Abstract 12773: Computed Tomography Angiography Evaluation of Coronary Plaque Burden in South Asians and Non-Hispanic Whites Over 65 Years of Age

Abstract

Introduction: South Asians (SA) have greater atherosclerotic cardiovascular disease (ASCVD) rates than non-Hispanic whites (NHW). SA ethnicity is a risk factor for cardiovascular disease, according to ACC/AHA guidelines. However, data on pattern of atherosclerosis in SA is limited. This study examines plaque burden in SA using quantitative plaque analysis from coronary CT angiography (CCTA). Methods: This is a cross-sectional study comparing the prevalence of atherosclerosis in SA to that of NHW. We identified 104 South Asians who underwent CCTA and quantitative plaque analysis. We then matched 1:1 with 104 non-Hispanic whites. Age, gender, diabetes, hypertension and smoking were utilized to perform a 1: 1 covariate match. Quantification of coronary plaque was conducted using automated plaque analysis software (Cleerly, NY, NY). Percentage atheroma volume (PAV), which is a measure of total plaque divided by total vessel volume, was calculated for each plaque subtypes. Results: A total of 208 subjects formed the study population. The mean age was 71.2±4.9, 66% being male, 38% had DM, 72% reported hypertension, and 10% were past smokers in each group. The SA cohort had significantly higher calcified plaque PAV compared to NHW cohort, median (IQR), 7.6(1.9, 15.5) versus 3.9(1.3, 9.6), (p=0.027). Noncalcified plaque PAV was higher in SA 5.2 (3.0, 7.9) versus 4.5 (2.6,7.2), but not statistically significant (p=0.35). The number of subjects with obstructive disease (&gt50% stenosis) trended higher in the SA cohort (71% of SA versus 60% of NHW) (p=0.08). Conclusions: South Asians had significantly higher calcified plaque PAV and a higher prevalence of obstructive disease compared to the NHW cohort. These results are suggestive of a unique plaque burden and distinctive characteristics in the SA population, which may explain the greater incidence of cardiovascular events and supports the current guidelines.