Epidemiology of familial hypercholesterolaemia: Community and clinical

Improving the Detection of Potential Cases of Familial Hypercholesterolemia: Could Machine Learning Be Part of the Solution?

BACKGROUND

Familial hypercholesterolemia (FH), while highly prevalent, is a significantly underdiagnosed monogenic disorder. Improved detection could reduce the large number of cardiovascular events attributable to poor case finding. We aimed to assess whether machine learning algorithms outperform clinical diagnostic criteria (signs, history, and biomarkers) and the recommended screening criteria in the United Kingdom in identifying individuals with FH-causing variants, presenting a scalable screening criteria for general populations.

METHODS AND RESULTS

Analysis included UK Biobank participants with whole exome sequencing, classifying them as having FH when (likely) pathogenic variants were detected in their LDLR, APOB, or PCSK9 genes. Data were stratified into 3 data sets for (1) feature importance analysis; (2) deriving state-of-the-art statistical and machine learning models; (3) evaluating models' predictive performance against clinical diagnostic and screening criteria: Dutch Lipid Clinic Network, Simon Broome, Make Early Diagnosis to Prevent Early Death, and Familial Case Ascertainment Tool. One thousand and three of 454 710 participants were classified as having FH. A Stacking Ensemble model yielded the best predictive performance (sensitivity, 74.93%; precision, 0.61%; accuracy, 72.80%, area under the receiver operating characteristic curve, 79.12%) and outperformed clinical diagnostic criteria and the recommended screening criteria in identifying FH variant carriers within the validation data set (figures for Familial Case Ascertainment Tool, the best baseline model, were 69.55%, 0.44%, 65.43%, and 71.12%, respectively). Our model decreased the number needed to screen compared with the Familial Case Ascertainment Tool (164 versus 227).

CONCLUSIONS

Our machine learning-derived model provides a higher pretest probability of identifying individuals with a molecular diagnosis of FH compared with current approaches. This provides a promising, cost-effective scalable tool for implementation into electronic health records to prioritize potential FH cases for genetic confirmation.

Methylation status of LDLR, PCSK9 and LDLRAP1 is associated with cardiovascular events in familial hypercholesterolemia

Aim: Methylation of LDLR, PCSK9 and LDLRAP1 CpG sites was assessed in patients with familial hypercholesterolemia (FH). Methods: DNA methylation of was analyzed by pyrosequencing in 131 FH patients and 23 normolipidemic (NL) subjects.Results:  LDLR, PCSK9 and LDLRP1 methylation was similar between FH patients positive (MD) and negative (non-MD) for pathogenic variants in FH-related genes. LDLR and PCSK9 methylation was higher in MD and non-MD groups than NL subjects (p < 0.05). LDLR, PCSK9 and LDLRAP1 methylation profiles were associated with clinical manifestations and cardiovascular events in FH patients (p < 0.05).Conclusion: Differential methylation of LDLR, PCSK9 and LDLRAP1 is associated with hypercholesterolemia and cardiovascular events. This methylation profile maybe useful as a biomarker and contribute to the management of FH.

Diagnosis of Familial Hypercholesterolemia in Children and Young Adults

The early detection and treatment of familial hypercholesterolemia (FH) in childhood and adolescence are critical for increasing life expectancy. The purpose of our study was to investigate blood lipid parameters, features of physical signs of cholesterol accumulation, and a personal and family history of premature cardiovascular diseases in children and young adults when FH is diagnosed. The analysis included patients under 18 years of age (n = 17) and young adults (18-44 years of age; n = 43) who received a diagnosis of FH according to clinical criteria. Targeted high-throughput sequencing was performed using a custom panel of 43 genes. A family history of cardiovascular diseases was more often noted in the group under 18 years of age than in young adults (p < 0.001). Among young adults, there was a high prevalence of typical signs of the disease such as tendon xanthomas and the early development of arterial atherosclerosis (p < 0.001). By molecular genetic testing, "pathogenic" and "probably pathogenic" variants were identified in the genes of 73.3% of patients under 18 years of age and 51.4% of patients 18-44 years of age. Thus, blood lipid screening tests combined with an accurate assessment of the family history is a highly relevant and inexpensive option for diagnosing FH in childhood. Molecular genetic testing allows us to make an accurate diagnosis and to improve adherence to treatment.

Gaps in the Care of Subjects with Familial Hypercholesterolemia: Insights from the Thai Familial Hypercholesterolemia Registry

AIMS

Familial hypercholesterolemia (FH) is currently underdiagnosed and undertreated. The establishment of a FH registry could facilitate a deeper understanding of this disease. We described the clinical characteristics of subjects with FH from the Thai FH Registry, compared our data with the regional and global data, and identified gaps in the care of these subjects.

METHODS

A multicenter, nationwide prospective FH registry was established in Thailand. Our data were compared with those of the European Atherosclerosis Society-FH Studies Collaboration. Multiple logistic regression analyses were performed for variables associated with lipid-lowering medication (LLM) use and the attainment of low-density lipoprotein-cholesterol (LDL-C) goal.

RESULTS

The study includes 472 subjects with FH (mean age at FH diagnosis: 46±12 years, 61.4% women). A history of premature coronary artery disease was found in 12%. The percentage of LLM use in subjects with a Dutch Lipid Clinic Network score of ≥ 6 (probable or definite FH) in our registry (64%) was slightly lower than the regional data but higher than the global data. Among those who received statins, 25.2% and 6.4% achieved LDL-C levels of ＜100 mg/dL and ＜70 mg/dL, respectively. Women with FH were less likely to achieve LDL-C ＜70 mg/dL (adjusted odds ratio: 0.22, 95% confidence interval: 0.06-0.71, p=0.012).

CONCLUSIONS

FH in Thailand was diagnosed late, and treatment was inadequate for the majority of subjects. Women with FH were less likely to achieve LDL-C goals. Our insights could potentially help raise awareness and narrow the gap in patient care.

