Abstract P373: Estimation of Atherosclerotic Cardiovascular Disease Risk in Veterans

There are concerns that 2013 ACC/AHA ASCVD pooled risk prediction models are not accurate predictors in contemporary American patient populations, and that these models do not take into account the highly prevalent use of statin therapy or the effects of statins on vascular disease prevention. Using validated phenotyping algorithms, we evaluated the accuracy of the pooled risk model for the development of Hard ASCVD in 1.42 million Veterans (4.3% women, 16.6% black) with mean age 60 years (range 40-79 years) at baseline VA outpatient clinic evaluations in 2002-2004. There were 93,250 Hard ASCVD events over a mean of 8.4 years of follow up. We estimated Hard ASCVD risk using traditional variables (age, sex, race, total cholesterol, HDL cholesterol, diabetes mellitus, systolic blood pressure, blood pressure treatment, and smoking history) employed in the 2013 ACC/ACC ASCVD risk report. Three analytic approaches were undertaken, using 1) published 2013 ACC/AHA prediction equations, 2) 2013 ACC/AHA variables to fit VA-specific Cox regression models for white men, black men, white women, and black women, and 3) model 2 plus baseline statin use. The Harrell’s c-statistics for the models are shown in the table along with the hazard ratios for statins from model 3. Traditional predictor variables were generally statistically significant in all models, and model 1 over predicted absolute risk of Hard ASCVD in VA by approximately 6%, and statin use was associated with up to an 18% reduction in ASCVD risk. In conclusion, these results demonstrate that the pooled ASCVD prediction model performs relatively well in the VA setting, as shown by relatively good c-statistics. The 2013 ACC/AHA over predicted ASCVD risk and statin therapy at baseline was an important determinant of outcomes.