LAUSR

Introduction: South Asian ethnicity is associated with increased atherosclerotic cardiovascular disease (ASCVD) risk and has been identified as a “risk enhancer” in the 2018 ACC/AHA Guideline on the Management of Blood Cholesterol. Hypothesis: An increased use of statins has been recommended since implementation of the 2013 ACC/ AHA Pooled Cohort Equation (PCE); however, the impact of statins on ASCVD outcomes in South Asians is not well understood. We aim to identify the accuracy of 10-year ASCVD risk prediction by the PCE, based on statin use, in a South Asian cohort. Methods: This is a retrospective cohort study of members within Kaiser Permanente Northern California without existing ASCVD, age range 30-70, for whom lipid panel, ethnic data, and 10-year follow up were available. ASCVD events were defined as acute myocardial infarction, ischemic stroke, and cardiovascular death. The cohort was stratified by statin use: never, at baseline and follow-up and only during follow-up. Predicted probability of ASCVD, using the PCE were calculated and compared to the observed for each ASCVD risk category: low <5.0%, borderline 5.0-7.5%, intermediate 7.5-<20.0%, and high >=20.0%. Results: A total of 1,835 South Asian patients were included. ASCVD risk was underestimated by the PCE across all risk categories and statin groups. The greatest disparity was seen in the low-risk ASCVD risk group; entire cohort: 1.8 vs 4.9%, p<0.0001; on statin at baseline and follow-up: 2.58 vs 8.43%, p<0.0001; on statin during follow-up only: 2.18 vs 7.77%, p<0.0001; and never on statin: 1.37 vs 2.09%, p=0.1175 (Figure 1). The absolute risk difference in ASCVD outcomes between the cohort never on statins to those on statins during follow up was 0.73%, 3.31%, and 6.67% in the borderline, intermediate, and high-risk groups, respectively. Conclusions: In a large, community-based South Asian cohort, the PCE underestimated risk in South Asians, who were taking statins, in the low ASCVD risk category.