The effect of LDLR-negative genotype on CT coronary atherosclerosis in asymptomatic statin treated patients with heterozygous familial hypercholesterolemia.

OBJECTIVE: To evaluate the influence of LDL receptor (LDLR) -negative mutational status on CT coronary atherosclerosis in asymptomatic statin treated patients with heterozygous familial hypercholesterolemia (FH).
METHODS: Coronary CT angiography (CCTA) was performed in 145 FH patients (93 men; mean age 52 ± 8) screened for LDLR and apolipoprotein B (APOB) mutations. The extent of coronary plaque was compared between two groups: 1) 59 patients (41%) heterozygous for LDLR-negative mutations (LDLR-negative) and 2) 86 patients (59%) with reduced or normal LDLR function (LDLR-positive) consisting of 32 LDLR-defective mutations, 8 APOB mutations and 46 patients in whom no mutation could be identified. The diseased segments score (DSS) was the primary study endpoint defined as the number of coronary artery segments (0-17) with >20% luminal diameter narrowing. We compared the DSS between LDLR-negative and LDLR-positive patients. Within the LDLR-positive group a secondary analysis was performed between identified (LDLR-defective, APOB) and unidentified mutational status.
RESULTS: The median DSS was higher in LDLR-negative than in LDLR-positive patients (4 (1-7) and 2 (0-5); P = 0.017). After adjustment for risk factors, LDLR-negative mutational status remained an independent predictor of the DSS (B = 1.09; P = 0.047). The DSS in the LDLR-positive group was similar for patients with identified and patients with unidentified mutational status.
CONCLUSION: In asymptomatic statin treated patients with a clinical diagnosis of FH, LDLR-negative mutational status is associated with a higher extent of subclinical CT coronary atherosclerosis.