Global perspective of familial hypercholesterolaemia: a cross-sectional study from the EAS Familial Hypercholesterolaemia Studies Collaboration (FHSC)

Identification of New Copy Number Variation and the Evaluation of a CNV Detection Tool for NGS Panel Data in Polish Familial Hypercholesterolemia Patients

Familial hypercholesterolemia (FH) is an inherited, autosomal dominant metabolic disorder mostly associated with disease-causing variant in LDLR, APOB or PCSK9. Although the dominant changes are small-scale missense, frameshift and splicing variants, approximately 10% of molecularly defined FH cases are due to copy number variations (CNVs). The first-line strategy is to identify possible pathogenic SNVs (single nucleotide variants) using multiple PCR, Sanger sequencing, or with more comprehensive approaches, such as NGS (next-generation sequencing), WES (whole-exome sequencing) or WGS (whole-genome sequencing). The gold standard for CNV detection in genetic diagnostics are MLPA (multiplex ligation-dependent amplification) or aCGH (array-based comparative genome hybridization). However, faster and simpler analyses are needed. Therefore, it has been proposed that NGS data can be searched to analyze CNV variants. The aim of the study was to identify novel CNV changes in FH patients without detected pathogenic SNVs using targeted sequencing and evaluation of CNV calling tool (DECoN) working on gene panel NGS data; the study also assesses its suitability as a screening step in genetic diagnostics. A group of 136 adult and child patients were recruited for the present study. The inclusion criteria comprised at least “possible FH” according to the Simon Broome diagnostic criteria in children and the DLCN (Dutch Lipid Clinical Network) criteria in adults. NGS analysis revealed potentially pathogenic SNVs in 57 patients. Thirty selected patients without a positive finding from NGS were subjected to MLPA analysis; ten of these revealed possibly pathogenic CNVs. Nine patients were found to harbor exons 4−8 duplication, two harbored exons 6−8 deletion and one demonstrated exon 9−10 deletion in LDLR. To test the DECoN program, the whole study group was referred for bioinformatic analysis. The DECoN program detected duplication of exons 4−8 in the LDLR gene in two patients, whose genetic analysis was stopped after the NGS step. The integration of the two methods proved to be particularly valuable in a five-year-old girl presenting with extreme hypercholesterolemia, with both a pathogenic missense variant (c.1747C>T) and exons 9−10 deletion in LDLR. This is the first report of a heterozygous deletion of exons 9 and 10 co-occurring with SNV. Our results suggest that the NGS-based approach has the potential to identify large-scale variation in the LDLR gene and could be further applied to extend CNV screening in other FH-related genes. Nevertheless, the outcomes from the bioinformatic approach still need to be confirmed by MLPA; hence, the latter remains the reference method for assessing CNV in FH patients.

What should be the goal of cholesterol-lowering treatment? A quantitative evaluation dispelling guideline myths

PURPOSE OF REVIEW

Guidelines for cholesterol-lowering treatment generally include extensive review of epidemiological and clinical trial evidence. However, the next logical step, the translation of evidence into clinical advice, occurs not entirely by reasoning, but by a form of consensus in which the prejudices and established beliefs of the societies with interests in cardiovascular disease convened to interpret the evidence are prominent. Methods, which are the subject of this review, have, however, been developed by which clinical trial evidence can be translated objectively into best practice.

RECENT FINDINGS

Guidelines differ in their recommended goals for cholesterol-lowering treatment in the prevention of atherosclerotic cardiovascular disease (ASCVD). Proposed goals are LDL-cholesterol 2.6 mmol/l (100 mg/dl) or less in lower risk, LDL-cholesterol 1.8 mmol/l (70 mg/dl) or less in higher risk, non-HDL-cholesterol decrease of at least 40% or LDL-cholesterol 1.8 mmol/l (70 mg/dl) or less or decreased by at least 50% whichever is lower. Evidence from clinical trials of statins, ezetimibe and proprotein convertase subtilisin/kexin type 9-inhibitors can be expressed in simple mathematical terms to compare the efficacy on ASCVD incidence of clinical guidance for the use of cholesterol-lowering medication. The target LDL-cholesterol of 2.6 mmol/l (100 mg/dl) is ineffective and lacks credibility. Cholesterol-lowering medication is most effective in high-risk people with raised LDL-cholesterol. The best overall therapeutic target is LDL-cholesterol 1.8 mmol/l (70 mg/dl) or less or decreased by at least 50% whichever is lower. The use of non-HDL-cholesterol as a therapeutic goal is less efficacious. Aiming for LDL-cholesterol 1.4 mmol/l (55 mg/dl) or less as opposed to 1.8 mmol/l produces only a small additional benefit. Evidence for apolipoprotein B targets in hypertriglyceridaemia and in very high ASCVD risk should be more prominent in future guidelines.

