This observational, multicenter, retrospective and prospective study aims to evaluate the effect of lomitapide treatment on Major Adverse Cardiovascular Events (MACE) in patients with Homozygous Familial Hypercholesterolemia (HoFH). HoFH is a rare genetic disorder characterized by extremely high levels of LDL cholesterol (LDL-C), leading to an increased risk of early cardiovascular diseases. Lomitapide is an approved medication that lowers LDL-C levels by inhibiting microsomal triglyceride transfer protein (MTP). The study will collect data from patients who have been treated with lomitapide for at least 12 months and will compare the incidence of MACE during the first three years of treatment with the three years before treatment initiation. The study includes data collection from multiple lipid centers across Europe. The primary objective is to assess the impact of lomitapide on MACE, while secondary objectives include evaluating changes in lipid profiles, liver function tests, and lipid-lowering treatments.