Diagnosing heterozygous familial hypercholesterolemia using new practical criteria validated by molecular genetics

Lipids, lipoproteins and prevalence of familial hypercholesterolemia in the Faroe Islands - Results from a nationwide laboratory database

BACKGROUND AND AIMS

Familial hypercholesterolemia (FH) is one of the most common hereditary disorders. The population of the Faroe Islands was established by few founders, and genetic drift may have influenced lipid levels. The aim of this study was to describe the lipid distribution by providing age and sex-specific lipid values and to investigate the prevalence of FH in the Faroe Islands.

METHODS

We used an electronic nationwide laboratory database that included lipid measurements obtained in the Faroe Islands between January 2006 and September 2020. Percentiles of lipid levels were calculated using quantile regression. The prevalence of FH was estimated according to the Make Early Diagnosis Prevent Early Death (MEDPED) diagnostic criteria and according to the LDL-C cut-off levels included in the Dutch Lipid Clinic Network (DLCN) criteria using generalized linear models with robust variance.

RESULTS

According to the MEDPED age-specific cut-offs for LDL-C, a total of 216 subjects met the criteria for definite FH among 30,711 individuals corresponding to a prevalence of 0.70% (1:142). According to the LDL-C cut-offs included in the DLCN criteria, a total of 3,823 (1:8) subjects could be classified as having possible FH, and 10 (1:3,071) subjects could be classified as probable FH corresponding to a prevalence of 12.4% and 0.03%, respectively. Also, we found significant differences in lipid levels according to sex and age groups.

CONCLUSION

The Faroe Islands might represent a founder population with a prevalence of possible FH as high as 1 in 8. Further investigation of genetic and clinical characteristics of FH in the Faroe Islands is needed.

Population-based screening in children for early diagnosis and treatment of familial hypercholesterolemia: design of the VRONI study

Familial hypercholesterolemia (FH) is the most frequent monogenic disorder (prevalence 1:250) in the general population. Early diagnosis during childhood enables pre-emptive treatment, thus reducing the risk of severe atherosclerotic manifestations later in life. Nonetheless, FH screening programs are scarce. VRONI offers all children aged 5-14 years in Bavaria a FH screening in the context of regular pediatric visits. LDL-cholesterol (LDL-C) is measured centrally, followed by genetic analysis for FH if exceeding the age-specific 95th percentile (130 mg/dl, 3.34 mmol/l). Children with FH pathogenic variants are treated by specialized pediatricians and offered a FH-focused training course by a qualified training center. Reverse cascade screening is recommended for all first-degree relatives. VRONI aims to prove the feasibility of a population-based FH screening in children and to lay the foundation for a nationwide screening program.

Genetic Lipid Disorders Associated with Atherosclerotic Cardiovascular Disease: Molecular Basis to Clinical Diagnosis and Epidemiologic Burden

Genetic lipid disorders, ranging from common dyslipidemias such as familial hypercholesterolemia, lipoprotein (a), and familial combined hyperlipidemia to rare disorders including familial chylomicronemia syndrome and inherited hypoalphalipoproteinemias (ie, Tangier and fish eye diseases), affect millions of individuals in the United States and tens of millions around the world and are often undiagnosed in the general population. Clinicians should take into consideration the potential of inherited lipid disorders or syndromes when severe derangements in lipid parameters are observed. Patients' combined genotype and phenotype should be evaluated in conjunction with a host of environmental factors impacting their risk of atherosclerotic cardiovascular disease.

A Bibliometric Analysis of Familial Hypercholesterolemia From 2011 to 2021

Familial Hypercholesterolemia (FH), an autosomal dominant genetic disease, is increasingly emerging as a global threat. To learn more about the development of FH, 1 617 papers about FH and related research were retrieved in the Web of Science Core Collection from 2011 to 2021. Then, these publications were scientometrically analyzed based on CiteSpace and VOSviewer in terms of spatiotemporal distribution, author distribution, subject categories, topic distribution, and references. The results showed that research on FH is at a stable stage. More FH research has been conducted in developed countries, implying the necessity for strengthening international cooperation and exchanges. We have obtained scholars, institutions, relevant journals, and representative literatures that play an important role in FH. The research direction of FH is on the mechanisms of FH and its complications, diagnosis, statin therapy, and new lipid-lowering drug therapy. Care is the research frontier in FH, and it is in an explosive period.

Population-based screening in children for early diagnosis and treatment of familial hypercholesterolemia: design of the VRONI study

Background

Heterozygous familial hypercholesterolemia (FH) represents the most frequent monogenic disorder with an estimated prevalence of 1:250 in the general population. Diagnosis during childhood enables early initiation of preventive measures, reducing the risk of severe consecutive atherosclerotic manifestations. Nevertheless, population-based screening programs for FH are scarce.

Methods

In the VRONI study, children aged 5–14 years in Bavaria are invited to participate in an FH screening program during regular pediatric visits. The screening is based on low-density lipoprotein cholesterol measurements from capillary blood. If exceeding 130 mg/dl (3.34 mmol/l), i.e. the expected 95th percentile in this age group, subsequent molecular genetic analysis for FH is performed. Children with FH pathogenic variants enter a registry and are treated by specialized pediatricians. Furthermore, qualified training centers offer FH-focused training courses to affected families. For first-degree relatives, reverse cascade screening is recommended to identify and treat affected family members.

Results

Implementation of VRONI required intensive prearrangements for addressing ethical, educational, data safety, legal and organizational aspects, which will be outlined in this article. Recruitment started in early 2021, within the first months, more than 380 pediatricians screened over 5200 children. Approximately 50 000 children are expected to be enrolled in the VRONI study until 2024.

Conclusions

VRONI aims to test the feasibility of a population-based screening for FH in children in Bavaria, intending to set the stage for a nationwide FH screening infrastructure. Furthermore, we aim to validate genetic variants of unclear significance, detect novel causative mutations and contribute to polygenic risk indices (DRKS00022140; August 2020).

Lipoprotein(a) as Part of the Diagnosis of Clinical Familial Hypercholesterolemia

PURPOSE OF REVIEW

Individuals with familial hypercholesterolemia have very high risk of cardiovascular disease due to lifelong elevations in LDL cholesterol. Elevated lipoprotein(a) is a risk factor for cardiovascular diseases such as myocardial infarction and aortic valve stenosis. It has been proposed to include elevated lipoprotein(a) in the diagnosis of clinical familial hypercholesterolemia.

RECENT FINDINGS

Lipoprotein(a) is co-measured in LDL cholesterol, and up to one-quarter of all diagnoses of clinical familial hypercholesterolemia are due to high levels of lipoprotein(a). Further, individuals with both familial hypercholesterolemia and elevated lipoprotein(a) have an extremely high risk of myocardial infarction. We discuss the background for familial hypercholesterolemia and elevated lipoprotein(a) as risk factors for cardiovascular disease and the consequences of the fact that LDL cholesterol measurements/calculations include the cholesterol present in lipoprotein(a). Finally, we discuss the potential of including lipoprotein(a) as part of the diagnosis of familial hypercholesterolemia and in consequence possible treatments.

A novel low-density lipoprotein receptor variant in a Ukrainian patient: a case report and overview of the disease-causing low-density lipoprotein receptor variants associated to familial hypercholesterolemia

BACKGROUND

Familial hypercholesterolemia (FH) is characterized by high low-density lipoprotein-cholesterol levels and it is primarily caused by pathogenic/likely pathogenic variants (P/LPVs) in LDLR, APOB or PCSK9 genes. Next generation sequencing (NGS) technology allows the evaluation of more genes simultaneously, rising the diagnostic throughput of genomics laboratories.

MATERIALS AND METHODS

We report a Ukrainian 37-year-old woman hypercholesterolemic since 2010. Despite a suggestive family history, FH was suspected only when the patient referred to the Endocrine and Metabolic Diseases Center of the Fondazione Policlinico Universitario A. Gemelli IRCCS in Rome. After specialist advice, genetic testing was offered to the patient at our Molecular and Genomic Diagnostics Unit.

RESULTS

A targeted NGS-based pipeline highlighted a novel out-of-frame deletion in the LDLR gene. This variant has a clear deleterious effect on the LDLR protein and it can be classified as PV.

CONCLUSIONS

The ideal model of care for FH is an evidence-based system aimed to provide the highest-quality health services to all FH patients. In fact, this study reports that the integrated care pathway adopted in our hospital for FH patients led successfully to the discovery of a novel LDLR PV in an Ukrainian patient. The finding of this LDLR variant allowed the clinical FH diagnosis in this patient and in her family, expanding the knowledge of FH-related genetic variants in the Ukrainian population.

Case Studies in Pediatric Lipid Disorders and Their Management

CONTEXT

Identification of modifiable risk factors, including genetic and acquired disorders of lipid and lipoprotein metabolism, is increasingly recognized as an opportunity to prevent premature cardiovascular disease (CVD) in at-risk youth. Pediatric endocrinologists are at the forefront of this emerging public health concern and can be instrumental in beginning early interventions to prevent premature CVD-related events during adulthood.

AIM

In this article, we use informative case presentations to provide practical approaches to the management of pediatric dyslipidemia.