SUMMARY

The LDL-cholesterol goal of 2.6 mmol/l or less should be abandoned. Percentage decreases in LDL-cholesterol or non-HDL-cholesterol concentration are better in people with initial concentrations of less than 3.6 mmol/l. The LDL-cholesterol target of 1.8 mmol/l is most effective when initial LDL-cholesterol is more than 3.6 mmol/l in both primary and secondary prevention.

Universal screening for familial hypercholesterolemia in 2 populations

PURPOSE

In Europe, >2 million individuals with familial hypercholesterolemia (FH) are currently undiagnosed. Effective screening strategies for FH diagnosis in childhood are urgently needed. We assessed the overall performances of 2 different FH screening programs in children: universal screening program with opt-out and opt-in type participation.

METHODS

We analyzed the data from 2 independent populations based on >166,000 individuals screened for hypercholesterolemia. Genetic analyses of FH-related genes were finalized in 945 children and 99 parents.

RESULTS

A total of 305 (32.3%) children were genotyped as positive or with a variant of uncertain significance in FH-related genes. For low-density lipoprotein cholesterol levels of 3.5 mmol L (135.3 mg/dL), the overall sensitivity and specificity for confirming FH were 90.5% and 55.3%, respectively. As part of child-parent screening, in >90% of the families, the parent with reported higher cholesterol levels was positive for the familial genetic variant. The cohort-based prevalence of FH from the opt-out universal screening program was estimated to be 1 in 431 individuals (95% CI = 1/391-1/472).

CONCLUSION

Universal 3-step FH screening approach in children enabled detection of most children and their parents in every generation screened at reasonable costs. Opt-out screening strategy might be preferable over opt-in screening strategy.

Inclisiran: How Widely and When Should We Use It?

PURPOSE OF REVIEW

Plasma levels of LDL cholesterol (LDL-C) are causally associated with cardiovascular risk. Reducing LDL-C results in a decreased incidence of cardiovascular events, proportionally to the absolute reduction in LDL-C. The inhibition of proprotein convertase subtilisin kexin 9 (PCSK) is a highly effective and safe approach to reducing LDL-C levels. In this review, we discuss the available data on the efficacy and safety of inclisiran, a siRNA targeting PCSK9 and propose a clinical profile for the patients who can benefit the most from this approach.

RECENT FINDINGS

Inclisiran is a small interfering RNA targeting the mRNA of PCSK9 specifically in the liver, owing to the conjugation with triantennary N-acetylgalactosamine. Randomized clinical trials have shown that inclisiran provides robust and durable reductions of PCSK9 and LDL-C levels, with a dosing schedule of once every 6 months after the initial and 3-month doses. These effects are consistent in different categories of patients, including patients with atherosclerotic cardiovascular disease and/or risk equivalent or patients with heterozygous familial hypercholesterolaemia. Ultimately the administration schedule may improve patients' compliance given also the favourable safety profile of the drug. Completion of ongoing outcome clinical trials will provide information on both the expected clinical benefit and the safety of inclisiran administered for longer.

Single-pill fixed-dose drug combinations to reduce blood pressure: the right pill for the right patient

Arterial hypertension is one of the major causes of cardiovascular morbidity and mortality worldwide. Effective and sustained reduction in blood pressure is essential to reduce individual cardiovascular risk. In daily clinical practice, single-pill fixed-dose combinations of different drug classes are important therapeutic resources that could improve both treatment adherence and cardiovascular risk management by targeting distinct pathophysiological mechanisms. The aim of this practical narrative review is to help physicians choosing the right single-pill fixed-dose combination for the right patient in the daily clinical practice, based on the individual clinical phenotype and cardiovascular risk profile.