Prevalence and factors associated with possible cases of familial hypercholesterolemia in Brazilian adults: a cross-sectional study

This study aimed to estimate the prevalence of possible cases of FH and analyze associated factors in the adult Brazilian population. Cross-sectional study with laboratory data from the Brazilian National Health Survey, with 8521 participants. Possible cases of FH were defined according to the Dutch Lipid Clinic Network criteria. The prevalence and 95% confidence intervals (95% CI) of possible cases of FH were estimated according to sociodemographic variables, lifestyle, diabetes, hypertension, altered tests, treatment and self-rated health. Logistic regression was used to analyze the associations. The prevalence of possible cases of FH was 0.96%, higher in women, between 45 and 59 years, white race/skin color and others, less education, people with diabetes, hypertension and total cholesterol ≥ 310 mg/dL. The presence of FH was positively associated with regular self-rated health (OR 1.96; 95% CI 0.99-3.84), poor/very poor (OR 3.02; 95% CI 1.30-7.03) and negatively with black race/skin color (OR 0.10; 95% CI 0.02-0.46) and complete elementary school, incomplete high school (OR 0.47; 95% CI 0.23-0.98) and complete high school and more (OR 0.45; 95% CI 0.21-0.95). FH affects 1:104 Brazilian adults, these findings contribute to understanding the burden of disease in Brazil. Due to the scarcity of studies on FH in low- and middle-income countries, further studies are desirable.

Generation and validation of a classification model to diagnose familial hypercholesterolaemia in adults

BACKGROUND AND AIMS

The early diagnosis of familial hypercholesterolaemia is associated with a significant reduction in cardiovascular disease (CVD) risk. While the recent use of statistical and machine learning algorithms has shown promising results in comparison with traditional clinical criteria, when applied to screening of potential FH cases in large cohorts, most studies in this field are developed using a single cohort of patients, which may hamper the application of such algorithms to other populations. In the current study, a logistic regression (LR) based algorithm was developed combining observations from three different national FH cohorts, from Portugal, Brazil and Sweden. Independent samples from these cohorts were then used to test the model, as well as an external dataset from Italy.

METHODS

The area under the receiver operating characteristics (AUROC) and precision-recall (AUPRC) curves was used to assess the discriminatory ability among the different samples. Comparisons between the LR model and Dutch Lipid Clinic Network (DLCN) clinical criteria were performed by means of McNemar tests, and by the calculation of several operating characteristics.

RESULTS

AUROC and AUPRC values were generally higher for all testing sets when compared to the training set. Compared with DLCN criteria, a significantly higher number of correctly classified observations were identified for the Brazilian (p < 0.01), Swedish (p < 0.01), and Italian testing sets (p < 0.01). Higher accuracy (Acc), G mean and F1 score values were also observed for all testing sets.

CONCLUSIONS

Compared to DLCN criteria, the LR model revealed improved ability to correctly classify observations, and was able to retain a similar number of FH cases, with less false positive retention. Generalization of the LR model was very good across all testing samples, suggesting it can be an effective screening tool if applied to different populations.

Genetic Testing for Familial Hypercholesterolemia in a Pediatric Group: A Romanian Showcase

Familial hypercholesterolemia (FH) is a genetic disease marked by high levels of LDL-cholesterol. This condition has long-term clinical implications, such as cardiovascular events, that are evident during adult life. Here, we report on a single-center cross-sectional showcase study of genetic testing for FH in a Romanian pediatric group. Genetic testing for FH was performed on 20 Romanian pediatric patients, 10 boys and 10 girls, admitted with LDL-cholesterol levels over 130 mg/mL to the National Institute for Mother and Child Health "Alesssandrescu-Rusescu" in 2020. Genetic testing was performed using the Illumina TruSight Cardio panel. We identified pathogenic/likely pathogenic variants that could explain the phenotype in 5/20 cases. The involved genes were LDLR and APOB. Clinical signs that suggest the diagnosis of FH are scarce for the pediatric patient, although it can be diagnosed early during childhood by lipid panel screening. Prevention could prove lifesaving for some of these patients.

Referral rate, profile and degree of control of patients with familial hypercholesterolemia: data from a single lipid unit from a Mediterranean area

BACKGROUND

The challenging rigorous management of hypercholesterolemia promotes referral to specialized units. This study explored the need, based on referral rate and cardiovascular (CV) risk factor control in patients evaluated for familial hypercholesterolemia (FH), for a lipid unit (LU).

METHODS

Over a four-year period, 340 referrals to our unit were analyzed to establish the lipid disorder referral rate. Moreover, 118 patients referred for potential FH during the period 2010-2018 (52.4 ± 13.9 years, 47.5% male, Caucasian, 26.3% obese, 33.1% smokers and 51.7% with some glycaemic alteration) were investigated. The Dutch Lipid Clinic Network (DLCN) score, type and dose of lipid-lowering drugs, lipid profile including lipoprotein (a) (Lp(a)) and the presence of plaques with carotid ultrasound (CU) were recorded.

RESULTS

Lipids represented 6.2% of referrals (38 patient-years) requiring a 2-3 h weekly monographic outpatient consultation. The potential FH sample displayed a DLCN score ≥ 6 in 78% and modifiable CV risk factors in 51%. Only 22% achieved tight disease control despite intensive treatment. The statin-ezetimibe combination treatment group achieved better goals (73.0% vs. 45.5%, P = 0.003), and the rosuvastatin group had a higher proportion of prediabetes (60.9% vs. 39.1%, P = 0.037). Neither CU plaque presence nor Lp(a) > 50 mg/dL was linked with established CV disease patients, but higher Lp(a) concentrations were detected between them (102.5 (26.3-145.8) vs. 25.0 (13.0-52.0) mg/dL, P = 0.012).

CONCLUSIONS

The referral rate, degree of control, and proportion of modifiable CV risk factors in FH patients demonstrate the need for LU in our area as well as optimize control and treatment.

Different clinical phenotypes of a pair of siblings with familial hypercholesterolemia: a case report and literature review

BACKGROUND

Familial hypercholesterolemia (FH) leads to high plasma low-density lipoprotein cholesterol (LDL-C) levels and early cardiovascular morbidity and mortality. We treated a pair of siblings with FH. The cardiovascular manifestations in the proband were more severe than those in his elder sister, although they had almost similar LDL-C levels, ages, and lifestyles. Herein, we report the cases of this family to explore the possible causes of clinical phenotypic differences within the same genetic background.

