Algorithm for detection and screening of familial hypercholesterolemia in Lithuanian population.

BACKGROUND: Familial hypercholesterolemia (FH) is one of the most common autosomal dominant diseases. FH causes a lifelong increase in low-density lipoprotein cholesterol (LDL-C) levels, which in turn leads to atherosclerotic cardiovascular disease. The incidence of FH is widely underestimated and undertreated, despite the availability and effectiveness of lipid-lowering therapy. Patients with FH have an increased cardiovascular risk; therefore, early diagnosis and treatment are vital. To address the burden of FH, several countries have implemented national FH screening programmes. The currently used method for FH detection in Lithuania is mainly based on opportunistic testing with subsequent cascade screening of index cases' first-degree relatives. METHODS: A total of 428 patients were included in this study. Patients with suspected FH are referred to a lipidology center for thorough evaluation. Patients who met the criteria for probable or definite FH according to the Dutch Lipid Clinic Network (DLCN) scoring system and/or had LDL-C > = 6.5 mmol/l were subjected to genetic testing. Laboratory and instrumental tests, vascular marker data of early atherosclerosis, and consultations by other specialists, such as radiologists and ophthalmologists, were also recorded. RESULTS: A total of 127/428 (30%) patients were genetically tested. FH-related mutations were found in 38.6% (n = 49/127) of the patients. Coronary artery disease (CAD) was diagnosed in 13% (n = 57/428) of the included patients, whereas premature CAD was found in 47/428 (11%) patients. CAD was diagnosed in 19% (n = 9/49) of patients with FH-related mutations, and this diagnosis was premature for all of them. CONCLUSIONS: Most patients in this study were classified as probable or possible FH without difference of age and sex. The median age of FH diagnosis was 47 years with significantly older females than males, which refers to the strong interface of this study with the LitHir programme. CAD and premature CAD were more common among patients with probable and definite FH, as well as those with an FH-causing mutation. The algorithm described in this study is the first attempt in Lithuania to implement a specific tool which allows to maximise FH detection rates, establish an accurate diagnosis of FH, excluding secondary causes of dyslipidaemia, and to select patients for cascade screening initiation more precisely.

Early Atherosclerosis in Familial Hypercholesterolemia Patients: Significance of Vascular Markers for Risk Stratification.

BACKGROUND: Familial hypercholesterolemia (FH) is a genetic disorder that manifests as impaired low-density lipoprotein cholesterol (LDL-C) metabolism, resulting in lifelong exposure to high cholesterol levels and increased risk of cardiovascular disease (CVD). There is heterogeneity in cardiovascular risk for FH patients, so risk stratification is of utmost importance. The aim of this study was to evaluate the impact of increases in LDL-C and the impact of other CVD risk factors on vascular markers in the FH patient population. METHODS: A total of 428 patients were included in this study and divided into two groups according to age: ≤40 years in the first group and ≥41 years in the second group. Vascular markers of atherosclerosis included the common carotid artery (CCA) intima-media thickness (IMT), pulse wave velocity (PWV), flow-mediated dilation (FMD), ankle-brachial index (ABI), and cardio-vascular index (CAVI). The influence of traditional CVD risk factors on atherosclerotic changes in vascular markers was analyzed. RESULTS: A statistically significant difference in IMT was detected between the same sex and different age groups (p < 0.001), whereas no significant difference was detected between the sexes within each age group. In the ≤40-year-old group, the mean IMT among males was 612.5 µm (±88.2) and that among females was 580.6 µm (±77.7) (p > 0.05); in the ≥41-year-old group, the mean IMT was 697.4 µm (±138.4) for males and 700.3 µm (±114.4) for females (p > 0.05). Higher LDL-C was associated with greater IMT (r = 0.405; p = 0.009) in the younger age group (≤40 years); however, in the older age group (≥41 years), this correlation was not evident (r = -0.07; p = 0.596). Carotid plaque formation was more common among males (OR = 2.2; 95% CI: 1.2-4.0) and hypertensive patients (OR = 2.7; 95% CI: 1.6-4.7). Age was a mildly significant risk factor for increased ABI (ß = 0.13, p < 0.05). FMD was found to be impaired for all patients, and no risk factors were shown to have further influence. Age was a significant risk factor for increased arterial stiffness, as measured by both the CAVI and PWV. CONCLUSIONS: Although vascular markers of atherosclerosis may provide a unique and valuable way to evaluate cardiovascular risk, the results of this study show that only increased IM thickness could be beneficial for risk stratification in young FH patients, whereas other vascular markers of atherosclerosis would be excessive, as they do not provide merit in risk evaluation in this population.