CAC Scoring Modestly Improves PREVENT ASCVD Risk Prediction

A JAMA study assessed whether coronary artery calcium (CAC) scoring improves risk prediction beyond the PREVENT-ASCVD equations. The longitudinal observational analysis included 6,098 adults aged 45–79 years without baseline ASCVD from six US sites in the Multi-Ethnic Study of Atherosclerosis. Investigators evaluated discrimination, calibration, and reclassification for 10-year fatal and nonfatal ASCVD risk. The study addresses the 2026 multisociety dyslipidemia guideline’s recommendation for selective CAC scoring in patients with estimated risk of 3% to less than 10%.

Participants’ mean age was 61.4 years, 52% were female, and 49% had CAC greater than zero. During 10 years, 366 participants (6%) experienced an ASCVD event. Adding CAC increased the Harrell C statistic from 0.73 by 0.02 (95% CI, 0.01–0.03); categorical net reclassification improvement was 0.095 (95% CI, 0.053–0.137). Among participants with borderline estimated risk, observed event rates were 1.9%, 3.9%, 7.4%, and 14.3% for CAC scores of zero, greater than zero to less than 100, 100 to less than 300, and at least 300, respectively.

Overall improvements were modest, with no change in discrimination and reclassification in some groups. The findings support selective CAC use for borderline to intermediate risk, but this observational prediction study does not establish that CAC-guided management improves clinical outcomes. Only the abstract was available for review.