CASE PRESENTATION

We treated a 27-year-old male patient and his 30-year-old sister, both with FH. The coronary angiogram in the male patient revealed 80, 70, and 100% stenosis of the initial, distal right coronary artery branch, and left anterior descending branch, respectively, whereas his sister had almost no coronary stenosis. We treated them accordingly and performed family screening. We found that the LDL-C/particle discordance of the proband is much greater than that of his elder sister. In addition, the average size of LDL-C particle in the proband was smaller than that in his sister.

CONCLUSIONS

Patients with FH have a much higher risk of premature atherosclerotic cardiovascular disease, but the clinical manifestations are heterogeneous. The smaller LDL particle size may be the underlying cause for different clinical outcomes in this pair of FH cases and be a potential novel indicator for predicting the prognosis of FH.

Capacity of HDL to Efflux Cellular Cholesterol from Lipid-Loaded Macrophages Is Reduced in Patients with Familial Hypercholesterolemia

This study aimed to evaluate the high-density lipoprotein (HDL) capacity to efflux cellular cholesterol from lipid-loaded macrophages to find a reliable and low-cost biomarker with the purpose of better evaluating the risk of premature cardiovascular (CV) events in FH patients. This case-controlled study comprised 16 homozygous (HOFH) and 18 heterozygous (HEFH) FH patients, as well as 20 healthy subjects recruited as controls. Two main subfractions of HDL (HDL2 (d = 1.063-1.125 g/mL) and HDL3 (d = 1.125-1.210 g/mL)) were isolated from the patients' serum samples using sequential ultracentrifugation. After compositional characterization, the capacity of HDL to efflux cholesterol (CEC%) from lipid-laden macrophages was measured. The HDL2 and HDL3 subfractions showed some differences in lipid and protein composition between the studied groups. In addition, both HDL subfractions (p < 0.001) revealed significantly reduced CEC% in HOFH patients (HDL2: 2.5 ± 0.1 and HDL3: 3.2 ± 0.2) in comparison with the HEFH (HDL2: 3.2 ± 0.1% and HDL3: 4.1 ± 0.2%) and healthy (HDL2: 3.3 ± 0.2% and HDL3: 4.5 ± 0.3%) subjects. Additionally, multinomial logistic regression results indicated that the CEC% of both HDL2 (OR: 0.091; 95% CI: 0.018-0.452, p < 0.01) and HDL3 (OR: 0.118; 95% CI: 0.035-0.399, p < 0.01) subfractions are strongly and inversely associated with the homozygous form of FH. A decreased capacity of HDL particles to efflux cholesterol from macrophages might identify homozygous FH patients who are at elevated risk for premature CVDs. Prospective studies with a large sample size are warranted to evaluate this hypothesis.

Genetic Spectrum of Familial Hypercholesterolaemia in the Malaysian Community: Identification of Pathogenic Gene Variants Using Targeted Next-Generation Sequencing

Familial hypercholesterolaemia (FH) is caused by mutations in lipid metabolism genes, predominantly in low-density lipoprotein receptor (LDLR), apolipoprotein B (APOB), proprotein convertase subtilisin/kexin-type 9 (PCSK9) and LDL receptor adaptor protein 1 (LDLRAP1). The prevalence of genetically confirmed FH and the detection rate of pathogenic variants (PV) amongst clinically diagnosed patients is not well established. Targeted next-generation sequencing of LDLR, APOB, PCSK9 and LDLRAP1 was performed on 372 clinically diagnosed Malaysian FH subjects. Out of 361 variants identified, 40 of them were PV (18 = LDLR, 15 = APOB, 5 = PCSK9 and 2 = LDLRAP1). The majority of the PV were LDLR and APOB, where the frequency of both PV were almost similar. About 39% of clinically diagnosed FH have PV in PCSK9 alone and two novel variants of PCSK9 were identified in this study, which have not been described in Malaysia and globally. The prevalence of genetically confirmed potential FH in the community was 1:427, with a detection rate of PV at 0.2% (12/5130). About one-fourth of clinically diagnosed FH in the Malaysian community can be genetically confirmed. The detection rate of genetic confirmation is similar between potential and possible FH groups, suggesting a need for genetic confirmation in index cases from both groups. Clinical and genetic confirmation of FH index cases in the community may enhance the early detection of affected family members through family cascade screening.

New Trends and Therapies for Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is associated with an elevated risk of atherosclerosis. The finding of monogenic defects indicates higher atherosclerotic risk in comparison with hypercholesterolemia of other etiologies. However, in heterozygous FH, cardiovascular risk is heterogeneous and depends not only on high cholesterol levels but also on the presence of other biomarkers and genes. The development of atherosclerosis risk scores specific for heterozygous FH and the use of subclinical coronary atherosclerosis imaging help with identifying higher-risk individuals who may benefit from further cholesterol lowering with PCSK9 inhibitors. There is no question about the extreme high risk in homozygous FH, and intensive LDL-cholesterol-lowering therapy must be started as soon as possible. These patients have gained life free of events in comparison with the past, but a high atherosclerosis residual risk persists. Furthermore, there is also the issue of aortic and supra-aortic valve disease development. Newer therapies such as inhibitors of microsomal transfer protein and angiopoietin-like protein 3 have opened the possibility of LDL-cholesterol normalization in homozygous FH and may provide an alternative to lipoprotein apheresis for these patients. Gene-based therapies may provide more definite solutions for lowering high LDL cholesterol and consequent atherosclerosis risk for people with FH.

A mixed methods study of the awareness and management of familial hypercholesterolaemia in Irish general practice

Introduction

Familial Hypercholesterolemia (FH) is one of the most common genetic disorders, with an estimated global prevalence of 1:200-500, which leads to premature cardiovascular disease. Nevertheless, public and professional awareness of FH is often lacking, with an estimated 20,000 largely undiagnosed cases in Ireland.

Purpose

The overall aim of the project was to test the feasibility of a model of care that would include electronic record screening, clinical assessment, and coding of possible FH patients across a network of general practices in Ireland. In addition, a secondary aim was to gauge the awareness and knowledge of FH across the network.

