CAC for Risk Stratification Among Individuals With Hypertriglyceridemia Free of Clinical Atherosclerotic Cardiovascular Disease

Abstract

Objectives: In this study, we sought to evaluate whether the coronary artery calcium (CAC) score can enhance current paradigms for risk stratification among individuals with hypertriglyceridemia in primary prevention. The eligibility criteria for icosapent ethyl (IPE) were used as case example.

Background: Recent trials of atherosclerotic cardiovascular disease (ASCVD) risk-reduction therapies for individuals with hypertriglyceridemia without clinical ASCVD restricted enrollment to participants with diabetes or various other risk factors. These criteria were mirrored in the Food and Drug Administration product label for IPE.

Methods: We pooled 2,345 participants with triglycerides 150 to <500 mg/dL (or >178-<500 mg/dL if not on a statin) and without clinical ASCVD from MESA, CARDIA, the Dallas Heart Study, and the Heinz Nixdorf Recall study. We evaluated the incidence of ASCVD events overall, by IPE eligibility (as defined in the product label), and further stratified by CAC scores (0, >0-100, >100). The number needed to treat for 5 years (NNT₅) to prevent 1 event was estimated among IPE-eligible participants, assuming a 21.8% relative risk reduction with IPE. In exploratory analyses, the NNT₅ was also estimated among noneligible participants.

Results: There was marked heterogeneity in CAC burden overall (45% CAC 0; 24% CAC >100) and across IPE eligibility strata. Overall, 17% of participants were eligible for IPE and 11.9% had ASCVD events within 5 years. Among participants eligible for IPE, 38% had CAC >100, and their event rates were markedly higher (15.9% vs 7.2%) and the NNT₅ 2.2-fold lower (29 vs 64) than those of the 25% eligible participants with CAC 0. Among the 83% participants not eligible for IPE, 20% had CAC >100, and their 5-year incidence of ASCVD (13.9%) was higher than the overall incidence among IPE-eligible participants.

Conclusions: CAC can improve current risk stratification and therapy allocation paradigms among individuals with hypertriglyceridemia without clinical ASCVD. Future trials of risk-reduction therapies in hypertriglyceridemia could use CAC >100 to enroll a high-risk study sample, with implications for a larger target population.

Keywords: cardiovascular disease; coronary artery calcium; hypertriglyceridemia; icosapent ethyl; prevention; primary prevention; risk.