CASES

We present 3 scenarios that are commonly encountered in clinical practice: isolated elevation of low-density lipoprotein cholesterol (LDL-C), combined dyslipidemia, and severe hypertriglyceridemia. Treatment with statin is indicated when the LDL-C is ≥190 mg/dL (4.9 mmol/L) in children ≥10 years of age. For LDL-C levels between 130 and 189 mg/dL (3.4-4.89 mmol/L) despite dietary and lifestyle changes, the presence of additional risk factors and comorbid conditions would favor statin therapy. In the case of combined dyslipidemia, the primary treatment target is LDL-C ≤130 mg/dL (3.4 mmol/L) and the secondary target non-high-density lipoprotein cholesterol <145 mg/dL (3.7 mmol/L). If the triglyceride is ≥400 mg/dL (4.5 mmol/L), prescription omega-3 fatty acids and fibrates are considered. In the case of triglyceride >1000 mg/dL (11.3 mmol/L), dietary fat restriction remains the cornerstone of therapy, even though the landscape of medications is changing.

CONCLUSION

Gene variants, acquired conditions, or both are responsible for dyslipidemia during childhood. Extreme elevations of triglycerides can lead to pancreatitis. Early identification and management of dyslipidemia and cardiovascular risk factors is extremely important.

The Clinical Genome Resource (ClinGen) Familial Hypercholesterolemia Variant Curation Expert Panel consensus guidelines for LDLR variant classification

PURPOSE

In 2015, the American College of Medical Genetics and Genomics (ACMG) and the Association for Molecular Pathology (AMP) published consensus standardized guidelines for sequence-level variant classification in Mendelian disorders. To increase accuracy and consistency, the Clinical Genome Resource Familial Hypercholesterolemia (FH) Variant Curation Expert Panel was tasked with optimizing the existing ACMG/AMP framework for disease-specific classification in FH. In this study, we provide consensus recommendations for the most common FH-associated gene, LDLR, where >2300 unique FH-associated variants have been identified.

METHODS

The multidisciplinary FH Variant Curation Expert Panel met in person and through frequent emails and conference calls to develop LDLR-specific modifications of ACMG/AMP guidelines. Through iteration, pilot testing, debate, and commentary, consensus among experts was reached.

RESULTS

The consensus LDLR variant modifications to existing ACMG/AMP guidelines include (1) alteration of population frequency thresholds, (2) delineation of loss-of-function variant types, (3) functional study criteria specifications, (4) cosegregation criteria specifications, and (5) specific use and thresholds for in silico prediction tools, among others.

CONCLUSION

Establishment of these guidelines as the new standard in the clinical laboratory setting will result in a more evidence-based, harmonized method for LDLR variant classification worldwide, thereby improving the care of patients with FH.

Effectiveness of cascade testing strategies in relatives for familial hypercholesterolemia: A systematic review and meta-analysis

BACKGROUND AND AIMS

Cascade testing in relatives of index cases is the most cost-effective approach to identifying people with familial hypercholesterolemia (FH); however, it is currently unclear which strategy to contact relatives would be the most effective. A systematic review was performed to quantify the effectiveness of different strategies in cascade testing of FH.

METHODS

Comprehensive searches of three electronic databases and grey literature sources were done (from inception to May 2020). Screening, data extraction and assessments of methodological quality were made independently by two reviewers. Meta-analyses of proportions were performed using random effects models. Effect measures are reported as percentages with 95% confidence intervals.

RESULTS

24 non-comparative studies were included, of which 11 used a direct, 8 used an indirect, and 5 used a combination of both direct and indirect cascade strategies. The median number of new relatives with FH per known index case was approximately 1. The combination strategy resulted in the largest yields of relatives tested for FH out of those contacted (40%, 95% CI 37%-42%, 1 study) and relatives responding to testing out of those contacted (54%, 1 study); however, the direct strategy had the largest yield of index cases participating in cascade testing out of those with FH confirmed (94%, 8 studies) compared to other strategies (p ≤ 0.01 for all comparisons).

CONCLUSIONS

Evidence is limited; however, a combination strategy, which allows the index case to decide on method of contacting relatives, appears to lead to better yields compared to using the direct or indirect strategy.

FH ALERT: efficacy of a novel approach to identify patients with familial hypercholesterolemia

Diagnosis rates of familial hypercholesterolemia (FH) remain low. We implemented FH ALERT to assess whether alerting physicians for the possibility of FH impacted additional diagnostic activity. The study was conducted from SYNLAB laboratory Weiden (Bavaria). Beyond common reporting of LDL-C or TC, 1411 physicians covering approximately a population of 1.5 million people were eligible to receive an alert letter (AL) including information on FH, if laboratory results exceeded thresholds as follows: adults LDL-C ≥ 190–250 mg/dl (to convert into mmol/l multiply with 0.0259), TC ≥ 250 to ≤ 310 mg/dl (probable suspicion); LDL-C > 250 mg/dl and TC > 310 mg/dl (strong suspicion). Persons below 18 years were alerted for LDL-C  140 mg/dl and TC ≥ 200 mg/dl (strong suspicion). Patients above 60 years were excluded. Our readouts were characteristics of involved physicians, rate of ALs issued, acceptance, and subsequent diagnostic activity. Physicians were mainly general practitioners in ambulatory care. 75% of the ordered tests were for TC, 25% for LDL-C. We issued 3512 ALs (~ 5% of tests) triggered by 2846 patients. 86% of eligible physicians stayed with the initiative, 32.7% were alerted, and 70% were positive upon call-center survey. We registered 101 new visitors of www.fhscore.eu and sent out 93 kits for genetics. Thereof, 26 were returned and 5 patients were positive for FH. Physicians were in general open to our approach. Although genetic testing was taken up with caution, this 3-months pilot examination resulted in a greater rate of patients with FH diagnosed than previous screening projects. Further education on FH in primary care is required to improve FH detection in the community.

Strategies for screening for familial hypercholesterolaemia in primary care and other community settings

BACKGROUND

Familial hypercholesterolaemia is a common inherited condition that is associated with premature cardiovascular disease. The increased cardiovascular morbidity and mortality, resulting from high levels of cholesterol since birth, can be prevented by starting lipid-lowering therapy. However, the majority of patients in the UK and worldwide remain undiagnosed. Established diagnostic criteria in current clinical practice are the Simon-Broome and Dutch Lipid Clinical network criteria and patients are classified as having probable, possible or definite familial hypercholesterolaemia.

OBJECTIVES

To assess the effectiveness of healthcare interventions strategies to systematically improve identification of familial hypercholesterolaemia in primary care and other community settings compared to usual care (incidental approaches to identify familial hypercholesterolaemia in primary care and other community settings).

SEARCH METHODS

We searched the Cochrane Inborn Errors of Metabolism Trials Register. Date of last search: 13 September 2021. We also searched databases (Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE, PubMed, Embase, CINAHL, Web of Science, and SCOPUS) as well as handsearching relevant conference proceedings, reference lists of included articles, and the grey literature. Date of last searches: 05 March 2020.  SELECTION CRITERIA: As per the Effective Practice and Organisation of Care (EPOC) Group guidelines, we planned to include randomised controlled trials (RCTs), cluster-RCTs and non-randomised studies of interventions (NRSI). Eligible NRSI were non-randomised controlled trials, prospective cohort studies, controlled before-and-after studies, and interrupted-time-series studies. We planned to selected studies with healthcare interventions strategies that aimed to systematically identify people with possible or definite clinical familial hypercholesterolaemia, in primary care and other community settings. These strategies would be compared with usual care or no intervention. We considered participants of any age from the general population who access primary care and other community settings.

DATA COLLECTION AND ANALYSIS

Two authors planned to independently select studies according to the inclusion criteria, to extract data and assess for risk of bias and the certainty of the evidence (according to the GRADE criteria). We contacted corresponding study authors in order to obtain further information for all the studies considered in the review.

MAIN RESULTS

No eligible RCTs or NRSIs were identified for inclusion, however, we excluded 28 studies.

AUTHORS' CONCLUSIONS

Currently, there are no RCTs or controlled NRSI evidence to determine the most appropriate healthcare strategy to systematically identify possible or definite clinical familial hypercholesterolaemia in primary care or other community settings. Uncontrolled before-and-after studies were identified, but were not eligible for inclusion. Further studies assessing healthcare strategies of systematic identification of familial hypercholesterolaemia need to be conducted with diagnosis confirmed by genetic testing or validated through clinical phenotype (or both).

Awareness, diagnosis and treatment of heterozygous familial hypercholesterolemia (HeFH) - Results of a US national survey

BACKGROUND

HeFH is a common inherited disorder that leads to markedly elevated LDL-cholesterol from birth and premature cardiovascular disease. HeFH is frequently underdiagnosed and undertreated.

OBJECTIVE

To compare how well primary care physicians and cardiologists recognize and treat HeFH.

METHODS

The National Lipid Association surveyed 500 primary care physicians and 500 cardiologists in the US who have patients with baseline LDL-cholesterol ≥ 190 mg/dL. The survey was conducted between August 29 and September 30, 2019.

RESULTS

For a hypothetical case of HeFH, 57% of cardiologists versus 43% of primary care physicians made the correct diagnosis (P<0.001). Among respondents, 21% of cardiologists versus 29% of primary care physicians have never made a diagnosis of HeFH in a patient with an LDL-cholesterol ≥ 190 mg/dL (P<0.004). Only 7% of cardiologists versus 5% of primary care physicians would refer to a lipid specialist (P=0.05). For additional LDL-cholesterol lowering after statins, 58% of cardiologists versus 48% of primary care physicians would prescribe a PCSK9 inhibitor (P=0.004); however, 30% of cardiologists versus 53% of primary care physicians have never prescribed a PSCK9 inhibitor in an HeFH patient (P<0.001).

