CAC Score Among Patients Who Meet Statin Trial Criteria
Does a coronary artery calcium (CAC) score add predictive value to patients who would meet trial-based evidence for statin therapy?
Data from the MESA (Multi-Ethnic Study of Atherosclerosis) trial were used for the present analysis. Men and women aged 45-84 years (n = 5,600) without atherosclerotic cardiovascular disease (ASCVD) at baseline were included. Additional excluding criteria included absence of lipid-lowering therapy, or missing information for risk factors at the baseline examination.
Over a 10-year follow-up, 354 ASCVD and 219 hard coronary heart disease (CHD) events occurred. Based on enrollment criteria for seven randomized controlled trials (RCTs) of statin therapy in primary prevention, 73% of MESA participants (91% of those >55 years of age) were eligible for statin therapy according to a trial-based approach. Among those individuals, CAC = 0 was common (44%) and was associated with low rates of ASCVD and CHD (3.9 and 1.7, respectively, per 1,000 person-years). There was a graded increase in event rates with increasing CAC score, and in individuals with CAC >100 (27% of participants), the rates of ASCVD and CHD were 18.9 and 12.7, respectively. Consequently, the estimated number needed to treat (NNT) in 10 years to prevent one event varied greatly according to CAC score. For ASCVD events, the NNT was 87 for CAC = 0 and 19 for CAC >100. For CHD events, the NNT was 197 for CAC = 0 and 28 for CAC >100.
The authors concluded that most MESA participants qualified for trial-based primary prevention with statins. Among the individuals for whom trial-based evidence supports efficacy of statin therapy, CAC = 0 and CAC >100 were common and associated with low and high cardiovascular risks, respectively. This information may guide shared decision making aimed at targeting evidence-based statins to those who are likely to benefit the most.
Based on these results, clinicians may wish to incorporate CAC information into discussions with patients regarding statin eligibility and benefits.
Keywords: Atherosclerosis, Cardiovascular Diseases, Coronary Artery Disease, Diagnostic Imaging, Dyslipidemias, Hydroxymethylglutaryl-CoA Reductase Inhibitors, Lipids, Plaque, Atherosclerotic, Primary Prevention, Risk Factors
< Back to Listings