Methods

This study took part in multiple phases, employing a mixed methods design. The study included a validated questionnaire, tailored online educational resources, a retrospective chart review of patients with a history of elevated LDL cholesterol (LDLc) and an active review with a selection of those patients. Results were analyzed using SPSS V27, where descriptive statistics and relevant correlation tests were employed.

Results

Eighteen general practices agreed to take part in the study. In the initial survey, respondents rated their personal and practice familiarity with FH as slightly below average. Around one-third of respondents were not aware of FH guidelines. Of over 55,000 adult patient records searched, only 0.2% had a recorded FH diagnosis and 3.9% had ever had an LDLc above 4.9 mmol/l. Eight practices completed 198 chart reviews. Among these, 29.8% of patients had a family history recorded, and 22.2% had a family history of CVD recorded. Female patients had higher averages for highest and recent LDLc. Seventy patients underwent a clinical review-with 27% of these patients identified as "probable" or "definite FH." There was a statistically significant (p = 0.002) relationship between FH status and whether the patient had other CVD risk factors.

Conclusion

General practitioners in Ireland had similar levels of awareness of FH compared to findings from elsewhere. The activities discussed encouraged clinicians to consider FH when talking to their patients, especially those with elevated LDLc at an early age. Broader awareness of the condition could increase conversations about FH and benefit patient outcomes.

Familial hypercholesterolaemia and coronary risk factors among patients with angiogram-proven premature coronary artery disease in an Asian cohort

BACKGROUND

Familial hypercholesterolaemia (FH) patients have elevated levels of low-density lipoprotein cholesterol, rendering them at high risk of premature coronary artery disease (PCAD). However, the FH prevalence among angiogram-proven PCAD (AP-PCAD) patients and their status of coronary risk factors (CRFs) have not been reported in the Asian population.

OBJECTIVES

This study aimed to (1) determine the prevalence of clinically diagnosed FH among AP-PCAD patients, (2) compare CRFs between AP-PCAD patients with control groups, and (3) identify the independent predictors of PCAD.

METHODS

AP-PCAD patients and FH patients without PCAD were recruited from Cardiology and Specialist Lipid Clinics. Subjects were divided into AP-PCAD with FH (G1), AP-PCAD without FH (G2), FH without PCAD (G3) and normal controls (G4). Medical records were collected from the clinic database and standardised questionnaires. FH was clinically diagnosed using Dutch Lipid Clinic Network Criteria.

RESULTS

A total of 572 subjects were recruited (males:86.4%; mean±SD age: 55.6±8.5years). The prevalence of Definite, Potential and All FH among AP-PCAD patients were 6%(19/319), 16% (51/319) and 45.5% (145/319) respectively. G1 had higher central obesity, family history of PCAD and family history of hypercholesterolaemia compared to other groups. Among all subjects, diabetes [OR(95% CI): 4.7(2.9,7.7)], hypertension [OR(95% CI): 14.1(7.8,25.6)], FH [OR(95% CI): 2.9(1.5,5.5)] and Potential (Definite and Probable) FH [OR(95% CI): 4.5(2.1,9.6)] were independent predictors for PCAD. Among FH patients, family history of PCAD [OR(95% CI): 3.0(1.4,6.3)] and Definite FH [OR(95% CI): 7.1(1.9,27.4)] were independent predictors for PCAD.

CONCLUSION

Potential FH is common among AP-PCAD patients and contributes greatly to the AP-PCAD. FH-PCAD subjects have greater proportions of various risk factors compared to other groups. Presence of FH, diabetes, hypertension, obesity and family history of PCAD are independent predictors of PCAD. FH with PCAD is in very-high-risk category, hence, early management of modifiable CRFs in these patients are warranted.

Developing a Hybrid Risk Assessment Tool for Familial Hypercholesterolemia: A Machine Learning Study of Chinese Arteriosclerotic Cardiovascular Disease Patients

Background

Familial hypercholesterolemia (FH) is an autosomal-dominant genetic disorder with a high risk of premature arteriosclerotic cardiovascular disease (ASCVD). There are many alternative risk assessment tools, for example, DLCN, although their sensitivity and specificity vary among specific populations. We aimed to assess the risk discovery performance of a hybrid model consisting of existing FH risk assessment tools and machine learning (ML) methods, based on the Chinese patients with ASCVD.

Materials and Methods

In total, 5,597 primary patients with ASCVD were assessed for FH risk using 11 tools. The three best performing tools were hybridized through a voting strategy. ML models were set according to hybrid results to create a hybrid FH risk assessment tool (HFHRAT). PDP and ICE were adopted to interpret black box features.

Results

After hybridizing the mDLCN, Taiwan criteria, and DLCN, the HFHRAT was taken as a stacking ensemble method (AUC_class[94.85 ± 0.47], AUC_prob[98.66 ± 0.27]). The interpretation of HFHRAT suggests that patients aged <75 years with LDL-c >4 mmol/L were more likely to be at risk of developing FH.

Conclusion

The HFHRAT has provided a median of the three tools, which could reduce the false-negative rate associated with existing tools and prevent the development of atherosclerosis. The hybrid tool could satisfy the need for a risk assessment tool for specific populations.

Comparative study on the performance of different classification algorithms, combined with pre- and post-processing techniques to handle imbalanced data, in the diagnosis of adult patients with familial hypercholesterolemia

Familial Hypercholesterolemia (FH) is an inherited disorder of cholesterol metabolism. Current criteria for FH diagnosis, like Simon Broome (SB) criteria, lead to high false positive rates. The aim of this work was to explore alternative classification procedures for FH diagnosis, based on different biological and biochemical indicators. For this purpose, logistic regression (LR), naive Bayes classifier (NB), random forest (RF) and extreme gradient boosting (XGB) algorithms were combined with Synthetic Minority Oversampling Technique (SMOTE), or threshold adjustment by maximizing Youden index (YI), and compared. Data was tested through a 10 × 10 repeated k-fold cross validation design. The LR model presented an overall better performance, as assessed by the areas under the receiver operating characteristics (AUROC) and precision-recall (AUPRC) curves, and several operating characteristics (OC), regardless of the strategy to cope with class imbalance. When adopting either data processing technique, significantly higher accuracy (Acc), G-mean and F₁ score values were found for all classification algorithms, compared to SB criteria (p < 0.01), revealing a more balanced predictive ability for both classes, and higher effectiveness in classifying FH patients. Adjustment of the cut-off values through pre or post-processing methods revealed a considerable gain in sensitivity (Sens) values (p < 0.01). Although the performance of pre and post-processing strategies was similar, SMOTE does not cause model’s parameters to loose interpretability. These results suggest a LR model combined with SMOTE can be an optimal approach to be used as a widespread screening tool.

