Homozygous familial hypercholesterolemia in Spain. Data from Registry of the Spanish Atherosclerosis Society.

Homozygous familial hypercholesterolemia (HoFH) is a rare disease characterized by the presence of two pathogenic variants in the LDLR, APOB, PCSK9 or LDLRAP1 genes, which cause very high levels of LDL cholesterol and premature atherosclerotic cardiovascular disease (ASCVD).The objective of this study is to analyze the current situation regarding diagnosis, cardiovascular disease, lipid-lowering treatment and degree of control of lipids in patients with HoFH in the National Dyslipidemia Registry of the Spanish Atherosclerosis Society.

Methods: Subjects with HoFH, confirmed by the presence of two pathogenic variants in the genes mentioned above, included in the registry from 2013 to June 2023 with an updated review were analyzed.

Results: 71 HoFH subjects were included. 40.8% were women, aged 52 [24-62] years, 57 adults and 13 children. The median follow-up was 7 [4-13] years. Age of diagnosis was 14 [2-26] years, with 10% of ASCVD at diagnosis and 27% of current ASCVD at 40.6 (13.4) years of age. 38% were on PCSK9i, 9 patients on lomitapide, 9 on LDL apheresis and 1 patient on evinacumab. Subjects with more than 4 therapies achieved >80% reduction in LDLc. In the last visit, the median LDLc was 139.3 [89.4-204.2] mg/dL. ASCVD was strongly associated with male sex and family history of ASCVD, relative risk 5.26 (1.53-18.10) and 2.53 (1.03-6.26), p<0.05, respectively. Only 18% and 10% meet the recommended LDLc goal in primary and secondary prevention respectively.

Conclusions: The current situation of HoFH in Spain is better than expected, with marked reductions in LDLc levels with new treatments. In this population, recommended LDLc goals are difficult to achieve despite maximum lipid-lowering therapy. ASCVD has been reduced and delayed by two decades.