CONCLUSION

Although cardiologists compared to primary care physicians are somewhat more likely to recognize and treat HeFH patients according to guidelines, both physician specialties do not adequately recognize or treat HeFH. There is a need for more education and training in recognizing and treating HeFH, greater access to lipid specialists, and fewer barriers for PCSK9 inhibitor use.

The Propagation of Racial Disparities in Cardiovascular Genomics Research

Genomics research has improved our understanding of the genetic basis for human traits and diseases. This progress is now being translated into clinical care as we move toward a future of precision medicine. Many hope that expanded use of genomic testing will improve disease screening, diagnosis, risk stratification, and treatment. In many respects, cardiovascular medicine is leading this charge. However, most cardiovascular genomics research has been conducted in populations of primarily European ancestry. This bias has critical downstream effects. Here, we review the current disparities in cardiovascular genomics research, and we outline how these disparities propagate forward through all phases of the translational pipeline. If not adequately addressed, biases in genomics research will further compound the existing health disparities that face underrepresented and marginalized populations.

Familial Hypercholesterolemia: Global Burden and Approaches

PURPOSE OF REVIEW

Familial hypercholesterolemia (FH) is the most common genetic metabolic disorder characterized by markedly elevated LDL-C levels from birth leading to atherosclerotic cardiovascular disease (ASCVD) and premature deaths. The purpose of this review is to share the current knowledge in the diagnosis, risk estimation, and management of patients with FH in the light of recent evidence and guideline recommendations.

RECENT FINDINGS

Recent registries underscored the prevalence of FH as 1/200-250 translating to an almost 1500 million subjects suffering from FH worldwide. However, only a minority of FH patients are identified early and effectively treated. In most cases, mutations in the LDL-receptor (LDLR) gene and to a lesser degree in the apolipoprotein B-100 (APOB), proprotein convertase subtilisin/kexin type 9 (PCSK9), and the LDL-receptor adaptor protein 1 (LDLRAP1) genes cause FH. Diagnostic scores such as Dutch Lipid Clinic Network criteria using clinical manifestations are helpful in identifying FH. Traditional risk factors and high lipoprotein(a) affect the course of the disease. Vascular ultrasound imaging and coronary calcium scoring are helpful for further risk estimation of these patients. Getting to LDL-C goals is possible with currently available treatments including statins, ezetimibe, and PCSK9 inhibitors, as well as lipoprotein apheresis, lomitapide, and mipomersen in more severe phenotypes. Additionally, novel agents bempedoic acid, inclisiran, and evinacumab expanded the treatment choices for some patients with FH. Early diagnosis and initiation of LDL-C lowering are still required to achieve the greatest reduction in ASCVD morbidity and mortality in patients with FH. FH is a common genetic disorder characterized by markedly elevated LDL-C levels from birth onward, resulting in significantly increased risk for ASCVD. Despite major advances in our understanding of the disease and effective therapies, FH is still underdiagnosed and undertreated. Early initiation of LDL-C lowering by increased awareness of FH among the healthcare professionals, patients, and the public is necessary to achieve meaningful reduction in ASCVD morbidity and mortality in these patients.

Prevention of Atherosclerotic Cardiovascular Disease in Children with Familial Hypercholesterolemia

PURPOSE OF REVIEW

Familial hypercholesterolemia (FH), a common inherited disorder of LDL-C metabolism that predisposes to premature cardiovascular disease, is underdiagnosed. Despite recommendations for screening all children and initiation of lipid-lowering medication beginning at 8-10 years of age, adherence to guidelines is low. Most individuals with FH are inadequately treated, especially women and children. The purpose of this review is to discuss current literature and recommendations for the diagnosis and treatment of heterozygous FH (HeFH) in the pediatric population.

RECENT FINDINGS

Twenty-year outcome data demonstrate lower rates of atherosclerotic cardiovascular disease (ASCVD) related events and death in individuals with FH who were treated with statins from childhood, compared to those who initiated statins in adulthood. While diagnosis rates of FH are slowly improving, most clinicians do not adhere to recommendations for cholesterol screening in youth. Identifying youth with FH offers the opportunity for early intervention to prevent ASCVD and identify affected relatives through reverse cascade screening.

The importance of cascade genetic screening for diagnosing autosomal dominant hypercholesterolemia: Results from twenty years of a national screening program in Norway

BACKGROUND

The most cost-effective strategy to diagnose patients with autosomal dominant hypercholesterolemia (ADH) is to perform cascade genetic screening.

OBJECTIVE

To present the cascade genetic screening program for ADH in Norway.

METHODS

A national cascade genetic screening program for ADH in Norway has been operating at Unit for Cardiac and Cardiovascular Genetics, Oslo University Hospital for twenty years. This program has been run by just one genetic counsellor. We now present the main findings of this cascade genetic screening program.

RESULTS

After genetic counselling, 8182 at-risk relatives have consented to genetic testing for the mutation that causes ADH in the family. Of these, 3076 (37.6%) relatives have tested positive. Among mutation-positive relatives 31.3% were on lipid-lowering therapy at the time of genetic testing. However, only 9.8% of these relatives had a value for low density lipoprotein (LDL) cholesterol below 2.5 mmol/l (97 mg/dl). At follow-up six months after genetic testing, reductions in the levels of total serum cholesterol and LDL cholesterol of 12% and 17%, respectively were observed. A total of 8811 ADH heterozygotes have been diagnosed in Norway. Thus, the number of patients diagnosed by this modest cascade genetic screening program constitutes 35% of all Norwegian ADH patients provided with a molecular genetic diagnosis.

CONCLUSION

Cascade genetic screening for ADH is very effective and should be organized at a national level. Even a modest cascade genetic screening program with small resources, can result in a large number of patients being identified.

Evinacumab for treatment of familial hypercholesterolemia

Introduction: Familial hypercholesterolemia (FH) is characterized by lifelong elevation of low-density lipoprotein cholesterol (LDL-C), early onset coronary atherosclerosis, and premature death. FH is underdiagnosed and undertreated, but requires aggressive LDL-C-lowering to prevent complications. Current treatment strategies such as lifestyle modification and numerous LDL-C-lowering medications are often insufficient to achieve lipid goals in FH.Areas covered: Angiopoietin-like 3 protein (ANGPTL3) is intricately involved in lipid metabolism. Loss-of-function mutations in ANGPTL3 are associated with panhypolipidemia and reduced coronary atherosclerosis. Evinacumab, a fully human monoclonal antibody, inhibits ANGPTL3 and reduces multiple lipoprotein fractions ~50%, including LDL-C. The use of evinacumab within the FH population is described as well as its regulatory journey to an approved therapeutic.Expert opinion: Evinacumab, with its capacity to lower multiple lipoprotein fractions, particularly LDL-C, independently of LDLR function has potential to revolutionize treatment for FH patients. Current FDA-approval is only for homozygous FH (HoFH), arguably the most impactful indication, but use in other lipid disorders is under investigation. The short-term tolerability of evinacumab is very good, with infrequent, mild, and transient adverse events; however, long-term safety data are needed. The high cost and requirement for intravenous administration may limit adoption of evinacumab, but dramatic LDL-C-lowering and need for new therapeutic options for HoFH will drive interest.

Clinical Diagnostic Criteria of Familial Hypercholesterolemia - A Comparison of the Japan Atherosclerosis Society and Dutch Lipid Clinic Network Criteria

BACKGROUND

This study is aimed to compare the efficacy of the 2017 Japan Atherosclerosis Society (JAS) familial hypercholesterolemia (FH) criteria, which focuses on only 3 essential clinical manifestations, with that of Dutch Lipid Clinic Network (DLCN) FH criteria, which adopts a scoring system of multiple elements.

METHODS AND RESULTS

A total of 680 Japanese dyslipidemic participants (51% men) were enrolled between 2006 and 2018, all of whom had full evaluations of low-density lipoprotein (LDL) cholesterol, Achilles tendon X-rays, family history records, and genetic analysis of FH-associated genes (LDLR,APOB, andPCSK9). Predictive values for the existence of FH mutations by both clinical criteria were evaluated. Overall, 173 FH patients were clinically diagnosed by using the 2017 JAS criteria and 100, 57, 156, and 367 subjects were also diagnosed as having definite, probable, possible, and unlikely FH by the DLCN FH criteria, respectively. The positive and negative likelihood ratio predicting the presence of FH mutations by using the 2017 JAS FH criteria were 19.8 and 0.143, respectively; whereas, using the DLCN criteria of definite, probable, and possible FH, the ratios were 29.2 and 0.489, 9.70 and 0.332, and 3.43 and 0.040, respectively.

CONCLUSIONS

Among Japanese patients, the JAS 2017 FH criteria is considered superior to diagnose FH mutation-positive patients and simultaneously rule out FH mutation-negative patients compared with the DLCN FH criteria.

Current Approach to the Diagnosis and Treatment of Heterozygote and Homozygous FH Children and Adolescents

Purpose of Review

To elucidate the current approach of care in pediatric patients with familial hypercholesterolemia (FH). We sought an answer to the question whether the advances and major changes in lipid management are relevant and apply to children and adolescents.

Recent Findings

Latest research findings clearly demonstrate that lowering cholesterol levels at a young age prevents vascular atherosclerotic changes and decreases cardiovascular events in adulthood and emphasizes the importance of early detection and intervention in the pediatric FH patients group.

