Familial hypercholesterolaemia in children and adolescents: gaining decades of life by optimizing detection and treatment

Documenting family history in children with hypercholesterolaemia: A lost opportunity

AIM

To determine whether information about a family history of hypercholesterolaemia or early cardiovascular disease was documented by paediatricians in children and adolescents with elevated low-density lipoprotein (LDL)-cholesterol levels.

METHODS

Retrospective chart review of all children with a LDL-cholesterol level ≥95th percentile (3.4 mmol/L) and ≥99th percentile (3.8 mmol/L) at a tertiary paediatric hospital in 2014.

RESULTS

Of 86 children with a LDL-cholesterol level ≥3.4 mmol/L, only 18 (20.9%) had documentation of a family history of hypercholesterolaemia or early cardiovascular disease. In those 18, 13 (72.2%) had a family history of hypercholesterolaemia and 11 (61.1%) a family history of early cardiovascular disease. Increasing the LDL-cholesterol cut-off level to ≥3.8 mmol/L (n = 46) did not improve documentation of a family history (9/46, 19.6%).

CONCLUSIONS

In patients with elevated LDL-cholesterol levels, paediatricians rarely document a positive or negative family history of hypercholesterolaemia or early cardiovascular disease. This represents a lost opportunity to diagnose children and adolescents with familial hypercholesterolaemia.

Familial hypercholesterolemia in childhood and adolescents: A hidden reality

Familial hypercholesterolemia (FH) is the most common genetic disorder in childhood, but in most cases is not detected. High levels of low-density lipoprotein cholesterol are present since the child's birth and this fact will suppose silent development of early atherosclerosis. In cases of homozygous FH, the coronary disease will appear before 20s and in cases of heterozygous FH will occur in middle age. Despite published data, there is not agreement about how and when perform the screening. Familial history of early cardiovascular disease plus presence of hypercholesterolemia in parents is crucial for detection and diagnosis. Actually, it is topic of discussion that it is necessary to achieve therapeutic goals from an early age to improve prognosis. Lifestyle changes are the first line therapy. Statins are the lipid-lowering drugs of choice but the optimal age to start therapy it is still controversial. In this article, current recommendations of expert consensus guidelines about the management and new line therapies of child and adolescents are reviewed.

Progress in the care of familial hypercholesterolaemia: 2016

Familial hypercholesterolaemia (FH) is the most common autosomal dominant condition, with a prevalence of between one in 200 and one in 350 people in the general population. Untreated FH is associated with premature atherosclerotic cardiovascular disease (CVD). The prevalence of homozygous or compound heterozygous FH is now considered to be about one in 300 000 people. Treating children with FH reduces progression of atherosclerotic CVD and future CVD events. Most individuals with FH are undiagnosed, which together with the recent frequency data in the population and in individuals with premature coronary disease creates a public health challenge and mandates a key role for primary care. Childhood is the optimal period for detecting FH, since low-density lipoprotein cholesterol (LDL-c) concentrations better differentiate affected from unaffected individuals. In an Australian community setting, over 70% of adults with an LDL-c level ≥ 6.5 mmol/L have clinical FH; of these, 30% have a detectable mutation. The community laboratory has an important role in identifying FH, with interpretive comments leading to additional reductions in LDL-c concentrations, and a phone call from the pathologist to the general practitioner improving detection of cases. Cascade screening using DNA testing is cost-effective and acceptable to screenees. Next generation genetic sequencing may differentiate people with polygenic hypercholesterolaemia alone from those with FH. Smoking, hypertension, elevated lipoprotein(a) levels, chronic kidney disease and diabetes are additional atherosclerotic CVD risk factors in FH. Equations for assessing absolute risk of CVD in primary prevention underestimate risk in FH. The adult LDL-c goal is a greater than 50% reduction in LDL-c levels, followed by a target of < 2.5 mmol/L, or < 1.8 mmol/L for individuals with CVD or other CVD risk factors. Proprotein convertase subtilisin/kexin type 9 inhibitors significantly reduce LDL-c and lipoprotein(a) levels in people with FH. Registries are essential for improving the care of people with FH.

Analysis of Children and Adolescents with Familial Hypercholesterolemia

OBJECTIVE

To evaluate the effectiveness of criteria based on child-parent assessment in predicting familial hypercholesterolemia (FH)-causative mutations in unselected children with hypercholesterolemia.

STUDY DESIGN

LDLR, APOB, and PCSK9 genes were sequenced in 78 children and adolescents (mean age 8.4 ± 3.7 years) with clinically diagnosed FH. The presence of polygenic hypercholesterolemia was further evaluated by genotyping 6 low-density lipoprotein cholesterol (LDL-C)-raising single-nucleotide polymorphisms.

RESULTS

Thirty-nine children (50.0%) were found to carry LDLR mutant alleles but none with APOB or PCSK9 mutant alleles. Overall, 27 different LDLR mutations were identified, and 2 were novel. Children carrying mutations showed higher LDL-C (215.2 ± 52.7 mg/dL vs 181.0 ± 44.6 mg/dL, P <.001) and apolipoprotein B levels (131.6 ± 38.3 mg/dL vs 100.3 ± 30.0 mg/dL, P <.004), compared with noncarriers. A LDL-C of ~190 mg/dL was the optimal value to discriminate children with and without LDLR mutations. When different diagnostic criteria were compared, those proposed by the European Atherosclerosis Society showed a reasonable balance between sensitivity and specificity in the identification of LDLR mutations. In children without mutation, the FH phenotype was not caused by the aggregation of LDL-C raising single-nucleotide polymorphisms.

