Coronary Artery Calcium Score–Directed Primary Prevention With Statins on the Basis of the 2018 American College of Cardiology/American Heart Association/ Multisociety Cholesterol Guidelines

The 2018 multisociety guidelines on cholesterol management¹ state that the coronary artery calcium (CAC) score can help guide statin therapy in people at intermediate risk for atherosclerotic cardiovascular disease (ASCVD) who are uncertain whether they should take a statin. With a CAC score of 0, a “no statin” approach is reasonable when diabetes mellitus, active smoking, or family history of premature coronary heart disease is absent.¹ Thus, we assessed how CAC score would reclassify statin therapy according to the 2018 guidelines, and the association of CAC score with incident ASCVD, in participants with intermediate 10-year ASCVD risk from the FHS (Framingham Heart Study), for whom the 2013 guidelines would recom-mend statins. We found that CAC score reclassifies one third of intermediate-risk individuals to a “no statin” approach, and that CAC score ≥100th or ≥75th percentile confers a substantially higher risk for ASCVD than CAC score of 0. Specifically, we applied the 2018 guidelines retrospectively to an asymptomatic FHS primary prevention population,² aged 40 to 75 years, with intermediate 10-year ASCVD risk (7.5% to <20%), no prevalent ASCVD, no reported statin use, no diabetes mellitus, no current smoking, low-density lipoprotein cholesterol level of 70 to 189 mg/dL, and computed tomography–based CAC scoring. Participants con-sented to the original study. Secondary use of data was approved by our institutional review board, and informed consent was waived for this post hoc study using existing data. CAC score–guided reclassifica-tion to “no statin” (CAC score, 0) or “initiate statin” (CAC score, ≥100th or ≥75th percentile by age and sex³) was assessed according to the multisociety guidelines. Participants were followed up for a me-dian of 14.7 (quartile 1–quartile 3, 11.7–16.8) years for incident ASCVD, as defined in the Table. Of 389 participants with intermediate ASCVD risk (mean, 57.4 years; 34.4% women), 31.4% (122/389) had CAC score of 0, 28.5% (111/389) had CAC score of 1 to 99 and <75th percentile, and 40.1% (156/389) had CAC score ≥100th or ≥75th percentile. Risk factors were similarly distributed across CAC score strata. To further support the appropriateness of a low-er-risk “no statin” reclassification for participants with a CAC score of 0, incident ASCVD occurred in 4.9% (6/122, including 4 coronary heart disease events) for CAC score of 0, 9.0% (10/111) for CAC score of 1 to 99 and <75th percentile, and 21.2% (33/156) for CAC score ≥100th or ≥75th percentile. Cox proportional.