South Asian populations have a high risk of atherosclerotic cardiovascular disease (ASCVD). Subclinical atherosclerosis measures, including thoracic aortic calcification (TAC) and coronary artery calcification (CAC), are associated with ASCVD events, and TAC is a stronger predictor in women than men. However, no prior studies have investigated TAC in South Asians. Methods: We examined data from the Mediators of Atherosclerosis in South Asians Living in America (MASALA) study from 2015-2018. TAC and CAC were measured from computerized tomography scans using the Agatston method, and scores were categorized as 0, 1-99, and 100 or greater. Ten-year ASCVD risk was calculated using the 2013 pooled cohort equations, categorized as low, intermediate, or high risk. We determined associations of traditional risk factors with TAC and CAC and used multivariable ordinal logistic regression to examine associations between TAC and CAC with ASCVD risk in stepwise models. Results: Of 958 participants, 30% had TAC scores between 1-99 and 24% had TAC ≥100. TAC and CAC were modestly correlated (r = 0.30). There was a graded prevalence of TAC and CAC scores with levels of ASCVD risk (Figure). Both TAC and CAC were associated with several traditional risk factors; however, only CAC was associated with current smoking, HDL-cholesterol, triglycerides, and diastolic blood pressure. After adjusting for age, gender, and these four additional risk factors, only TAC ≥100 remained associated with ASCVD risk (OR 3.29, 95% CI 1.86 - 2.23), while CAC and TAC <100 were not. The association between TAC and ASCVD risk was stronger for women than men (p-for-interaction <0.001). Conclusion: Though TAC and CAC are associated with traditional risk factors, high TAC levels were independently associated with ASCVD risk, especially among women. Further study is needed to determine whether high TAC scores may be predictive of ASCVD events in South Asian populations.