Hypercholesterolemia Diagnosis, Treatment Patterns, and 12-Month Target Achievement in Clinical Practice in Germany in Patients with Familial Hypercholesterolemia

Background: Familial hypercholesterolemia (FH) is a highly prevalent disorder and a risk factor for early coronary artery disease. The objective of this registry was to document the clinical characteristics of patients with definite FH in Germany and to document lipid profiles, lipid-lowering therapy, and lipid target achievement during longitudinal follow-up. Methods: HYDRA-FH was a national, prospective, multicenter, non-interventional registry conducted in 35 centers in Germany. Consecutive adult patients with definite FH were included (n = 241). Results: In the cross-sectional analysis (n = 233), lipid-lowering therapy involved statins (82.0%), ezetimibe (31.8%), and PCSK9 antibodies (18.5%); 11.2% of patients were receiving no lipid-lowering drugs. Median lipid levels were: low-density lipoprotein cholesterol (LDL-C) 134 mg/dL (3.5 mmol/L), high-density lipoprotein cholesterol (HDL-C) 48 mg/dL (1.2 mmol/L), triglycerides 160 mg/dL (1.9 mmol/L), total cholesterol 211 mg/dL (5.5 mmol/L). Values were above the normal threshold (150 mg/dL) for LDL-C in 72.9%, total cholesterol in 29.7%, and triglycerides in 45.0% of patients. After the 12-month follow-up (n = 145), only 17.2% had LDL-C < 70 mg/dL, and 20.7% had either LDL-C < 70 mg/dL or a reduction of ≥50% versus baseline. Conclusion: This study provides insight into the clinical characteristics and current treatment status of patients with FH in Germany. Many patients with FH do not achieve recommended lipid levels.

Should We Be Screening for Ischaemic Heart Disease Earlier in Childhood?

Ischaemic heart disease is the most common cause of death in males and the second in the female gender. Yet we often only focus on identification and treatment of this foremost cause of death in adulthood. The review asks the question what form of coronary disease do we encounter in childhood, what predisposing factors give rise to atherosclerosis and what strategies in childhood could we employ to detect and reduce atherosclerosis development in later life.

The Role of Registers in Increasing Knowledge and Improving Management of Children and Adolescents Affected by Familial Hypercholesterolemia: the LIPIGEN Pediatric Group

Pathology registers can be a useful tool to overcome obstacles in the identification and management of familial hypercholesterolemia since childhood. In 2018, the LIPIGEN pediatric group was constituted within the Italian LIPIGEN study to focus on FH subjects under 18 years. This work aimed at discussing its recent progress and early outcomes. Demographic, biochemical, and genetic baseline characteristics were collected, with an in-depth analysis of the genetic defects. The analysis was carried out on 1,602 children and adolescents (mean age at baseline 9.9 ± 4.0 years), and almost the whole cohort underwent the genetic test (93.3%). Overall, the untreated mean value of LDL-C was 220.0 ± 97.2 mg/dl, with an increasing gradient from subjects with a negative (N = 317; mean untreated LDL-C = 159.9 ± 47.7 mg/dl), inconclusive (N = 125; mean untreated LDL-C = 166.4 ± 56.5 mg/dl), or positive (N = 1,053; mean untreated LDL-C = 246.5 ± 102.1 mg/dl) genetic diagnosis of FH. In the latter group, the LDL-C values presented a great variability based on the number and the biological impact of involved causative variants. The LIPIGEN pediatric group represents one of the largest cohorts of children with FH, allowing the deepening of the characterization of their baseline and genetic features, providing the basis for further longitudinal investigations for complete details.

Estimated Yield of Screening for Heterozygous Familial Hypercholesterolemia With and Without Genetic Testing in US Adults

Background Heterozygous familial hypercholesterolemia (FH) is a common genetic disorder causing premature cardiovascular disease. Despite this, there is no national screening program in the United States to identify individuals with FH or likely pathogenic FH genetic variants. Methods and Results The clinical characteristics and FH variant status of 49 738 UK Biobank participants were used to develop a regression model to predict the probability of having any FH variants. The regression model and modified Dutch Lipid Clinic Network criteria were applied to 39 790 adult participants (aged ≥20 years) in the National Health and Nutrition Examination Survey to estimate the yield of FH screening programs using Dutch Lipid Clinic Network clinical criteria alone (excluding genetic variant status), genetic testing alone, or combining clinical criteria with genetic testing. The regression model accurately predicted FH variant status in UK Biobank participants (observed prevalence, 0.27%; predicted, 0.26%; area under the receiver-operator characteristic curve, 0.88). In the National Health and Nutrition Examination Survey, the estimated yield per 1000 individuals screened (95% CI) was 3.7 (3.0-4.6) FH cases with the Dutch Lipid Clinic Network clinical criteria alone, 3.8 (2.7-5.1) cases with genetic testing alone, and 6.6 (5.3-8.0) cases by combining clinical criteria with genetic testing. In young adults aged 20 to 39 years, using clinical criteria alone was estimated to yield 1.3 (95% CI, 0.6-2.5) FH cases per 1000 individuals screened, which was estimated to increase to 4.2 (95% CI, 2.6-6.4) FH cases when combining clinical criteria with genetic testing. Conclusions Screening for FH using a combination of clinical criteria with genetic testing may increase identification and the opportunity for early treatment of individuals with FH.

