Effect of Cumulative Exposure to Low-Density Lipoprotein-Cholesterol on Cardiovascular Events in Patients With Familial Hypercholesterolemia.

BACKGROUND Recent studies suggest that cumulative exposure to low-density lipoprotein-cholesterol (LDL-C) leads to the development of atherosclerotic cardiovascular disease (ASCVD). However, few studies have investigated whether this link extends to individuals with familial hypercholesterolemia (FH), a relevant patient population.Methods and Results:We retrospectively investigated the health records of 1,050 patients with clinical FH diagnosis between April 1990 and March 2019. We used Cox proportional hazards models adjusted for established ASCVD risk factors to assess the association between cholesterol-year-score and major adverse cardiovascular events (MACEs), including death from any cause or hospitalization due to ASCVD events. Cholesterol-year-score was calculated as LDL-C max × [age at diagnosis/statin initiation] + LDL-C at inclusion × [age at inclusion - age at diagnosis/statin initiation]. The median follow-up period for MACE evaluation was 12.3 (interquartile range, 9.1-17.5) years, and 177 patients experienced MACEs during the observation period. Cholesterol-year-score was significantly associated with MACEs (hazard ratio, 1.35; 95% confidence interval, 1.07-1.53; P=0.0034, per 1,000 mg-year/dL), independent of other traditional risk factors including age and LDL-C, based on cross-sectional assessment. Cholesterol-year-score improved the discrimination ability of other traditional risk factors for ASCVD events (C-index, 0.901 vs. 0.889; P=0.00473). CONCLUSIONS Cumulative LDL-C exposure was strongly associated with MACEs in Japanese patients with FH, warranting early diagnosis and treatment initiation in these patients.