PREVENT and PCE Models for Estimating ASCVD Risk Stratified by Statin Exposure.

Importance: The Predicting Risk of Cardiovascular Disease Events (PREVENT) equations are an updated model developed to improve on the Pooled Cohort Equation (PCE) for estimating 10-year atherosclerotic cardiovascular disease (ASCVD) risk. These equations facilitate patient-clinician discussions on initiating statin therapy and are used to estimate risk without treatment. However, statin exposure during follow-up was not fully accounted for in the development of these equations. Objective: To assess the performance of the PCE and PREVENT equations in estimating ASCVD, accounting for statin exposure during follow-up. Design, Setting, and Participants: This retrospective cohort study included adults from an integrated health care system with 10-year follow-up data. Adults without diabetes or ASCVD were identified in 2013 and followed-up through December 31, 2023, with analyses performed in January 2025. Main Outcomes and Measures: The primary outcome was incident ASCVD. Estimated risks from PCE and PREVENT equations were compared with observed risks, with discrimination assessed via C statistics. The performance of these equations was evaluated in patient populations stratified by statin exposure during follow-up. Results: Among 193 885 adults (median [IQR] age, 55 [48-63] years; 113 400 [58.5%] women), 6528 experienced an ASCVD event. The C statistic was 0.725 (95% CI, 0.719-0.731) for PCE and 0.723 (95% CI, 0.716-0.729) for PREVENT. In the overall population, regardless of statin exposure, the observed 10-year ASCVD risk was lower than estimated by PCE: 3.6% for individuals with estimated risk of 5% to less than 7.5%, 4.5% for those with estimated risk of 7.5% to less than 10%, and 8.0% for those with estimated risk of 10% or greater. The observed risk more closely aligned with the estimated risk from PREVENT: 5.2% for individuals with estimated risk of 5% to 7.5%, 8.1% for those with estimated risk 7.5% to less than 10%, and 11.6% for those with estimated risk of 10% or greater. In contrast, among patients not exposed to statin therapy during follow-up, PREVENT underestimated risk: observed risk was 8.2% for individuals with estimated risk of 5% to less than 7.5%, and 13.5% for those with estimated risk of 7.5% to less than 10%, while PCE-estimated risk more closely approximated the observed risk. Conclusions and Relevance: In this retrospective cohort study, the PREVENT model underestimated risk in patients not treated with statins, whereas the PCE estimates more closely reflected what a patient's risk would be without statin therapy.