Abstract 13588: Cardiovascular Outcomes in Patients With Established Atherosclerosis and LDLR Loss of Function: Results From the FOURIER Trial

Abstract

Introduction: Patients with loss of function (LoF) mutations of the LDL receptor gene (LDLR) have lifelong elevations in LDL-C. We investigated their risk of cardiovascular (CV) events compared with patients with intact LDLR function. Methods: We performed a prospective genetic cohort analysis from the FOURIER trial including all 14,297 patients who consented for genetic testing, passed QC, and were of European ancestry. All patients had established ASCVD and were on moderate or high intensity statin therapy. Whole exome sequencing was performed and LoF mutations in LDLR were identified using LOFTEE, a tool for detecting protein-truncating variants. Polygenic risk for CAD was also calculated for each patient using a previously validated 27-SNP genetic risk score, with high and low risk defined as above and below the median. The primary endpoint was a composite of CV death, myocardial infarction, stroke, unstable angina, or coronary revascularization. Results: There were 111 (0.8%) patients identified with an LDLR LoF mutation, representing an approximately 4-fold enrichment compared to the general population. These patients had mean baseline LDL-C levels 62 mg/dl higher than those without an identified LDLR LoF mutation (160 vs. 98 mg/dl, p<0.0001) and a 70% increased risk of CV events (HR 1.70 [1.04-2.79], p=0.03) ( Figure, a ). When polygenic risk for CAD was combined with LDLR mutation status there was a significant gradient of risk identified (p-trend=0.001). Patients without a monogenic LDLR mutation or high polygenic risk had a 2.5-year KM event rate of 8.6%; those with either one had a 10.0-12.9% event rate; those with both had a 17.1% event rate ( Figure, b ). Conclusion: ASCVD patients with LDLR LoF mutations have persistently elevated LDL-C and increased CV risk despite intensive statin therapy. The combination of a monogenic LDLR mutation with high polygenic risk for CAD appears additive in this secondary prevention cohort.