Summary

FH is a common genetic disease caused by mutations in genes associated with the metabolism of low-density lipoproteins (LDL). The hallmark of FH is elevated LDL cholesterol (LDL-C) levels from birth and premature atherosclerotic cardiovascular disease (ASCVD). Often FH is either undiagnosed or diagnosed with a considerable delay, leading to vascular atherosclerotic changes and cardiovascular disease. Prompt identification of FH subjects is essential, to initiate early preventive measures. Safe and efficient pharmacological agents are approved for use in children and adolescents. Statins are the first line of therapy, in combination of ezetimibe. Unfortunately, these drugs do not warrant the achievement of therapeutic target, especially in HoFH patient. In the latter, lipoprotein apheresis (LA), which has been shown to be safe and effective, is strongly recommended. Finally, the new drugs still under study will allow a multimodal customized treatment. Lowering cholesterol levels at a young age hinders vascular atherosclerotic changes decreasing cardiovascular events in adulthood. Therefore, early detection, diagnosis, and intervention in FH patients are priority objectives.

Feasibility and cost of FH cascade screening in Belgium (BEL-CASCADE) including a novel rapid rule-out strategy

BACKGROUND

Familial hypercholesterolaemia (FH) is underdiagnosed in most countries. We report our first experience from a national pilot project of cascade screening in relatives of FH patients.

METHODOLOGY

Participating specialists recruited consecutive index patients (IP) with Dutch Lipid Clinic Network (DLCN) score ≥6. After informed consent, the relatives were visited by the nurses to collect relevant clinical data and perform blood sampling for lipid profile measurement. FH diagnosis in the relatives was based on the DLCN and/or MEDPED FH (Make-Early-Diagnosis-to-Prevent-Early-Deaths-in-FH) criteria.

RESULTS

In a period of 18 months, a total of 127 IP (90 with definite FH and 37 with probable FH) were enrolled in 15 centres. Out of the 270 relatives visited by the nurses, 105 were suspected of having FH: 31 with DCLN score >8, 33 with DLCN score 5-8 and 41 with MEDPED FH criteria. In a post-hoc analysis, another set of MEDPED FH criteria established in the Netherlands and adapted to Belgium allowed to detect FH in 51 additional relatives.

CONCLUSION

In a country with no national FH screening program, our pilot project demonstrated that implementing a simple phenotypical FH cascade screening strategy using the collaboration of motivated specialists and two nurses, allowed to diagnose FH in 127 index patients and an additional 105 of their relatives over the two-year period. Newly developed MEDPED FH cut-offs, easily applicable by a nurse with a single blood sample, might further improve the sensitivity of detecting FH within families.

Systematic Identification of Familial Hypercholesterolaemia in Primary Care-A Systematic Review

Familial hypercholesterolaemia (FH) is a common inherited cause of premature cardiovascular disease, but the majority of patients remain undiagnosed. The aim of this systematic review was to assess the effectiveness of interventions to systematically identify FH in primary care. No randomised, controlled studies were identified; however, three non-randomised intervention studies were eligible for inclusion. All three studies systematically identified FH using reminders (on-screen prompts) in electronic health records. There was insufficient evidence that providing comments on laboratory test results increased the identification of FH using the Dutch Lipid Clinic Network (DLCN) criteria. Similarly, using prompts combined with postal invitation demonstrated no significant increase in definite FH identification using Simon-Broome (SB) criteria; however, the identification of possible FH increased by 25.4% (CI 17.75 to 33.97%). Using on-screen prompts alone demonstrated a small increase of 0.05% (95% CI 0.03 to 0.07%) in identifying definite FH using SB criteria; however, when the intervention was combined with an outreach FH nurse assessment, the result was no significant increase in FH identification using a combination of SB and DLCN criteria. None of the included studies reported adverse effects associated with the interventions. Currently, there is insufficient evidence to determine which is the most effective method of systematically identifying FH in non-specialist settings.

Lipoprotein metabolism in familial hypercholesterolemia

Familial hypercholesterolemia (FH) is one of the most common genetic disorders in humans. It is an extremely atherogenic metabolic disorder characterized by lifelong elevations of circulating LDL-C levels often leading to premature cardiovascular events. In this review, we discuss the clinical phenotypes of heterozygous and homozygous FH, the genetic variants in four genes (LDLR/APOB/PCSK9/LDLRAP1) underpinning the FH phenotype as well as the most recent in vitro experimental approaches used to investigate molecular defects affecting the LDL receptor pathway. In addition, we review perturbations in the metabolism of lipoproteins other than LDL in FH, with a major focus on lipoprotein (a). Finally, we discuss the mode of action and efficacy of many of the currently approved hypocholesterolemic agents used to treat patients with FH, with a special emphasis on the treatment of phenotypically more severe forms of FH.

Closing the gap: Identification and management of familial hypercholesterolemia in an integrated healthcare delivery system

BACKGROUND

Familial hypercholesterolemia (FH) is an autosomal dominant genetic disorder that causes markedly elevated risk for early onset coronary artery disease. Despite availability of effective therapy, only 5-10% of affected individuals worldwide are diagnosed.

OBJECTIVE

To develop and evaluate a novel approach for identifying and managing patients with FH in a large integrated health system with a diverse patient population, using inexpensive methods.

METHODS

Using Make Early Diagnosis/Prevent Early Death (MEDPED) criteria, we created a method for identifying patients at high risk for FH within the Kaiser Permanente Northern California electronic medical record. This led to a pragmatic workflow for contacting patients, establishing a diagnosis in a dedicated FH clinic, and initiating management. We prospectively collected data on the first 100 patients to assess implementation effectiveness.

RESULTS

Ninety-three (93.0%, 95%CI: 86.1%-97.1%) of the first 100 evaluated patients were diagnosed with FH (median age = 38 years) of whom only 5% were previously recognized; 48% were taking no lipid-lowering therapy, and 7% had acute coronary symptoms. 82 underwent successful genetic testing of whom 55 (67.1%; 95%CI: 55.8%-77.1%) had a pathogenic mutation. Following clinic evaluation, 83 of 85 (97.6%) medication-eligible patients were prescribed combination lipid-lowering therapy. 20 family members in the healthcare system were diagnosed with FH through cascade testing.

CONCLUSIONS

This novel approach was effective for identifying and managing patients with undiagnosed FH. Care gaps in providing appropriate lipid-lowering therapy were successfully addressed. Further development and dissemination of integrated approaches to FH care are warranted.

Familial Hypercholesterolemia: A Narrative Review on Diagnosis and Management Strategies for Children and Adolescents

Familial hypercholesterolemia (FH) is a relatively common inherited disorder caused by deleterious mutation(s) in the low-density lipoprotein (LDL) receptor or its associated genes. Given its nature as a heritable disease, any useful screening scheme, including universal, and cascade screening, allows for the early identification of patients with FH. Another important aspect to note is that early diagnosis associated with appropriate treatment can promote better prognosis. However, most clinical diagnostic criteria for adults have adopted clinical elements, such as physical xanthomas and family history, both of which are usually obscure and/or difficult to obtain in children and adolescents. Moreover, LDL cholesterol levels fluctuating considerably during adolescence, hindering the timely diagnosis of FH. In addition, recent advancements in human genetics have revealed several types of FH, including conventional monogenic FH, polygenic FH caused by common single nucleotide variations (SNV) accumulation associated with elevated LDL cholesterol, and oligogenic FH with multiple deleterious genetic variations leading to substantially elevated LDL cholesterol. The aforementioned findings collectively suggest the need for amassing information related to genetics and imaging, in addition to classical clinical elements, for the accurate diagnosis of FH in this era of personalized medicine. The current narrative review summarizes the current status of the clinical and genetic diagnosis of FH in children and adolescents, as well as provide useful management strategies for FH in children and adolescents based on currently available clinical evidence.

Familial hypercholesterolemia: Is there a role for PCSK9 and thrombin generation?

INTRODUCTION

Familial hypercholesterolemia (FH) is an autosomal dominant genetic disease. The prevalence of FH has previously been reported as 1 in 500 in the general population. This study aimed to evaluate the proprotein convertase subtilisin/kexin 9 (PCSK9) levels, lipid profile and thrombin generation in FH patients undergoing treatment or not.

METHODS

Eighty individuals with FH were selected and distributed in 2 groups: individuals treated with statins alone or conjugate therapy (statin + ezetimibe) (T = 53) and those non treated (NT = 27). PCSK9 levels were determined by ELISA, the lipid profile by colorimetric enzyme method and thrombin generation assay (TGA) by CAT method.

RESULTS

Individuals treated with conjugate therapy (statin + ezetimibe) showed a significant reduction in the levels of total cholesterol (TC) low density lipoprotein cholesterol (LDLc) and in the potential for thrombin generation (ETP with low and high concentration of tissue factor), compared to the treated individuals with monotherapy (statins). PCSK9 was positively correlated with increased levels of TC, LDLc and triglycerides, while TGA parameters were positively correlated with PCSK9 and lipid profile.

CONCLUSION

PCSK9 levels appear to be associated with components of the lipid and hemostatic profiles, in addition to being influenced by age. In general, our findings suggest that combined therapy for the treatment of FH is associated with a significant improvement in both lipid and hemostatic profiles assessed by TGA, suggesting a reduction in atherogenic and thrombogenic risks and, therefore, more promising compared to the use of statin monotherapy.