LDL-C: The Only Causal Risk Factor for ASCVD. Why Is It Still Overlooked and Underestimated?

PURPOSE OF REVIEW

Low-density lipoprotein cholesterol (LDL-C) is the most important causal risk factor for atherosclerotic cardiovascular disease (ASCVD). This article reviews why LDL-C remains overlooked and underestimated despite numerous studies that have proved its role.

RECENT FINDINGS

Recently published EAS/ESC Guidelines for dyslipidemia and EAS Guidelines for prevention set new targets for LDL-C levels in primary and secondary prevention of ASCVD. These guidelines are based on data from large studies and meta-analyzes that have shown that lower LDL-C also means lower cardiovascular event rates. Real-life experience published in registries worldwide has shown us that the guidelines have not been translated to everyday clinical practice, meaning that a significant number of patients are undertreated and have LDL-C levels well above target. Potential reasons for the abovementioned are poor adherence and education of the patient and physician and health care system related factors. Implementation of the latest version of guidelines will require continuous patient and physicians education, as well as a shared decision-making process between physician and patient.

[Genetic diseases of lipid metabolism - Focus familial hypercholesterolemia]

Congenital disorders of lipid metabolism are characterised by LDL-C concentrations > 190 mg/dl (4.9 mM) and/or triglycerides > 200 mg/dl (2.3 mM) in young individuals after having excluded a secondary hyperlipoproteinemia. Further characteristics of this primary hyperlipoproteinemia are elevated lipid values or premature myocardial infarctions within families or xantelasms, arcus lipoides, xanthomas and abdominal pain. This overview summarises our current knowledge of etiology and pathogenesis of primary hyperlipoproteinemia.

Association of dietary patterns and components with atherosclerosis risk biomarkers in familial hypercholesterolemia

PURPOSE OF REVIEW

Familial hypercholesterolemia (FH) is a relatively common genetic disorder associated with elevated atherosclerotic risk. Dietary interventions can modulate processes associated with cardiovascular risk and potentiate the impact of pharmacological lipid-lowering therapies. This review evaluates recent findings of dietary patterns and their components on risk biomarkers in people with FH.

RECENT FINDINGS

Diets lower in saturated fatty acids (SFA) may reduce low-density lipoprotein-cholesterol (LDL-C); however, their effects seem to be modest. A Mediterranean style diet apparently exerts more robust effects on plasma LDL-C, apolipoprotein B and C reactive protein concentrations than one restricted in SFA. Supplementation of plant sterols and stanols reduces LDL-C especially in children with FH. Caloric restricted diets may reduce weight and improve triglyceride levels in individuals with FH and excess body weight.

SUMMARY

Despite the strong impact of genetic variants, dietary patterns mostly low in SFA and especially the Mediterranean diet may influence risk biomarkers in FH. However, most available studies are limited by cross-sectional design, small number of study subjects and short-term follow-ups. Robust interventional studies are necessary to test the impact of dietary patterns in people with FH.

Gene Therapy Targeting PCSK9

The last decades of research in cardiovascular prevention have been characterized by successful bench-to-bedside developments for the treatment of low-density lipoprotein (LDL) hypercholesterolemia. Recent examples include the inhibition of proprotein convertase subtilisin/kexin type 9 (PCSK9) with monoclonal antibodies, small interfering RNA and antisense RNA drugs. The cumulative effects of LDL cholesterol on atherosclerosis make early, potent, and long-term reductions in LDL cholesterol desirable-ideally without the need of regular intake or application of medication and importantly, without side effects. Current reports show durable LDL cholesterol reductions in primates following one single treatment with PCSK9 gene or base editors. Use of the CRISPR/Cas system enables precise genome editing down to single-nucleotide changes. Provided safety and documentation of a reduction in cardiovascular events, this novel technique has the potential to fundamentally change our current concepts of cardiovascular prevention. In this review, the application of the CRISPR/Cas system is explained and the current state of in vivo approaches of PCSK9 editing is presented.

The year in cardiovascular medicine 2021: dyslipidaemia

The past year was an exciting time for clinical lipidology when we learnt more about existing therapies as well as therapies targeting novel pathways discovered through genetic studies. LDL cholesterol remained the main target and a variety of drugs to lower LDL cholesterol through different mechanisms were explored. Emerging evidence on the atherogenity of triglyceride-rich lipoproteins led to renewed interest in lowering them with new treatments. Lp(a) was back in focus with evidence on causality and new targeted therapeutics which dramatically lower Lp(a) levels. We will be able to personalise lipid lowering therapy further with this enriched armamentarium once we have the results of the cardiovascular outcome studies with some of these new agents.

