LDL-cholesterol lowering and clinical outcomes in hypercholesterolemic subjects with and without a familial hypercholesterolemia phenotype: Analysis from the secondary prevention 4S trial

Abstract

Background and aimsTrial evidence for the benefits of cholesterol-lowering is limited for familial hypercholesterolemia (FH) patients, since they have not been the focus of large outcome trials. We assess statin use in coronary artery disease (CAD) subjects with low-density lipoprotein cholesterol (LDL-C) ≥4.9 mmol/L with or without an FH phenotype. MethodsThe 4S trial randomized hypercholesterolemic CAD patients to simvastatin or placebo. We first stratified participants into baseline LDL-C <4.9 and ≥ 4.9 mmol/L; next, based on the DLCN criteria for FH, the latter group was stratified into four subgroups by presence of none, one or both of “premature CAD” and “family history of CAD”. Participants having both are defined as having an FH phenotype. Results2267 and 2164 participants had LDL-C <4.9 and ≥ 4.9 mmol/L, respectively. Mortality endpoints and major coronary events (MCE) were significantly reduced with simvastatin versus placebo in both groups over 5.4 years, but the latter derived greater absolute risk reductions (ARR) (4.1–4.3% for mortality endpoints, versus 2.5–2.8%).LDL-C reductions were similar among the 4 subgroups with levels ≥4.9 mmol/L. Participants with FH phenotype (n = 152) appeared to derive greater relative benefits with simvastatin than the other three subgroups (all-cause death: 84% relative risk reduction, p = 0.046; MCE: 55% reduction, p = 0.0297); statistical interaction was non-significant. Participants with FH phenotype derived greater ARR than any other group with simvastatin versus placebo (all-cause mortality: 6.6% ARR; MCE 13.2%; versus 3.8% and 8.3%, respectively, among participants with LDL-C ≥4.9 mmol/L but without features suggestive of FH). ConclusionsThe FH phenotype appeared to be associated with greater clinical benefits from a given magnitude of LDL-C reduction as compared to individuals without FH phenotype.