Coronary Artery Calcium and Cardiovascular Events in Patients With Familial Hypercholesterolemia Receiving Standard Lipid-Lowering Therapy

Objectives: The aim of this study was to evaluate the role of coronary artery calcium (CAC) as a predictor of atherosclerotic cardiovascular disease (ASCVD) (fatal or not myocardial infarction, stroke, unstable angina requiring revascularization, and elective myocardial revascularization) events in asymptomatic primary prevention molecularly proven heterozygous familial hypercholesterolemia (FH) subjects receiving standard lipid-lowering therapy. Background: FH is associated with premature ASCVD. However, the clinical course of ASCVD in subjects with FH is heterogeneous. CAC score, a marker of subclinical atherosclerosis burden, may optimize ASCVD risk stratification in FH. Methods: Subjects with FH underwent CAC measurement and were followed prospectively. The association of CAC with ASCVD was evaluated using multivariate analysis. Results: A total of 206 subjects (mean age 45 ± 14 years, 36.4% men, baseline and on-treatment low-density lipoprotein cholesterol 269 ± 70 mg/dl and 150 ± 56 mg/dl, respectively) were followed for a median of 3.7 years (interquartile range: 2.7 to 6.8 years). CAC was present in 105 (51%), and 15 ASCVD events (7.2%) were documented. Almost one-half of events were hard outcomes, and the others were elective myocardial revascularizations. The annualized rates of events per 1,000 patients for CAC scores of 0 (n = 101 [49%]), 1 to 100 (n = 62 [30%]) and >100 (n = 43 [21%]) were, respectively, 0, 26.4 (95% confidence interval: 12.9 to 51.8), and 44.1 (95% confidence interval, 26.0 to 104.1). In multivariate Cox regression analysis, log(CAC score + 1) was independently associated with incident ASCVD events (hazard ratio: 3.33; 95% CI: 1.635 to 6.790; p = 0.001). Conclusions: CAC was independently associated with ASCVD events in patients with FH receiving standard lipid-lowering therapy. This may help further stratify near-term risk in patients who might be candidates for further treatment with newer therapies.