Validity and reliability of an adapted questionnaire measuring knowledge, awareness and practice regarding familial hypercholesterolaemia among primary care physicians in Malaysia

BACKGROUND

Primary care physicians (PCP) play an important role in detecting Familial Hypercholesterolaemia (FH) early. However, knowledge, awareness and practice (KAP) regarding FH among Malaysian PCP are not well established, and there was no validated tool to assess their FH KAP. Thus, the aim of this study was to adapt an FH KAP questionnaire and determine its validity and reliability among Malaysian PCP.

METHODS

This cross-sectional validation study involved Malaysian PCP with ≥ 1-year work experience in the primary care settings. In Phase 1, the original 19-item FH KAP questionnaire underwent content validation and adaptation by 7 experts. The questionnaire was then converted into an online survey instrument and was face validated by 10 PCP. In Phase 2, the adapted questionnaire was disseminated through e-mail to 1500 PCP. Data were collected on their KAP, demography, qualification and work experience. The construct validity was tested using known-groups validation method. The hypothesis was PCP holding postgraduate qualification (PCP-PG-Qual) would have better FH KAP compared with PCP without postgraduate qualification (PCP-noPG-Qual). Internal consistency reliability was calculated using Kuder Richardson formula-20 (KR-20) and test-retest reliability was tested on 26 PCP using kappa statistics.

RESULTS

During content validation and adaptation, 10 items remained unchanged, 8 items were modified, 1 item was moved to demography and 7 items were added. The adapted questionnaire consisted of 25 items (11 knowledge, 5 awareness and 9 practice items). A total of 130 out of 1500 PCP (response rate: 8.7%) completed the questionnaire. The mean percentage knowledge score was found to be significantly higher in PCP-PG-Qual compared with PCP-noPG-Qual (53.5, SD ± 13.9 vs. 35.9, SD ± 11.79), t(128) = 6.90, p < 0.001. The median percentage awareness score was found to be significantly higher in PCP-PG-Qual compared with PCP-noPG-Qual (15.4, IqR ± 23.08 vs. 7.7, IqR ± 15.38), p = 0.030. The mean percentage practice score was significantly higher in PCP-PG-Qual compared with PCP-noPG-Qual (69.2, SD ± 17.62 vs. 54.4, SD ± 19.28), t(128) = 3.79, p < 0.001. KR-20 value was 0.79 (moderate reliability) and average Kappa was 0.796 (substantial agreement).

CONCLUSION

This study has proven that the 25-item adapted FH KAP questionnaire is valid and reliable. It can be used to measure and establish FH KAP among PCP in Malaysia.

Lipid profile assessed in the family pediatrician's office: the COLIBRI'- SIMPeF study

There is limited information on the prevalence of dyslipidemia in the Italian pediatric population. Aim of the study was to evaluate total cholesterol, high-density lipoprotein (HDL)-cholesterol and triglyceride levels, and associated factors in a large sample of Italian children, applying a micro-sampling procedure in the family pediatrician's office. In a population of 1910 children (50.2% males, age 7-11 years), 27.6% was overweight or obese and 28.3% had at least one parent with referred hypercholesterolemia. Total cholesterol and triglyceride levels were elevated in 4.5% and 23.5% of the subjects, respectively, while HDL cholesterol was below 40 mg/dl in 3.3%. Male gender (OR 1.58, 95% CI 1.01-2.49) and positive family history (OR 2.13, 95% CI 1.36-3.32) were independent predictors of hypercholesterolemia, while BMI z-score was associated with low HDL cholesterol (OR 1.46, 95% CI 1.13-1.88) and high levels of triglycerides (OR 1.39, 95% CI 1.26-1.55).Conclusion: The prevalence of dyslipidemia in our sample is worthy of attention. The study suggests the opportunity and feasibility to check for the presence of dyslipidemia at the family pediatrician's office. Familiarity is associated with high cholesterol levels, regardless of the children's weight class, while weight excess identifies subjects with the typical lipid profile of metabolic syndrome. What is Known: • Few data are available on the lipid profile in Italian children. • Early treatment of hypercholesterolemia is effective in reducing cardiovascular events later in life; there is no agreement on how to screen for dyslipidemia in childhood, however. What is New: • In a large sample of Italian children, familiarity doubles the risk of hypercholesterolemia, while increased BMI is associated with low HDL cholesterol levels and hypertriglyceridemia. • The pediatrician may perform an assessment of plasma lipids in his office as a first step to diagnose familial hypercholesterolemia.

Management of Familial Hypercholesterolemia: Current Status and Future Perspectives

Familial hypercholesterolemia (FH) is the most common monogenic disorder associated with premature atherosclerotic cardiovascular disease. Early diagnosis and effective treatment can significantly improve prognosis. Recent advances in the field of lipid metabolism have shed light on the molecular defects in FH and new therapeutic options have emerged. A search of PubMed database up to March 2020 was performed for this review using the following keywords: "familial hypercholesterolemia," "diagnosis," "management," "guideline," "consensus," "genetics," "screening," "lipid lowering agents." The prevalence rate of heterozygous FH is approximately 1 in 200 to 250 and FH is underdiagnosed and undertreated in many parts of the world. Diagnostic criteria have been developed to aid the clinical diagnosis of FH. Genetic testing is now available but not widely used. Cascade screening is recommended to identify affected family members, and the benefits of early interventions are clear. Treatment strategy and target is currently based on low-density lipoprotein (LDL) cholesterol levels as the prognosis of FH largely depends on the magnitude of LDL cholesterol-lowering that can be achieved by lipid-lowering therapies. Statins with or without ezetimibe are the mainstay of treatment and are cost-effective. Addition of newer medications like PCSK9 inhibitors is able to further lower LDL cholesterol levels substantially, but the cost is high. Lipoprotein apheresis is indicated in homozygous FH or severe heterozygous FH patients with inadequate response to cholesterol-lowering therapies. In conclusion, FH is a common, treatable genetic disorder, and although our understanding of this disease has improved, many challenges still remain for its optimal management.

Advances with lipid-lowering drugs for pediatric patients with familial hypercholesterolemia

INTRODUCTION

Familial hypercholesterolemia (FH) is a frequent genetic disorder characterized by elevated LDL-cholesterol (LDL-C) and early onset of atherosclerosis.

AREAS COVERED

The authors provide an overview of the pediatric FH scenario, with emphasis on the role of statins as the preferred pharmacological therapy, discussing their potential benefits, as well as adverse effects, and the remaining uncertainties about their use in this population. They also comment on other lipid-lowering therapies.

EXPERT OPINION

Statin therapy is recommended after the ages of 8-10 years old for heterozygous FH patients and can reduce LDL-C by 24-50% depending on drug type and dosage. For more severe cases, higher doses and adjuvant therapies like ezetimibe may be necessary and treatment should be started at diagnosis, as is the case of homozygous FH. Statins reduce progression of subclinical vascular disease and may reduce early cardiovascular events. The available evidence indicates safety of statins in children with no apparent harms related to growth, sexual maturation, steroid hormones, glucose levels, cognitive function, or muscle and liver problems, in comparison with placebo. Newer treatments like lomitapide, PCSK9 inhibitors, bempedoic acid and evinacumab need to be adequately evaluated in pediatric FH patients with more severe dyslipidemia.

Prevalence of cardiovascular events in genetically confirmed versus unconfirmed familial hypercholesterolaemia

Introduction: Genetic testing for familial hypercholesterolaemia (FH) is not yet established for widespread use internationally to provide diagnostic confirmation, in part due to high cost and resource requirement. We need to establish whether genetic testing is clinically justified in terms of risk stratification and prediction of cardiovascular events. Methods:We performed a single tertiary cardiac centre retrospective evaluation of patients with FH managed within our genetic screening service. We evaluated the prevalence of cardiovascular events in genetically confirmed cases of FH compared to those unconfirmed upon genetic testing, to assess whether gene positivity confers a higher risk phenotype. We also compared the clinical characteristics of the genetically confirmed and unconfirmed group. Results:Amongst adult patients (≥18 years) with genetically confirmed heterozygous FH (n=87), 34% (30/87) had one or more documented CV events. In comparison a lower event rate was observed in adult patients with genetically unconfirmed FH (n=170) with 25% (42/170) experiencing one or more documented CV events. Additional cardiovascular risk factors were more prevalent in the unconfirmed group including hypertension, co-morbidities, higher age and body mass index which may have modified the difference in cardiovascular risk. Conclusion:Genetic testing in FH may be clinically justified and appears to identify a subset of patients with higher risk of cardiovascular events. However, the risk difference is modified by alternative cardiovascular risk factors and co-morbidities which may be more prevalent in genetically unconfirmed FH.