2022 Consensus Statement on the Management of Familial Hypercholesterolemia in Korea

Familial hypercholesterolemia (FH) is the most common monogenic disorder. Due to the marked elevation of cardiovascular risk, the early detection, diagnosis, and proper management of this disorder are critical. Herein, the 2022 Korean guidance on this disease is presented. Clinical features include severely elevated low-density lipoprotein-cholesterol (LDL-C) levels, tendon xanthomas, and premature coronary artery disease. Clinical diagnostic criteria include clinical findings, family history, or pathogenic mutations in the LDLR, APOB, or PCSK9. Proper suspicion of individuals with typical characteristics is essential for screening. Cascade screening is known to be the most efficient diagnostic approach. Early initiation of lipid-lowering therapy and the control of other risk factors are important. The first-line pharmacological treatment is statins, followed by ezetimibe, and PCSK9 inhibitors as required. The ideal treatment targets are 50% reduction and <70 mg/dL or <55 mg/dL (in the presence of vascular disease) of LDL-C, although less strict targets are frequently used. Homozygous FH is characterized by untreated LDL-C >500 mg/dL, xanthoma since childhood, and family history. In children, the diagnosis is made with criteria, including items largely similar to those of adults. In women, lipid-lowering agents need to be discontinued before conception.

PoLA/CFPiP/PCS/PSLD/PSD/PSH guidelines on diagnosis and therapy of lipid disorders in Poland 2021

In Poland there are still nearly 20 million individuals with hypercholesterolaemia, most of them are unaware of their condition; that is also why only ca. 5% of patients with familial hypercholesterolaemia have been diagnosed; that is why other rare cholesterol metabolism disorders are so rarely diagnosed in Poland. Let us hope that these guidelines, being an effect of work of experts representing 6 main scientific societies, as well as the network of PoLA lipid centers being a part of the EAS lipid centers, certification of lipidologists by PoLA, or the growing number of centers for rare diseases, with a network planned by the Ministry of Health, improvements in coordinated care for patients after myocardial infarction (KOS-Zawał), reimbursement of innovative agents, as well as introduction in Poland of an effective primary prevention program, will make improvement in relation to these unmet needs in diagnostics and treatment of lipid disorders possible.

Clinical Features of Familial Hypercholesterolemia in Children and Adults in EAS-FHSC Regional Center for Rare Diseases in Poland

BACKGROUND

Familial hypercholesterolemia (FH) is a genetic autosomal co-dominant metabolic disorder leading to elevated circulating concentrations of low-density lipoprotein cholesterol (LDL-C). Early development of atherosclerotic cardiovascular disease (ASCVD) is common in affected patients. We aimed to evaluate the characteristics and differences in the diagnosis and therapy of FH children and adults. Methods: All consecutive patients who were diagnosed with FH, both phenotypically and with genetic tests, were included in this analysis. All patients are a part of the European Atherosclerosis Society FH-Study Collaboration (FHSC) regional center for rare diseases at the Polish Mother's Memorial Hospital Research Institute (PMMHRI) in Lodz, Poland. Results: Of 103 patients with FH, there were 16 children (15.5%) at mean age of 9 ± 3 years and 87 adults aged 41 ± 16; 59% were female. Children presented higher mean levels of total cholesterol, LDL-C, and high-density lipoprotein cholesterol (HDL-C) measured at the baseline visit (TC 313 vs. 259 mg/dL (8.0 vs. 6.6 mmol/L), p = 0.04; LDL 247 vs. 192 mg/dL (6.3 vs. 4.9 mmol/L), p = 0.02, HDL 53 vs. 48 mg/dL (1.3 vs. 1.2 mmol/L), p = 0.009). Overall, 70% of adult patients and 56% of children were prescribed statins (rosuvastatin or atorvastatin) on admission. Combination therapy (dual or triple) was administered for 24% of adult patients. Furthermore, 13.6% of adult patients and 19% of children reported side effects of statin therapy; most of them complained of muscle pain. Only 50% of adult patients on combination therapy achieved their treatment goals. None of children achieved the treatment goal.

CONCLUSIONS

Despite a younger age of FH diagnosis, children presented with higher mean levels of LDL-C than adults. There are still urgent unmet needs concerning effective lipid-lowering therapy in FH patients, especially the need for greater use of combination therapy, which may allow LDL-C targets to be met in most of the patients.