Co-Amorphous Formation of Simvastatin-Ezetimibe: Enhanced Physical Stability, Bioavailability and Cholesterol-Lowering Effects in LDLr-/-Mice

Hypercholesterolemia is one of the independent risk factors for the development of cardiovascular diseases such as atherosclerosis. The treatment of hypercholesterolemia is of great significance to reduce clinical cardiovascular events and patient mortality. Simvastatin (SIM) and ezetimibe (EZE) are commonly used clinically as cholesterol-lowering drugs; however, their treatment efficacy is severely affected by their poor water solubility and low bioavailability. In this study, SIM and EZE were made into a co-amorphous system to improve their dissolution, oral bioavailability, storage stability, and cholesterol-lowering effects. The SIM-EZE co-amorphous solids (CO) were prepared successfully using the melt-quenched technique, and the physicochemical properties of CO were characterized accordingly, which exhibited improved physical stability and faster dissolution release profiles than their physical mixture (PM). In the pharmacokinetic study, the SIM-EZE CO or PM was given once by oral gavage, and mouse blood samples were collected retro-orbitally at multiple time points to determine the plasma drug concentrations. In the pharmacodynamic study, low-density lipoprotein receptor-deficient (LDLr−/−) mice were fed with a high-fat diet (HFD) for two weeks to establish a mouse model of hypercholesterolemia. Using PM as a control, we investigated the regulation of CO on plasma lipid levels in mice. Furthermore, the mice feces were collected to determine the cholesterol contents. Besides, the effect of EZE on the NPC1L1 mRNA expression level in the mouse intestines was also investigated. The pharmacokinetics results showed that the SIM-EZE CO has improved bioavailability compared to the PM. The pharmacodynamic studies showed that SIM-EZE CO significantly increased the cholesterol-lowering effects of the drugs compared to their PM. The total cholesterol excretion in the mouse feces and inhibitory effect on NCP1L1 gene expression in the mouse intestines after being given the SIM-EZE CO were more dramatic than the PM. Our study shows that the SIM-EZE CO prepared by the melt-quenched method can significantly improve the stability, bioavailability, and cholesterol-lowering efficacy with excellent development potential as a new drug formulation.

[Lipoprotein apheresis : State of the art and case report of the longest HELP treatment worldwide]

Lipoprotein apheresis is an extracorporeal procedure for the treatment of patients with homozygous familial hypercholesterolemia, patients with severe treatment-resistant hypercholesterolemia and patients with lipoprotein(a) hypercholesterolemia, who show progressive atherosclerotic cardiovascular disease despite optimal treatment. This article reports on the historical developments of the procedures, the most frequently used methods for apheresis as well as the data situation on efficacy and tolerability. Randomized prospective studies on clinical outcomes are not available. Furthermore, the article reports on a patient with homozygous familial hypercholesterolemia and 34 years of treatment with heparin-induced extracorporeal low-density lipoprotein (LDL) precipitation (HELP) apheresis, the longest treatment of this kind worldwide. A second patient with combined heterozygous familial hypercholesterolemia and 31 years of liposorber and HELP apheresis is also described. The observational studies and the case reports demonstrate the safety and long-term tolerability of the procedure.

Analytical Validation of Familial Hypercholesterolemia Biomarkers in Dried Blood Spots

Heterozygous familial hypercholesterolemia (HeFH) is a common, treatable genetic disorder characterized by premature atherosclerosis and cardiovascular disease, yet the majority of affected individuals remain undiagnosed. Newborn screening could play a role in identification of at-risk individuals and provide an opportunity for early intervention, prior to the onset of symptoms. The objective of this study was to develop and validate assays for quantification of candidate HeFH biomarkers in dried blood spots (DBS). Commercially available enzyme assay kits for quantification of serum total cholesterol (TC) and low-density lipoprotein-cholesterol (LDL-C) were modified for high-throughput analysis of DBS. Apolipoprotein B (ApoB) concentrations in DBS were measured using an immunoassay with modifications from published studies. All three assays were validated according to the College of American Pathologists guidelines for clinical laboratories. The performance of TC, LDL-C, and ApoB assays was assessed by precision, recovery, limit of quantification (LOQ) and linearity. Precision studies yielded coefficients of variation (CV) of less than 15%, with recovery greater than 75% for all three assays. The determined LOQ and linearity were comparable to serum-based assays. In a direct comparison between serum and DBS concentrations, positive correlations were demonstrated for TC, LDL-C, and ApoB. Additionally, the initial evaluation of the three biomarker concentrations within the unaffected population was similar to values obtained in previous published studies. This study reports on methods for quantification of TC, LDL-C, and ApoB in DBS. Assay validation results were within acceptable limits for newborn screening. This is an important first step toward the identification of newborns with HeFH.

Development of an Optimized Tetra-Amplification Refractory Mutation System PCR for Detection of 12 Pathogenic Familial Hypercholesterolemia Variants in the Asian Population

Early detection of genetic diseases such as familial hypercholesterolemia (FH), and the confirmation of related pathogenic variants, are crucial in reducing the risk for premature coronary artery disease. Currently, next-generation sequencing is used for detecting FH-related candidate genes but is expensive and time-consuming. There is a lack of kits suitable for the detection of the common FH-related variants in the Asia-Pacific region. Thus, this study addressed that need with the development of an optimized tetra-amplification mutation system (T-ARMS) PCR-based assay for the detection of 12 pathogenic variants of FH in the Asian population. The two important parameters for T-ARMS PCR assay performance-annealing temperature and the ratio of outer/inner primer concentrations-were optimized in this study. The optimal annealing temperature of all 12 T-ARMS PCR reactions was 64.6°C. The ideal ratios of outer/inner primer concentrations with each pathogenic variant were: A1, 1:2; A2, 1:4; L1, 1:10; L2, 1:1; L3, 1:2; L4, 1:8; L5, 1:1; L6, 1:2; L7, 1:8; L8, 1:8; L9, 1:2; and L10, 1:8. The lowest limit of detection using DNA extracted from patients was 0.1 ng. The present article highlights the beneficial findings on T-ARMS PCR as part of the development of a PCR-based detection kit for use in detecting FH in economically developing countries in Asia with a greater prevalence of FH.