Cascade screening and genetic diagnosis of familial hypercholesterolemia in clusters of the Southeastern region from Brazil

Familial hypercholesterolemia (FH) is an autosomal dominant genetic disease characterized by high levels of low-density lipoprotein-cholesterol (LDLc), associated to premature cardiovascular disease. The detection of the variants related to FH is important to improve the early diagnosis in probands / index-cases (ICs) and their relatives. We included ICs with FH and their relatives, living in a small region of Minas Gerais state-Brazil, which were classified according to Dutch Lipid Clinic Network Criteria (DLCNC) and submitted to sequencing of genes related to FH (LDLR, APOB, PCSK9, LDLRAP1, LIPA, STAP1, APOE, ABCG5 e ABCG8). In a total of 143 subjects (32 ICs and 111 relatives), eight variants were identified in 91 individuals. From these variants, five were in LDLR [p.(Asp224Asn), p.(Ser854Gly), p.(Cys34Arg), p.(Asp601His), deletion of exon15 in LDLR)], one in APOB [p.(Met499Val)], one in PCSK9 [p.(Arg237Trp)] and one in APOE [p.(Pro28Leu)] genes. The variants were detected in 100% of those subjects classified as definitive, 87% as probable and 69% as possible FH cases based on DLCNC. The LDLc level was higher in individuals with corneal arch and xanthomas or xanthelasmas, as well as in pathogenic or probably pathogenic variants carriers. This study showed higher frequency of LDLR gene variants compared to other genes related to LDL metabolism in individuals with FH in Minas Gerais - Brazil and the presence of FH in relatives without previous diagnosis. Our data reinforce the importance of molecular and clinical evaluation of FH relatives in order to early diagnosis the FH, as well as cardiovascular diseases prevention.

Evaluating a clinical tool (FAMCAT) for identifying familial hypercholesterolaemia in primary care: a retrospective cohort study

Background

Familial hypercholesterolaemia (FH) is an inherited lipid disorder causing premature heart disease, which is severely underdiagnosed. Improving the identification of people with FH in primary care settings would help to reduce avoidable heart attacks and early deaths.

Aim

To evaluate the accuracy of the familial hypercholesterolaemia case ascertainment identifcation tool (FAMCAT) for identifying FH in primary care.

Design & setting

A retrospective cohort study of 1 030 183 patients was undertaken. Data were extracted from the UK Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC) database. Patient were aged >16 years.

Method

The FAMCAT algorithm was compared with methods of FH detection recommended by national guidelines (Simon Broome diagnostic criteria, Dutch Lipid Clinic Network [DLCN] Score, and cholesterol levels >99^th centile). Discrimination and calibration were assessed by area under the receiver operating curve (AUC) and by comparing observed versus predicted cases.

Results

A total of 1707 patients had a diagnosis of FH. FAMCAT showed a high level of discrimination (AUC = 0.844, 95% confidence interval [CI] = 0.834 to 0.854), performing significantly better than Simon Broome criteria (AUC = 0.730, 95% CI = 0.719 to 0.741), DLCN Score (AUC = 0.766, 95% CI = 0.755 to 0.778), and screening cholesterols >99 th centile (AUC = 0.579, 95% CI = 0.571 to 0.588). Inclusion of premature myocardial infarction (MI) and fitting cholesterol as a continuous variable improved the accuracy of FAMCAT (AUC = 0.894, 95% CI = 0.885 to 0.903).

Conclusion

Better performance of the FAMCAT algorithm, compared with other approaches for case finding of FH in primary care, such as Simon Broome criteria, DLCN criteria or very high cholesterol levels, has been confirmed in a large population cohort.

A reassessment of the Japanese clinical diagnostic criteria of familial hypercholesterolemia in a hospital-based cohort using comprehensive genetic analysis

Background

Clinical diagnostic criteria of familial hypercholesterolemia (FH) in Japan include LDL cholesterol ​≥ ​180 ​mg/dL, Achilles tendon thickness ​≥ ​9.0 ​mm, and family history. However, few data exist regarding its validation.

Design and Methods

A series of 680 participants, with a mean LDL cholesterol of 175 ​mg/dL were enrolled at Kanazawa University Hospital between 2006 and 2018. All had full assessments of, LDL cholesterol, Achilles tendon X-rays, family history records, and genetic analysis of FH-associated genes (LDLR, APOB, and PCSK9). The area under the curve (AUC) of receiver operating characteristic (ROC) curve analysis predicting the presence of FH mutations by each clinical marker were assessed.

Results

The optimal cutoff values predicting the presence of an FH-associated mutation were 181 ​mg/dL for LDL cholesterol and ≥7.0 ​mm for Achilles tendon thickness. AUCs predicting FH mutations were 0.827 for Achilles tendon thickness ≥9.0 ​mm, 0.889 for LDL cholesterol ≥180 ​mg/dL, and 0.906 for family history. If Achilles tendon thickness ≥7.0 ​mm was used as a clinical criterion, then 41 participants (6%) were newly diagnosed with FH and 86 (12%) were newly misclassified as FH.

Conclusions

Current clinical diagnostic criteria of FH were validated in this cohort. We recommend considering a tentative diagnosis of “potential FH” if the Achilles tendon thickness is ​≥ ​7.0 ​mm and <9.0 ​mm rather than dismissing a diagnosis of FH.

•

Clinical diagnostic criteria of FH in Japan were well validated.

•

The best cutoff value of ATT for predicting FH mutation was 7.0 ​mm.

•

Threshold of ATT ≥7.0 ​mm increased the sensitivity to diagnose FH.

Performance and clinical utility of supervised machine-learning approaches in detecting familial hypercholesterolaemia in primary care

Familial hypercholesterolaemia (FH) is a common inherited disorder, causing lifelong elevated low-density lipoprotein cholesterol (LDL-C). Most individuals with FH remain undiagnosed, precluding opportunities to prevent premature heart disease and death. Some machine-learning approaches improve detection of FH in electronic health records, though clinical impact is under-explored. We assessed performance of an array of machine-learning approaches for enhancing detection of FH, and their clinical utility, within a large primary care population. A retrospective cohort study was done using routine primary care clinical records of 4,027,775 individuals from the United Kingdom with total cholesterol measured from 1 January 1999 to 25 June 2019. Predictive accuracy of five common machine-learning algorithms (logistic regression, random forest, gradient boosting machines, neural networks and ensemble learning) were assessed for detecting FH. Predictive accuracy was assessed by area under the receiver operating curves (AUC) and expected vs observed calibration slope; with clinical utility assessed by expected case-review workload and likelihood ratios. There were 7928 incident diagnoses of FH. In addition to known clinical features of FH (raised total cholesterol or LDL-C and family history of premature coronary heart disease), machine-learning (ML) algorithms identified features such as raised triglycerides which reduced the likelihood of FH. Apart from logistic regression (AUC, 0.81), all four other ML approaches had similarly high predictive accuracy (AUC > 0.89). Calibration slope ranged from 0.997 for gradient boosting machines to 1.857 for logistic regression. Among those screened, high probability cases requiring clinical review varied from 0.73% using ensemble learning to 10.16% using deep learning, but with positive predictive values of 15.5% and 2.8% respectively. Ensemble learning exhibited a dominant positive likelihood ratio (45.5) compared to all other ML models (7.0-14.4). Machine-learning models show similar high accuracy in detecting FH, offering opportunities to increase diagnosis. However, the clinical case-finding workload required for yield of cases will differ substantially between models.

Measuring the contribution of Lp(a) cholesterol towards LDL-C interpretation

BACKGROUND

Lipoprotein(a) [Lp(a)] is a pro-atherogenic and pro-thrombotic LDL-like particle recognized as an independent risk factor for cardiovascular disease (CVD). The cholesterol within Lp(a) (Lp(a)-C) contributes to the reported LDL-cholesterol (LDL-C) concentration by nearly all available methods. Accurate LDL-C measurements are critical for identification of genetic dyslipidemias such as familial hypercholesterolemia (FH). FH diagnostic criteria, such as the Dutch Lipid Clinic Network (DLCN) criteria, utilize LDL-C concentration cut-offs to assess the likelihood of FH. Therefore, failure to adjust for Lp(a)-C can impact accurate FH diagnosis and classification, appropriate follow-up testing and treatments, and interpretation of cholesterol-lowering treatment efficacy.

OBJECTIVE

In this study, we use direct Lp(a)-C measurements to assess the potential misclassification of FH from contributions of Lp(a)-C to reported LDL-C in patient samples submitted for advanced lipoprotein profiling.

METHODS

A total of 31,215 samples submitted for lipoprotein profiling were included. LDL-C was measured by beta quantification or calculated by one of three equations. Lp(a)-C was measured by quantitative lipoprotein electrophoresis. DLCN LDL-C cut-offs were applied to LDL-C results before and after accounting for Lp(a)-C contribution.

RESULTS

Lp(a)-C was detected in 8665 (28%) samples. A total of 940 subjects were reclassified to a lower DLCN LDL-C categories; this represents 3% of the total patient series or 11% of subjects with measurable Lp(a)-C.

CONCLUSION

Lp(a)-C is present in a significant portion of samples submitted for advanced lipid testing and could cause patient misclassification when using FH diagnostic criteria. These misclassifications could trigger inappropriate follow-up, treatment, and cascade testing for suspected FH.

Awareness, treatment rates, and compliance to treatment in patients with serum LDL cholesterol higher than 250 mg/dL, and possible, probable, or definite familial hypercholesterolemia

PURPOSE

Familial hypercholesterolemia (FH) is a genetic disease characterized by increased levels of low-density lipoprotein cholesterol (LDL-C). It is underdiagnosed and undertreated despite relatively high prevalance and significant association with increased mortality. We aimed to determine treatment status and compliance in patients with LDL-C ≥ 250 mg/dL and FH.

DESIGN

Patients older than 18 years old and have a serum LDL-C ≥ 250 mg/dL between January 2010 to December 2016 were identified from the hospital database. A phone survey was performed. Demographic features, smoking status, alcohol use, exercise, cardiovascular disease (CVD), use of medication for dyslipidemia, and CVD and high cholesterol levels in the family were questioned. Dutch Lipid Clinical Network Criteria was used to classify patients. The study was registered to Clinicaltrials.gov in July 2020 (NCT04494464).

