Treatment pattern of familial hypercholesterolemia in Slovakia: Targets, treatment and obstacles in common practice

Detecting familial hypercholesterolemia: An observational study leveraging mandatory universal pediatric total cholesterol screening in Slovakia

BACKGROUND

In Slovakia, a mandatory national universal pediatric total cholesterol (TC) screening program is in place to identify cases of familial hypercholesterolemia (FH). However, the program's effectiveness has not been systematically assessed.

OBJECTIVE

This study aimed to estimate the prevalence of FH among parents of children that had elevated TC levels identified during screening.

METHODS

This prospective, non-interventional, observational study enrolled parents of 11-year-old children who underwent TC screening in 23 selected pediatric outpatient clinics between 2017 and 2018. FH was diagnosed using the Dutch Lipid Clinic Network (DLCN) criteria and targeted next-generation sequencing. The primary objective was to estimate the proportion of children with a TC level of >188 mg/dL (>4.85 mmol/L) who had a parent with a confirmed diagnosis of FH.

RESULTS

A total of 112 parents of 56 children with an elevated TC level were enrolled. Five children (8.9%) had a parent in whom FH was genetically confirmed. Without genetic analysis, all five parents would only be diagnosed with "possible FH" by DLCN criteria. Of parents, 83.9% (n = 94/112) had an low-density lipoprotein cholesterol (LDL-C) level of >116 mg/dL (>3 mmol/L), but only 5.3% (n = 5/94) received lipid-lowering therapy. Among the five parents with genetically confirmed FH, all had an LDL-C level >116 mg/dL (>3 mmol/L), with a mean (±SD) of 191 (±24) mg/dL (4.94 [±0.61] mmol/L). Only two of these parents received lipid-lowering therapy.

CONCLUSIONS

The present study demonstrates the significance of mandatory universal pediatric TC screening in identifying families with FH and other at-risk families in need of lipid-lowering therapy.

Clinical Aspects of Genetic and Non-Genetic Cardiovascular Risk Factors in Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is the most common monogenic metabolic disorder characterized by considerably elevated low-density lipoprotein cholesterol (LDL-C) levels leading to enhanced atherogenesis, early cardiovascular disease (CVD), and premature death. However, the wide phenotypic heterogeneity in FH makes the cardiovascular risk prediction challenging in clinical practice to determine optimal therapeutic strategy. Beyond the lifetime LDL-C vascular accumulation, other genetic and non-genetic risk factors might exacerbate CVD development. Besides the most frequent variants of three genes (LDL-R, APOB, and PCSK9) in some proband variants of other genes implicated in lipid metabolism and atherogenesis are responsible for FH phenotype. Furthermore, non-genetic factors, including traditional cardiovascular risk factors, metabolic and endocrine disorders might also worsen risk profile. Although some were extensively studied previously, others, such as common endocrine disorders including thyroid disorders or polycystic ovary syndrome are not widely evaluated in FH. In this review, we summarize the most important genetic and non-genetic factors that might affect the risk prediction and therapeutic strategy in FH through the eyes of clinicians focusing on disorders that might not be in the center of FH research. The review highlights the complexity of FH care and the need of an interdisciplinary attitude to find the best therapeutic approach in FH patients.

Assessment of Associations Between Serum Lipoprotein (a) Levels and Atherosclerotic Vascular Diseases in Hungarian Patients With Familial Hypercholesterolemia Using Data Mining and Machine Learning

Background and aims: Premature mortality due to atherosclerotic vascular disease is very high in Hungary in comparison with international prevalence rates, though the estimated prevalence of familial hypercholesterolemia (FH) is in line with the data of other European countries. Previous studies have shown that high lipoprotein(a)- Lp(a) levels are associated with an increased risk of atherosclerotic vascular diseases in patients with FH. We aimed to assess the associations of serum Lp(a) levels and such vascular diseases in FH using data mining methods and machine learning techniques in the Northern Great Plain region of Hungary.

Methods: Medical records of 590,500 patients were included in our study. Based on the data from previously diagnosed FH patients using the Dutch Lipid Clinic Network scores (≥7 was evaluated as probable or definite FH), we trained machine learning models to identify FH patients.

Results: We identified 459 patients with FH and 221 of them had data available on Lp(a). Patients with FH had significantly higher Lp(a) levels compared to non-FH subjects [236 (92.5; 698.5) vs. 167 (80.2; 431.5) mg/L, p < .01]. Also 35.3% of FH patients had Lp(a) levels >500 mg/L. Atherosclerotic complications were significantly more frequent in FH patients compared to patients without FH (46.6 vs. 13.9%). However, contrary to several other previous studies, we could not find significant associations between serum Lp(a) levels and atherosclerotic vascular diseases in the studied Hungarian FH patient group.

Conclusion: The extremely high burden of vascular disease is mainly explained by the unhealthy lifestyle of our patients (i.e., high prevalence of smoking, unhealthy diet and physical inactivity resulting in obesity and hypertension). The lack of associations between serum Lp(a) levels and atherosclerotic vascular diseases in Hungarian FH patients may be due to the high prevalence of these risk factors, that mask the deleterious effect of Lp(a).