Role of an automated screening tool for familial hypercholesterolemia in patients with premature coronary artery disease

Background and aims

To validate an automated screening tool for patients with premature coronary artery disease (CAD) and high total cholesterol or LDL-C levels and assess if it would provide clinicians with additional support in identifying patients with Familial Hypercholesterolemia (FH).

Methods

An IT-based automated screening tool based on coronary angiography data recorded in the KARDIO registry and laboratory values was validated among patients undergone coronary angiography in the Heart Hospital at Tampere University Hospital between 2007 and 2017 fulfilling the criteria of premature CAD (men <55 years and women <60 years) and history of high total cholesterol (>8 mmol/l) or LDL-cholesterol (>5 mmol/l) levels. Electronic health records were retrospectively analyzed to determine if these patients had been diagnosed with FH based on clinical features and whether genetic testing had been conducted.

Results

The automated screening tool identified 0.7% (211/28295) of all patients undergone coronary angiography and revealed history of high cholesterol in 8% (211/2678) of patients with premature CAD during the study period. Fifty-one percent (107/211) of these patients fulfilled the clinical criteria for probable/definite FH based on the Dutch Lipid Clinic Network (DLCN) criteria.None of the patients had been diagnosed with FH based on clinical criteria before or after diagnosis of CAD. Thirteen percent of patients (n = 14) with probable/definite FH had been tested for genetic mutations of FH before or after CAD, five (36%) of them having a pathogenic FH variant. Two patients were referred to cascade screening.

Conclusions

FH was underdiagnosed among the population studied. An automated screening tool in cardiac care could provide additional support for clinicians in diagnosing patients potentially having FH.

LDL cholesterol target achievement in heterozygous familial hypercholesterolemia patients according to 2019 ESC/EAS lipid guidelines: Implications for newer lipid-lowering treatments

BACKGROUND

The 2019 European guidelines (ESC/EAS) for the treatment of dyslipidaemias recommend more aggressive targets for low-density lipoprotein cholesterol (LDL-C) in patients with familial hypercholesterolemia (FH). Current lipid-lowering treatment is often inadequate to achieve these targets.

METHODS

Data from the HELLAS-FH registry were analysed to assess achievement of LDL-C targets in adults with FH based on the 2019 ESC/EAS guidelines. In patients who had not achieved LDL-C target, the maximally reduced LDL-C value was calculated after theoretical switch to rosuvastatin/ezetimibe 40/10 mg/day. The percentage of patients who remained candidates for proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) was then calculated.

RESULTS

Patients (n = 1694, mean age 50.8 ± 14.7 years) had LDL-C levels 242 ± 71 mg/dL (6.3 ± 1.8 mmol/L) at diagnosis. Most treated patients were receiving statins (97.5%) and about half were on additional ezetimibe (47.5%). Based on the 2019 ESC/EAS guidelines the percentage of patients achieving LDL-C goals was only 2.7%. Following theoretical up titration to rosuvastatin/ezetimibe 40/10 mg, LDL-C target achievement rate would increase to 5.9%. In this scenario, most patients (55.9%) would be eligible for PCSK9i treatment. Following theoretical administration of a PCSK9i, LDL-C target achievement rate would rise to 57.6%. However, 42.4% of patients would still be eligible for further LDL-C lowering treatment.

CONCLUSIONS

Most FH patients do not reach new LDL-C targets even if on maximum intensity statin/ezetimibe treatment. In this case, more than half of FH patients are candidates for PCSK9i therapy and a considerable proportion may still require additional LDL-C lowering.

High Cholesterol Diet Exacerbates Blood-Brain Barrier Disruption in LDLr-/- Mice: Impact on Cognitive Function

Background:

Evidence has revealed an association between familial hypercholesterolemia and cognitive impairment. In this regard, a connection between cognitive deficits and hippocampal blood-brain barrier (BBB) breakdown was found in low-density lipoprotein receptor knockout mice (LDLr–/–), a mouse model of familial hypercholesterolemia.

Objective:

Herein we investigated the impact of a hypercholesterolemic diet on cognition and BBB function in C57BL/6 wild-type and LDLr–/–mice.

Methods:

Animals were fed with normal or high cholesterol diets for 30 days. Thus, wild-type and LDLr–/–mice were submitted to memory paradigms. Additionally, BBB integrity was evaluated in the mice’s prefrontal cortices and hippocampi.

Results:

A tenfold elevation in plasma cholesterol levels of LDLr–/–mice was observed after a hypercholesterolemic diet, while in wild-type mice, the hypercholesterolemic diet exposure increased plasma cholesterol levels only moderately and did not induce cognitive impairment. LDLr–/–mice presented memory impairment regardless of the diet. We observed BBB disruption as an increased permeability to sodium fluorescein in the prefrontal cortices and hippocampi and a decrease on hippocampal claudin-5 and occludin mRNA levels in both wild-type and LDLr–/–mice treated with a hypercholesterolemic diet. The LDLr–/–mice fed with a regular diet already presented BBB dysfunction. The BBB-increased leakage in the hippocampi of LDLr–/–mice was related to high microvessel content and intense astrogliosis, which did not occur in the control mice.

Conclusion:

Therefore, LDLr–/–mice seem to be more susceptible to cognitive impairments and BBB damage induced by exposure to a high cholesterol diet. Finally, BBB disruption appears to be a relevant event in hypercholesterolemia-induced brain alterations.

A Western-style diet interacts with genetic variants of the LDL receptor to hyper-LDL cholesterolemia in Korean adults

OBJECTIVE

To evaluate the association of genetic risk scores (GRS) of LDLR, APOB and proprotein convertase subtilisin-kexin type 9 (PCSK9) SNP and plasma LDL concentrations and to identify lifestyle interactions with the GRS in Korean middle-aged adults.

