Abstract 4364643: Risk Scores Only Weakly Predict Volume of Non-Calcified Coronary Plaque among People with HIV

Abstract

Background/Introduction: Atherosclerotic cardiovascular disease (ASCVD) risk calculators perform poorly among people with HIV (PWH). Non-calcified coronary plaque (NCP) volume measured using coronary computed tomographic angiography (CCTA) predicts future ASCVD events in the general population, and NCP is increased among PWH. However, the ability of ASCVD risk calculators to predict NCP among PWH is unknown. Methods: We included individuals ages 40-79 with treated and suppressed HIV and ≥ 1 additional cardiovascular risk factor besides HIV. We measured blood pressure and fasting lipid panels. CCTA was performed according to standard research protocol and interpreted by a blinded core lab. The primary outcome was non-calcified plaque volume (excluding calcified plaque). We calculated predicted 10-year atherosclerotic ASCVD risk using four equations: Predicting Risk of cardiovascular disease EVENTs (PREVENT), Pooled Cohort Equation (PCE), Data Collection on Adverse Events of Antiretroviral Drugs (DAD-reduced)-an HIV specific calculator, and Framingham. We used linear regression to assess the amount of variation in log-transformed NCP volume explained by each risk prediction equation. Results: We included 81 individuals with mean age of 60 years, 4% female (Table) . The mean total cholesterol, calculated LDL-C, HDL-C, and triglycerides were 190 mg/dl, 113 mg/dl, 49 mg/dl, and 143 mg/dl, respectively. The mean predicted 10-year ASCVD risk was 5.4% using PREVENT, 12.3% using PCE, 11.5% using DAD, and 17.0% using Framingham. Predicted risk with each of the four equations correlated with NCP volume (p<0.01 for each), and predicted risk was higher among those with more plaque with all four ( Table ). However, the proportion of variance in NCP volume explained by each model was low with R 2 values of 16.4%, 11.1%, 11.7%, and 11.1% for PREVENT, PCE, DAD, and Framingham, respectively ( Figure , p<0.01 for each). Among those with <5% calculated 10-year risk (“low risk”), median plaque volume was 69 mm 3 for PREVENT (45 people), 23 mm 3 for PCE (15 people), 14 mm 3 for DAD (11 people), and 8 mm 3 for Framingham (2 people). Conclusions: Both traditional and HIV specific ASCVD risk prediction equations only explain a small amount of the variation in NCP volume among PWH at elevated cardiovascular risk; this finding may underlie the poor performance of these risk calculators to predict cardiovascular events among this high-risk population.