RESULTS

1365 patients with a LDL-C ≥ 250 mg/dL were identified. Patients that could not be reached and who refused to interview were excluded and the data of 367 patients were analyzed. There were 248 (67.6%) female and 119 (32.4%) male patients and mean age was 50.52 ± 11.66. LDL-C was ≥330 mg/dL in 50 (13.6%) and 250-329 mg/dL in 317 (86.4%) patients. Forty (10.9%) patients were classified as definite, 181 (49.3%) as probable and 146 (39.8%) as possible FH. 213 (58.0%) patients were not receiving lipid-lowering treatment, and 162 (76.1%) stated that medication was never recommended previously, 30 (14.1%) had stopped medication him/herself and 21 (9.8%) had stopped medication with the advice of the physician. Among patients with definite/probable FH, 84 (38.0%) had CVD and the rate of lipid-lowering drug use in these patients was 58.3%.

CONCLUSION

A significant proportion of patients with LDL-C ≥ 250 mg/dL were not taking lipid-lowering drugs. Similar with many other studies, diagnosis, and treatment rates of FH patients were very low in our study. Further national studies are required to increase awareness of the disease in both physicians and patients.

2019 George Lyman Duff Memorial Lecture: Three Decades of Examining DNA in Patients With Dyslipidemia

Dyslipidemias include both rare single gene disorders and common conditions that have a complex underlying basis. In London, ON, there is fortuitous close physical proximity between the Lipid Genetics Clinic and the London Regional Genomics Centre. For >30 years, we have applied DNA sequencing of clinical samples to help answer scientific questions. More than 2000 patients referred with dyslipidemias have participated in an ongoing translational research program. In 2013, we transitioned to next-generation sequencing; our targeted panel is designed to concurrently assess both monogenic and polygenic contributions to dyslipidemias. Patient DNA is screened for rare variants underlying 25 mendelian dyslipidemias, including familial hypercholesterolemia, hepatic lipase deficiency, abetalipoproteinemia, and familial chylomicronemia syndrome. Furthermore, polygenic scores for LDL (low-density lipoprotein) and HDL (high-density lipoprotein) cholesterol, and triglycerides are calculated for each patient. We thus simultaneously document both rare and common genetic variants, allowing for a broad view of genetic predisposition for both individual patients and cohorts. For instance, among patients referred with severe hypertriglyceridemia, defined as ≥10 mmol/L (≥885 mg/dL), <1% have a mendelian disorder (ie, autosomal recessive familial chylomicronemia syndrome), ≈15% have heterozygous rare variants (a >3-fold increase over normolipidemic individuals), and ≈35% have an extreme polygenic score (a >3-fold increase over normolipidemic individuals). Other dyslipidemias show a different mix of genetic determinants. Genetic results are discussed with patients and can support clinical decision-making. Integrating DNA testing into clinical care allows for a bidirectional flow of information, which facilitates scientific discoveries and clinical translation.

Efficacy and safety of statin use in children and adolescents with familial hypercholesterolaemia: a systematic review and meta-analysis of randomized-controlled trials

PURPOSE

Statins are the mainstay of treatment for patients with familial hypercholesterolaemia (FH). However, their efficacy and safety in children and adolescents with FH has not been well-documented. The purpose of this study was to systematically investigate and meta-analyze the best available evidence from randomized-controlled trials (RCTs) regarding the efficacy and safety of statins in this population.

METHODS

A comprehensive search was conducted in PubMed, Scopus and Cochrane, up to 10 January 2020. Data were expressed as mean differences with 95% confidence intervals (CI). The I2 index was employed for heterogeneity.

RESULTS

Ten RCTs were included in the qualitative and quantitative analysis (1191 patients, aged 13.3 ± 2.5 years). Compared with placebo, statins led to a mean relative reduction in total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglyceride and apolipoprotein B (apo-B) concentrations by -25.5% (95% CI -30.4%, -20.5%; I2 91%), -33.8% (95% CI -40.1%, -27.4%; I2 90%), -8.4% (95% CI -14.8%, -2.03%; I2 26%) and -28.8% (95% CI -33.9%, -23.6%; I2 83%), respectively. High-density lipoprotein cholesterol (HDL-C) was increased by 3.1% (95% CI 1.1%-5.2%; I2 0%). Statins were well-tolerated, with no significant differences in transaminase and creatine kinase levels or other adverse effects compared with placebo. Statins exerted no effect on growth or sexual development.

CONCLUSION

Statins are quite effective in reducing TC, LDL-C, TG and apo-B and increasing HDL-C concentrations in children and adolescents with FH. No safety issues were seen with statin use.

Next-generation sequencing to confirm clinical familial hypercholesterolemia

BACKGROUND

Familial hypercholesterolemia is characterised by high low-density lipoprotein-cholesterol levels and is caused by a pathogenic variant in LDLR, APOB or PCSK9. We investigated which proportion of suspected familial hypercholesterolemia patients was genetically confirmed, and whether this has changed over the past 20 years in The Netherlands.

METHODS

Targeted next-generation sequencing of 27 genes involved in lipid metabolism was performed in patients with low-density lipoprotein-cholesterol levels greater than 5 mmol/L who were referred to our centre between May 2016 and July 2018. The proportion of patients carrying likely pathogenic or pathogenic variants in LDLR, APOB or PCSK9, or the minor familial hypercholesterolemia genes LDLRAP1, ABCG5, ABCG8, LIPA and APOE were investigated. This was compared with the yield of Sanger sequencing between 1999 and 2016.

RESULTS

A total of 227 out of the 1528 referred patients (14.9%) were heterozygous carriers of a pathogenic variant in LDLR (80.2%), APOB (14.5%) or PCSK9 (5.3%). More than 50% of patients with a Dutch Lipid Clinic Network score of 'probable' or 'definite' familial hypercholesterolemia were familial hypercholesterolemia mutation-positive; 4.8% of the familial hypercholesterolemia mutation-negative patients carried a variant in one of the minor familial hypercholesterolemia genes. The mutation detection rate has decreased over the past two decades, especially in younger patients in which it dropped from 45% in 1999 to 30% in 2018.

CONCLUSIONS

A rare pathogenic variant in LDLR, APOB or PCSK9 was identified in 14.9% of suspected familial hypercholesterolemia patients and this rate has decreased in the past two decades. Stringent use of clinical criteria algorithms is warranted to increase this yield. Variants in the minor familial hypercholesterolemia genes provide a possible explanation for the familial hypercholesterolemia phenotype in a minority of patients.

Next-generation sequencing to confirm clinical familial hypercholesterolemia

BACKGROUND

Familial hypercholesterolemia is characterised by high low-density lipoprotein-cholesterol levels and is caused by a pathogenic variant in LDLR, APOB or PCSK9. We investigated which proportion of suspected familial hypercholesterolemia patients was genetically confirmed, and whether this has changed over the past 20 years in The Netherlands.

METHODS

Targeted next-generation sequencing of 27 genes involved in lipid metabolism was performed in patients with low-density lipoprotein-cholesterol levels greater than 5 mmol/L who were referred to our centre between May 2016 and July 2018. The proportion of patients carrying likely pathogenic or pathogenic variants in LDLR, APOB or PCSK9, or the minor familial hypercholesterolemia genes LDLRAP1, ABCG5, ABCG8, LIPA and APOE were investigated. This was compared with the yield of Sanger sequencing between 1999 and 2016.

RESULTS

A total of 227 out of the 1528 referred patients (14.9%) were heterozygous carriers of a pathogenic variant in LDLR (80.2%), APOB (14.5%) or PCSK9 (5.3%). More than 50% of patients with a Dutch Lipid Clinic Network score of 'probable' or 'definite' familial hypercholesterolemia were familial hypercholesterolemia mutation-positive; 4.8% of the familial hypercholesterolemia mutation-negative patients carried a variant in one of the minor familial hypercholesterolemia genes. The mutation detection rate has decreased over the past two decades, especially in younger patients in which it dropped from 45% in 1999 to 30% in 2018.

CONCLUSIONS

A rare pathogenic variant in LDLR, APOB or PCSK9 was identified in 14.9% of suspected familial hypercholesterolemia patients and this rate has decreased in the past two decades. Stringent use of clinical criteria algorithms is warranted to increase this yield. Variants in the minor familial hypercholesterolemia genes provide a possible explanation for the familial hypercholesterolemia phenotype in a minority of patients.

