Identification of patients with familial hypercholesterolemia in the Russian population using the example of Moscow City and Moscow Region

Abstract

Aim. To estimate the prevalence of familial hypercholesterolemia (FH) in a sample of Moscow city and Moscow region patients with hypercholesterolemia (HCh) based on lipid spectrum and instrumental methods. Material and methods. The study included two samples of patients (age > 18 years), with total cholesterol (TCh) level ≥ 7.5 mmol/l and/or low-density lipoprotein (LDL) cholesterol level ≥ 4.9 mmol/l. First sample (n=60) was included to determine secondary hyperlipidemia frequency in newly diagnosed HCh, with measurement of thyroid hormone, glucose and glycated hemoglobin (HbA1c) levels. Patients of the second sample (n=432) from Russian registry of FH (RuFH) were studied by drug therapy assessment, lipid profile measurements, calculation of FH probability according to Dutch and British criteria, carotids duplex scanning (CDS), cardiac perfusion single-photon emission computed tomography (SPECT/CT) using rest/stress protocol. Results. The incidence of secondary dyslipidemia due to diabetes or hypothyroidism in patients with severe HCh was 18.3%. Monotherapy with atorvastatin (34.2%) or rosuvastatin (31.8%), combined therapy with statins and other lipid-lowering drugs (24.4%) prevails in the structure of lipidlowering therapy in patients with severe HCh. The frequency of "definite" FH according to Dutch criteria in HCh patients was 15.3%, "probable" - 18.1%. Patients with definite FH diagnosis showed higher level of TCh (p < 0.001), LDL cholesterol (p < 0.001), proprotein convertase subtilisin/kexin type 9 (p < 0.001), lower high-density lipoprotein (HDL; p=0.02), and triglycerides (p < 0.001). At that HDL cholesterol levels differed only in patients treated with lipid-lowering drugs. Patients with lipid-lowering therapy had significantly higher values of total stenosis percent, the number of plaques, intima- media complex thickness (p < 0.001). Patients with lipid-lowering therapy with a definite and probable FH diagnosis had significantly worse values of CDS parameters. CDS parameters correlated with age in both therapeutic groups, and with maximal TCh levels in history in lipid-lowering therapy group (p < 0.01). Patients with HCh and established ischemic heart disease showed higher frequency of positive exercise test result, higher values of left ventricle myocardial perfusion heterogeneity and defect severity parameters according to SPECT. Conclusion. Patients with severe HCh and suspected FH in Moscow city and region demonstrate satisfactory awareness, but low adherence to therapy, which is also extremely rarely sufficient to achieve target LDL levels and reduce coronary risks. This leads to early manifestations of atherosclerosis, including characteristic progressive impairments of myocardial perfusion. Despite the ongoing work on primary prevention, it is advisable to recommend sending such patients to specialized clinics for more qualified consultations and selection of optimal lipid-lowering therapy with mandatory further monitoring of its effectiveness.