DESIGN

Korean genome and epidemiology study (KoGES) was conducted to determine genetic variants and lifestyle factors, including nutrient intakes, in a retrospective hospital-based city cohort conducted by the Korean Center for Disease and Control during 2004-2013.

SETTINGS

Hospitals in Korea.

PARTICIPANTS

Adults aged 40-77 years (n 28 445) without serious diseases.

RESULTS

Subjects with the major alleles (risk allele) of LDLR rs1433099 and rs11557092, APOB rs13306194 and PCSK9 rs11583723 had higher plasma LDL concentration by 1·20-folds than those with the minor alleles. Subjects with High-GRS (major alleles) of the four SNP had higher adjusted OR for plasma total and LDL-cholesterol and TAG concentrations by 1·24-, 1·203- and 1·167-folds, respectively, but not HDL-cholesterol, than those with Low-GRS. Western-style flour-rich dietary patterns, but not balanced Korean-style and rice-based dietary patterns, had interactions with GRS to increase plasma LDL concentrations. Daily energy intake also interacted with GRS. In the high intake of Western-style flour-rich dietary patterns, carriers with High-GRS had much higher plasma LDL concentrations than the Low-GRS. With high energy intake, carriers with High-GRS had much higher plasma LDL concentrations than those with Low-GRS.

CONCLUSIONS

Adults with major alleles of four SNP are recommended to have low-energy intakes with a balanced Korean diet need to avoid high-energy intakes especially with Western-style flour-rich diet patterns.

Diagnosis and management of secondary causes of steatohepatitis

The term non-alcoholic fatty liver disease (NAFLD) was originally coined to describe hepatic fat deposition as part of the metabolic syndrome. However, a variety of rare hereditary liver and metabolic diseases, intestinal diseases, endocrine disorders and drugs may underlie, mimic, or aggravate NAFLD. In contrast to primary NAFLD, therapeutic interventions are available for many secondary causes of NAFLD. Accordingly, secondary causes of fatty liver disease should be considered during the diagnostic workup of patients with fatty liver disease, and treatment of the underlying disease should be started to halt disease progression. Common genetic variants in several genes involved in lipid handling and metabolism modulate the risk of progression from steatosis to fibrosis, cirrhosis and hepatocellular carcinoma development in NAFLD, alcohol-related liver disease and viral hepatitis. Hence, we speculate that genotyping of common risk variants for liver disease progression may be equally useful to gauge the likelihood of developing advanced liver disease in patients with secondary fatty liver disease.

The Effect of Statins in Children and Adolescents With Familial Hypercholesterolemia: A Systematic Review

INTRODUCTION

Familial hypercholesterolemia (FH) is a genetic disorder that causes elevated low-density lipoprotein-cholesterol (LDL-C) levels. If undiagnosed and untreated in childhood, affected individuals can suffer premature health complications. Statins reduce the risks of complications for adults, but less is known about children. This systematic review examined the effectiveness of statin therapy for lowering LDL-C levels in children with FH.

METHOD

Medline Ovid, Embase, CINAHL, and Allied Health Literature Plus were searched for studies that examined the effectiveness of stains in children ages 1-18 years with heterozygous FH.

RESULTS

Of the 706 articles identified, 10 were included in the review. Statin therapy significantly reduced LDL-C levels in pediatric patients with FH. Statins were safe and well-tolerated with minimal adverse effects.

DISCUSSION

Pediatric providers should be familiar with diagnosis, treatment, and management of FH to successfully lower LDL-C levels and avoid potential long-term health effects. Evidence suggests statins are safe and effective in children with FH.

Familial hypercholesterolemia in Mexico: Initial insights from the national registry

BACKGROUND

Familial hypercholesterolemia (FH) remains underdiagnosed and undertreated.

OBJECTIVE

Report the results of the first years (2017-2019) of the Mexican FH registry.

METHODS

There are 60 investigators, representing 28 federal states, participating in the registry. The variables included are in accordance with the European Atherosclerosis Society (EAS) FH recommendations.

RESULTS

To date, 709 patients have been registered, only 336 patients with complete data fields are presented. The mean age is 50 (36-62) years and the average time since diagnosis is 4 (IQR: 2-16) years. Genetic testing is recorded in 26.9%. Tendon xanthomas are present in 43.2%. The prevalence of type 2 diabetes is 11.3% and that of premature CAD is 9.8%. Index cases, male gender, hypertension and smoking were associated with premature CAD. The median lipoprotein (a) level is 30.5 (IQR 10.8-80.7) mg/dl. Statins and co-administration with ezetimibe were recorded in 88.1% and 35.7% respectively. A combined treatment target (50% reduction in LDL-C and an LDL-C <100 mg/dl) was achieved by 13.7%. Associated factors were index case (OR 3.6, 95%CI 1.69-8.73, P = .002), combination therapy (OR 2.4, 95%CI 1.23-4.90, P = .011), type 2 diabetes (OR 2.8, 95%CI 1.03-7.59, P = .036) and age (OR 1.023, 95%CI 1.01-1.05, P = .033).

CONCLUSION

The results confirm late diagnosis, a lower than expected prevalence and risk of ASCVD, a higher than expected prevalence of type 2 diabetes and undertreatment, with relatively few patients reaching goals. Recommendations include, the use of combination lipid lowering therapy, control of comorbid conditions and more frequent genetic testing in the future.

Tackling cardiometabolic risk in the Asia Pacific region

With the global spread of abdominal obesity, cardiovascular disease continues to spread to all countries of the world. Given the large population, the challenges presented by cardiometabolic risk in the Asia Pacific region are considerable. In addition to the clinical consequences of cardiovascular disease, in terms of its morbidity and mortality, the diversity of the Asia Pacific region brings heterogeneity in approaches to prevention, diagnosis and treatment of cardiometabolic risk. In this manuscript, we will review the current state of knowledge of cardiometabolic risk in Asia Pacific and highlight the needs moving forward to tackle this public health challenge.

