Residual atherosclerotic cardiovascular disease risk in statin-treated adults: The Multi-Ethnic Study of Atherosclerosis

Background Residual atherosclerotic cardiovascular disease (ASCVD) risk in statin-treated US adults without known ASCVD is not well described. Objective To quantitate residual ASCVD risk and its predictors in statin-treated adults. Methods We studied 1014 statin-treated adults (53.3% female, mean 66.0 years) free of clinical ASCVD in the Multi-Ethnic Study of Atherosclerosis. We examined ASCVD event rates by National Lipid Association risk groups over 11-year follow-up and the relation of standard risk factors, biomarkers, and subclinical atherosclerosis measures with residual ASCVD event risk. Results Overall, 5.3% of participants were at low, 12.2% at moderate, 60.3% at high, and 22.2% at very high baseline risk. Despite statin therapy, age- and race-standardized ASCVD rates per 1000 person-years for men and women were both 4.9 for low/moderate risk, 19.1 and 14.2 for high risk, and 35.6 and 26.7 for very high risk, respectively. Specific independent predictors of residual risk included current smoking, family history, diabetes, high-sensitivity C-reactive protein, low-density lipoprotein particle number, carotid intimal medial thickness, and especially coronary artery calcium score. Those on moderate- or high-intensity statins at baseline (compared with low intensity) had 39% lower risks and those who increased statin intensity 62% lower ASCVD event risks (P <.01). Conclusion Residual risk of ASCVD remains high despite statin treatment and is predicted by specific risk factors and subclinical atherosclerosis. These findings may be helpful for identifying those at highest risk needing more aggressive treatment.