A five-year follow-up in homozygous familial hypercholesterolemia patients of the Russian familial hypercholesterolemia registry

Background and Aims: Homozygous familial hypercholesterolemia (FH) is a rare genetic condition characterized by markedly elevated low-density lipoprotein cholesterol (LDL-C) concentrations from birth and extreme risk of premature atherosclerotic cardiovascular disease. The aim of this study was to evaluate the effectiveness and adherence to lipid-lowering therapy, the frequency of major adverse cardiovascular events (MACE) in homozygous FH patients during a five-year follow-up within the Russian FH registry. Methods: The study included 17 homozygous FH patients (mean age 22±13 years, 65% females) from the Russian FH registry: 71% (n=12) adults and 29% (n=5) children. Genetic testing was performed in 82% (n=14) subjects: compound heterozygous FH was verified in 11 subjects and true homozygous FH in three persons. MACE included fatal and non-fatal cardiovascular events. Results: The mean age of diagnosis homozygous FH was 10±8 years. Ischemic heart disease was detected in 9 (53%) patients and aortic valve stenosis in 6 (35%) patients. During mean follow-up 74±13 months non-fatal myocardial infarction was registered in two patients and two patients had sudden cardiac death. One patient died due to complications of COVID-19. Initial LDL-C level was 16.1±2.7 mmol/L. During the observation period we found a decrease mean LDL-C level by 29%, none of the patients reached the LDL-C target level. The description of the lipid-lowering treatment is presented in the Table. Three patients were approved for therapy with lomitapide therapy (not registered in the Russia). Conclusions: The using of combined therapy among Russian homozygous FH patients is increased, but new therapeutic agents are needed for better LDL-C levels control.