Adding coronary artery calcium (CAC) score, the ankle-brachial index (ABI), high-sensitivity C-reactive protein (hsCRP) levels, and family history (FH) of atherosclerotic cardiovascular disease (ASCVD) improves discrimination and classification of risk over the Framingham risk score, albeit to varying degrees. It is unclear whether adding these 4 “nontraditional” cardiovascular risk markers to the 2013 American College of Cardiology/American Heart Association cholesterol guidelines ASCVD risk estimator will improve its discriminative ability.
Yeboah et al assessed the predictive accuracy and improvement in reclassification gained by these additions to the PCE (pooled cohort equation) in participants from MESA (Multi-Ethnic Study of Atherosclerosis).
The PCE was calibrated for 6,814 MESA participants not prescribed statins at baseline, from which 5,185 had complete data and were included in this analysis. The mean age of included participants was 61 years, 53.1% were women, 9.8% had diabetes, and 13.6% were current smokers.
After 10 years, 320 (6.2%) ASCVD events (myocardial infarction, coronary heart disease-related death, or fatal or nonfatal stroke) occurred. In multivariate Cox analysis, CAC score, ABI, and FH were independent predictors of ASCVD events, but not hsCRP. However, while the CAC score modestly improved the Harrell’s C statistic, ABI, hsCRP levels, and FH produced no improvement in the C statistic when added to the cPCE.
The investigators concluded that the CAC score, ABI, and FH were independent predictors of ASCVD events, but only the CAC score modestly improved the discriminative ability of the calibrated PCE compared with the other nontraditional risk markers. These findings need to be verified in other racial and ethnic groups and the utility and cost-effectiveness of using these nontraditional risk markers for improving ASCVD risk assessment need confirmation. “The promise seen with the CAC score requires further study,” noted the authors.
- 1Yeboah J, Young R, McClelland RL, et al (Herrington DM, senior author).Utility of nontraditional risk markers in atherosclerotic cardiovascular disease risk assessment. J Am Coll Cardiol. 2016; 67: 139-47.