Prevalence of Familial Hypercholesterolemia Among the General Population and Patients With Atherosclerotic Cardiovascular Disease

Background:

Contemporary studies suggest that familial hypercholesterolemia (FH) is more frequent than previously reported and increasingly recognized as affecting individuals of all ethnicities and across many regions of the world. Precise estimation of its global prevalence and prevalence across World Health Organization regions is needed to inform policies aiming at early detection and atherosclerotic cardiovascular disease (ASCVD) prevention. The present study aims to provide a comprehensive assessment and more reliable estimation of the prevalence of FH than hitherto possible in the general population (GP) and among patients with ASCVD.

Methods:

We performed a systematic review and meta-analysis including studies reporting on the prevalence of heterozygous FH in the GP or among those with ASCVD. Studies reporting gene founder effects and focused on homozygous FH were excluded. The search was conducted through Medline, Embase, Cochrane, and Global Health, without time or language restrictions. A random-effects model was applied to estimate the overall pooled prevalence of FH in the general and ASCVD populations separately and by World Health Organization regions.

Results:

From 3225 articles, 42 studies from the GP and 20 from populations with ASCVD were eligible, reporting on 7 297 363 individuals/24 636 cases of FH and 48 158 patients/2827 cases of FH, respectively. More than 60% of the studies were from Europe. Use of the Dutch Lipid Clinic Network criteria was the commonest diagnostic method. Within the GP, the overall pooled prevalence of FH was 1:311 (95% CI, 1:250–1:397; similar between children [1:364] and adults [1:303], P =0.60; across World Health Organization regions where data were available, P =0.29; and between population-based and electronic health records–based studies, P =0.82). Studies with ≤10 000 participants reported a higher prevalence (1:200–289) compared with larger cohorts (1:365–407; P <0.001). The pooled prevalence among those with ASCVD was 18-fold higher than in the GP (1:17 [95% CI, 1:12–1:24]), driven mainly by coronary artery disease (1:16; [95% CI, 1:12–1:23]). Between-study heterogeneity was large ( I 2 >95%). Tests assessing bias were nonsignificant ( P >0.3).

Conclusions:

With an overall prevalence of 1:311, FH is among the commonest genetic disorders in the GP, similarly present across different regions of the world, and is more frequent among those with ASCVD. The present results support the advocacy for the institution of public health policies, including screening programs, to identify FH early and to prevent its global burden.

STATINS TREATMENT AND ORO-DENTAL ASPECTS IN A CASE OF HEREDITARY HYPERCHOLESTEROLEMIA IN A CHILD UNDER 6 YEARS

Familial hypercholesterolemia (FH) is a genetic disease with autosomal dominant transmission, characterised by high blood cholesterol levels. The evolution of this disease leads to primary atherosclerosis and cardiovascular disease. Patients with HF develop atherosclerosis by the age of 20 and usually do not survive past the age of 30. We present the case and oro-dental aspects of a preschooler that was diagnosed at the age of 4 with FH, compound heterozygote (mutation/genotype1 LDLR: C20IX, exon 4; mutation/genotype2 LDLR: G571E, exon 12) and the experience of our clinic in the management of this patient that received off-label treatment with statins. When diagnosed, his cholesterol level was 932 mg/dL and his LDL-cholesterol level was 792 mg/dL. Treatment with rosuvastatin and ezetimibe was prescribed. Both substances (rosuvastatin and ezetimibe) are not approved for children under the age of 6 in Europe. Taking into considerations the diagnosis and prognosis for unfavorable evolution, treatment with statins was started at the age of 5 years.

Ochronotic pigmentation is caused by homogentisic acid and is the key event in alkaptonuria leading to the destructive consequences of the disease-A review

Ochronosis is the process in alkaptonuria (AKU) that causes all the debilitating morbidity. The process involves selective deposition of homogentisic acid (HGA)-derived pigment in tissues altering the properties of these tissues, leading to their failure. Some tissues like cartilage are more easily affected by ochronosis while others such as the liver and brain are unaffected for reasons that are still not understood. In vitro and mouse models of ochronosis have confirmed the dose relationships between HGA and ochronosis and also their modulation by p-hydroxyphenylpyruvate dioxygenase inhibition. Ochronosis cannot be fully reversed and is a key factor in influencing treatment decisions. Earlier detection of ochronosis preferably by noninvasive means is desirable. A cause-effect relationship between HGA and ochronosis is discussed. The similarity in AKU and familial hypercholesterolaemia is explored and lessons learnt. More research is needed to more fully understand the crucial nature of ochronosis.

Overview of the current status of familial hypercholesterolaemia care in over 60 countries - The EAS Familial Hypercholesterolaemia Studies Collaboration (FHSC)

BACKGROUND AND AIMS

Management of familial hypercholesterolaemia (FH) may vary across different settings due to factors related to population characteristics, practice, resources and/or policies. We conducted a survey among the worldwide network of EAS FHSC Lead Investigators to provide an overview of FH status in different countries.

METHODS

Lead Investigators from countries formally involved in the EAS FHSC by mid-May 2018 were invited to provide a brief report on FH status in their countries, including available information, programmes, initiatives, and management.

RESULTS

63 countries provided reports. Data on FH prevalence are lacking in most countries. Where available, data tend to align with recent estimates, suggesting a higher frequency than that traditionally considered. Low rates of FH detection are reported across all regions. National registries and education programmes to improve FH awareness/knowledge are a recognised priority, but funding is often lacking. In most countries, diagnosis primarily relies on the Dutch Lipid Clinics Network criteria. Although available in many countries, genetic testing is not widely implemented (frequent cost issues). There are only a few national official government programmes for FH. Under-treatment is an issue. FH therapy is not universally reimbursed. PCSK9-inhibitors are available in ∼2/3 countries. Lipoprotein-apheresis is offered in ∼60% countries, although access is limited.

CONCLUSIONS

FH is a recognised public health concern. Management varies widely across countries, with overall suboptimal identification and under-treatment. Efforts and initiatives to improve FH knowledge and management are underway, including development of national registries, but support, particularly from health authorities, and better funding are greatly needed.

Guest Editorial: Reducing Risk in Familial Hypercholesterolaemia and Severe Dyslipidaemia: Novel Drugs Targeting PCSK9

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