The Prevalence of Familial Hypercholesterolemia (FH) in Chinese Patients With Acute Myocardial Infarction (AMI): Data From Chinese Acute Myocardial Infarction (CAMI) Registry

Background: The prevalence of familial hypercholesterolemia (FH) in the patients with acute myocardial infarction (AMI) in China is unclear. Materials and Methods: In China Acute Myocardial Infarction (CAMI) Registry, 13,002 patients with age 18-80 were consecutively enrolled with first-onset AMI who were naïve to statin before admission from January 1st, 2013 to October 31st, 2014. According to Dutch Lipid Clinical Network Criteria (DLCNC), the patients were divided to heterozygous familial hypercholesterolemia (HeFH) (definite/probable HeFH, possible HeFH) or non-HeFH group. Results: The number of the patients in the three groups was as following, 62 in definite/probable HeFH group, 484 in possible HeFH group, 12,456 in non-HeFH group. The prevalence of HeFH is 4.2% (including 0.47% of definite/probable HeFH, 3.73% of possible FH). The average age of onset of first-time AMI was 54 ± 12, 56 ± 12, 63 ± 12 years old (p < 0.0001) in definite/probable HeFH group, possible HeFH group and non-HeFH group, respectively. The percentage of Killip III or above (8.1 vs. 4.3 vs. 6.3%, p = 0.1629), cardiac arrest (1.6 vs. 0.6 vs. 0.9%, p = 0.6990), and TIMI 0-2 grade after primary percutaneous cardiac intervention (PCI) (0 vs. 6.8 vs. 4.3%, p = 0.5866) was not significantly different in definite/probable HeFH group, possible HeFH group and non-HeFH group, respectively. Conclusions: The prevalence of HeFH in Chinese patients with AMI is 4.2%. The patients were significantly younger in HeFH group, when compared with those with non-HeFH. However, no significant differences were found in the severity of clinical manifestations in both HeFH and non-HeFH group.

The Prevalence and Diagnostic Ratio of Familial Hypercholesterolemia (FH) and Proportion of Acute Coronary Syndrome in Japanese FH Patients in a Healthcare Record Database Study

Background

Familial hypercholesterolemia (FH) is a genetic disorder characterized by high levels of low-density lipoprotein cholesterol (LDL-C). Because of underdiagnosis, acute coronary syndrome (ACS) is often the first clinical manifestation of FH. In Japan, there are few reports on the prevalence and diagnostic ratios of FH and the proportion of ACS among FH patients in clinical settings.

Methods

This retrospective, observational study used anonymized data from electronic healthcare databases between April 2001 and March 2015 of patients who had ≥2 LDL-C measurements recorded after April 2009. The index date was defined as the date of the first LDL-C measurement after April 2009. The primary endpoint was the prevalence of definite or suspected FH; secondary endpoints included the proportion of FH patients hospitalized for ACS, the proportion of patients using lipid-lowering drugs (LLDs), and LDL-C levels.

Results

Of the 187,781 patients screened, 1547 had definite or suspected FH (0.8%) based on data from the entire period; 832 patients with definite (n = 299, 0.16%) or suspected FH (n = 533, 0.28%) before the index date were identified in the main analysis cohort. LLDs were used in 214 definite FH patients (71.6%) and 137 suspected FH patients (25.7%). Among definite or suspected FH patients with ACS (n = 84) and without ACS (n = 748), 32.1% and 30.1% with definite FH and 3.2% and 2.4% with suspected FH had LDL-C levels < 2.6 mmol/L (<100 mg/dL), respectively. Sixty patients (7.2%) were hospitalized due to ACS at the index date.

Conclusions

The prevalence of FH in this Japanese cohort of patients with ≥2 LDL-C measurements at hospitals was 0.8%, which is higher than that currently reported in epidemiological studies (0.2-0.5%). Patients with suspected FH, with or without ACS, had poorly controlled LDL-C levels and were undertreated. The proportion of FH patients who were hospitalized due to ACS was 7.2%.

Detection of familial hypercholesterolaemia: external validation of the FAMCAT clinical case-finding algorithm to identify patients in primary care

BACKGROUND

The vast majority of individuals with familial hypercholesterolaemia in the general population remain unidentified worldwide. Recognising patients most likely to have the condition, to enable targeted specialist assessment and treatment, could prevent major coronary morbidity and mortality. We aimed to evaluate a clinical case-finding algorithm, the familial hypercholesterolaemia case ascertainment tool (FAMCAT), and compare it with currently recommended methods for detection of familial hypercholesterolaemia in primary care.

METHODS

In this external validation study, FAMCAT regression equations were applied to a retrospective cohort of patients aged 16 years or older with cholesterol assessed, who were randomly selected from 1500 primary care practices across the UK contributing to the QResearch database. In the main analysis, we assessed the ability of FAMCAT to detect familial hypercholesterolaemia (ie, its discrimination) and compared it with that of other established clinical case-finding approaches recommended internationally (Simon Broome, Dutch Lipid Clinic Network, Make Early Diagnosis to Prevent Early Deaths [MEDPED] and cholesterol concentrations higher than the 99th percentile of the general population in the UK). We assessed discrimination by area under the receiver operating curve (AUROC; ranging from 0·5, indicating pure chance, to 1, indicating perfect discrimination). Using a probability threshold of more than 1 in 500 (prevalence of familial hypercholesterolaemia), we also assessed sensitivity, specificity, positive predictive values, and negative predictive values in the main analysis.

FINDINGS

A sample of 750 000 patients who registered in 1500 UK primary care practices that contribute anonymised data to the QResearch database between Jan 1, 1999, and Sept 1, 2017, was randomly selected, of which 747 000 patients were assessed. FAMCAT showed a high degree of discrimination (AUROC 0·832, 95% CI 0·820-0·845), which was higher than that of Simon Broome criteria (0·694, 0·681-0·703), Dutch Lipid Clinic Network criteria (0·724, 0·710-0·738), MEDPED criteria (0·624, 0·609-0·638), and screening cholesterol concentrations higher than the 99th percentile (0·581, 0·570-0·591). Using a 1 in 500 probability threshold, FAMCAT achieved a sensitivity of 84% (1028 predicted vs 1219 observed cases) and specificity of 60% (443 949 predicted vs 745 781 observed non-cases), with a corresponding positive predictive value of 0·84% and a negative predictive value of 99·2%.

INTERPRETATION

FAMCAT identifies familial hypercholesterolaemia with greater accuracy than currently recommended approaches and could be considered for clinical case finding of patients with the highest likelihood of having hypercholesterolaemia in primary care.

FUNDING

UK National Institute for Health Research School for Primary Care Research.

Identifying Familial Hypercholesterolemia Using a Blood Donor Screening Program With More Than 1 Million Volunteer Donors

Importance

Familial hypercholesterolemia is an autosomal-dominant disorder that often causes premature coronary artery disease. Unfortunately, familial hypercholesterolemia remains largely undiagnosed.

Objective

To estimate the prevalence of familial hypercholesterolemia in a population of blood donors.

Design

This analysis of deidentified data from blood donors 16 years and older who donated to Carter BloodCare, one of the largest independent blood programs in the United States, between January 2002 and December 2016. Carter BloodCare, which serves a population of about 8 million in Texas, routinely measures total nonfasting serum cholesterol levels as part of a donor health screening program. Data analysis occurred from October 2017 to March 2019.

Exposure

Blood donation.

Main Outcomes and Measures

Familial hypercholesterolemia was defined using the Make Early Diagnosis to Prevent Early Death general population criteria, with total nonfasting serum cholesterol thresholds of 270, 290, 340, and 360 mg/dL for donors younger than 20 years, 20 to 29 years, 30 to 39 years, and 40 years or older, respectively (to convert cholesterol values to mmol/L, multiply by 0.0259). For repeated donors, the maximum observed total cholesterol level was used for analyses.

Results

The study included 1 178 102 individual donors with a total of 3 038 420 blood donations. Of all individual donors (median total cholesterol level, 183 [interquartile range (IQR), 157-212] mg/dL; median age, 32 [IQR, 19-47] years; 619 583 [52.6%] women), a total of 3473 individuals (or 1 in every 339) met criteria for familial hypercholesterolemia. This group had a median (IQR) total cholesterol of 332 (297-377) mg/dL. Estimated prevalence was higher at younger ages (<30 years: 1:257) compared with older ages (≥30 years: 1:469; P < .001) and in men (1:327) compared with women (1:351; P = .03). Among 2219 repeated donors who met familial hypercholesterolemia criteria at least once, 3116 of 10 833 total donations (28.8%) met FH criteria.

Conclusions and Relevance

The prevalence of familial hypercholesterolemia using the Make Early Diagnosis to Prevent Early Death criteria in a large cohort of blood donors was similar to the estimated prevalence of this disorder in the general population. The blood donor screening program could be a novel strategy to detect and notify individuals with potential familial hypercholesterolemia, particularly younger individuals in whom early detection and treatment is especially helpful, as well as guide cascade screening.

The characteristics of patients with possible familial hypercholesterolemia-screening a large payer/provider healthcare delivery system

BACKGROUND

Familial hypercholesterolemia (FH) is an under-diagnosed condition.

AIM

We applied standard laboratory criteria across a large longitudinal electronic medical record database to describe cross-sectional population with possible FH.

METHODS

A cross-sectional study of Clalit Health Services members. Subjects who met the General Population MED-PED laboratory criteria, excluding: age <10 years, documentation of thyroid, liver, biliary or autoimmune diseases, a history of chronic kidney disease stage 3 or greater, the presence of urine protein >300 mg/l, HDL-C>80 mg/dl, active malignancy or pregnancy at the time of testing were considered possible FH. Demographic and clinical characteristics are described at time of diagnosis and at a single index date following diagnosis to estimate the burden on the healthcare system. The patient population is also compared to the general population.

RESULTS

The study cohort included 12 494 subjects with out of over 4.5 million members of Clalit Health Services. The estimated prevalence of FH in Israel was found to be 1:285. These patients are notably positive for, and have a family history of, cardiovascular disease and risk factors. For most of them the LDL-C levels are not controlled, and only a quarter of them are medically treated.

CONCLUSIONS

By using the modified MED-PED criteria in a large electronic database, patients with possible FH can be identified enabling early intervention and treatment.