CONCLUSIONS

In unselected children with hypercholesterolemia, LDL-C levels >190 mg/dL and a positive family history of hypercholesterolemia appeared to be the most reliable criteria for detecting FH. As 50% of children with suspected FH did not carry FH-causing mutations, genetic testing should be considered.

Genotype-guided diagnosis in familial hypercholesterolemia: clinical management and concerns

PURPOSE OF REVIEW

In this review, we examine benefits and concerns associated with genetic testing in the clinical management of familial hypercholesterolemia (FH).

RECENT FINDINGS

Application of next-generation sequencing and other advances provide improved yield of causal mutations compared with older methods and help disclose underlying pathophysiology in many instances. Concerns regarding clinical application of genetic testing remain.

SUMMARY

More widespread application of genetic testing for FH in the USA may be forthcoming. When a genetic cause of FH can be identified or is known for the family, test results can provide more accurate individual diagnosis of FH, clarification of underlying pathophysiology, and greater clinical insight. However, several concerns persist, particularly cost to FH patients, potential discrimination, and inappropriate denial of clinically indicated therapies for patients without definitive genetic testing results.

Time to improve statin prescription guidelines in low-risk patients?

Background

The challenge of the primary prevention of cardiovascular disease (CVD) is to identify patients who would benefit from treatment with statins. Statins are currently prescribed to many patients, even those at a low 10-year risk of CVD. These latter patients may not be eligible for statins according to current guidelines.

Design

This study investigated the prescription of guideline-consistent (according to guidelines) and guideline-inconsistent (not according to guidelines) lipid-lowering treatment in primary prevention in a large contemporary Dutch cohort study (Lifelines).

Methods

Lifelines is a large cohort study from the Netherlands. Participants were recruited between 2006 and 2013. They completed questionnaires and underwent a physical examination. Participants with previous CVD were excluded. Statins and ezetimibe were grouped as statin treatment. The Dutch guideline on cardiovascular management was used to assess eligibility for statins.

Results

Of 147,785 participants, 7092 (4.8%) reported statin treatment. In 4667 (66%) participants, statin treatment was inconsistent with the Dutch guideline. A total of 78% of these participants had a low 10-year predicted CVD risk. Multivariable logistic regression analysis showed that female sex and smoking were strongly associated with guideline-inconsistent treatment. Interestingly, 65% of the these participants had low-density lipoprotein cholesterol levels above the 95^th percentile, adjusted for age and sex, two or more major risk factors of CVD or a positive family history of premature CVD. Therefore treatment might be reasonable.

Conclusions

There is a large inconsistency between guideline recommendations and the prescription of statins in clinical practice in the Netherlands. This is especially true for patients with low CVD risk. Many of these patients probably had risk-increasing circumstances justifying treatment.

Update on Familial Hypercholesterolemia: Diagnosis, Cardiovascular Risk, and Novel Therapeutics

In recent studies, the reported prevalence of heterozygous familial hypercholesterolemia (FH) has been higher than in previous reports. Although cascade genetic screening is a good option for efficient identification of affected patients, diagnosis using only clinical criteria is more common in real clinical practice. Cardiovascular risk is much higher in FH patients due to longstanding low density lipoprotein cholesterol (LDL-C) burden and is also influenced by other risk factors. Although guidelines emphasize aggressive LDL-C reduction, the majority of patients cannot reach the LDL-C goal by conventional pharmacotherapy. Novel therapeutics such as proprotein convertase subtilisin/kexin type 9 inhibitors have shown strong lipid lowering efficacy and are expected to improve treatment results in FH patients.

Detecting familial hypercholesterolemia: The Jack and the Beanstalk principle

We report the case of an 8-year-old girl who was fortuitously diagnosed with familial hypercholesterolemia (FH) while being investigated for obesity. She had a fasting total cholesterol of 11.8 mmol/L and a low-density lipoprotein cholesterol level of 10.3 mmol/L. Her mother and maternal grandmother both had a history of hypercholesterolemia and had developed extensive xanthelasma palpebrarum from early adult life. Reverse cascade testing of first-degree and second-degree relatives diagnosed a further 6 individuals with FH within the family. We discuss the benefits of diagnosing FH in childhood, for the individual and the wider family network ("the beanstalk") and present the rationale for implementing a universal screening program for FH in childhood.

Atypical Presentation and Treatment Response in a Child with Familial Hypercholesterolemia Having a Novel LDLR Mutation

Familial hypercholesterolemia (FH) is an autosomal codominantly inherited disease. The severity of clinical presentation depends on the zygosity of the mutations in the LDLR, APOB, or PCSK9 genes. The homozygous form (HoFH) is associated with high mortality rate by third decade of life, while individuals with HeFH begin to suffer from premature cardiovascular disease in fourth or fifth decade of life. Statin drugs have helped to improve the biochemical profile and life expectancy in HeFH, while they are only minimally effective in HoFH. LDL apheresis remains an effective treatment option in HoFH, though limited by its availability and affordability issues. We present the case that highlights a few novel aspects of clinical and genetic heterogeneity in FH, wherein a child presented with features of both HeFH and HoFH. His clinical picture was that of HoFH; however he responded well clinically and biochemically to pharmacologic treatment only. DNA sequencing showed a novel heterozygous rare splicing variant in the LDLR gene in addition to a relatively high polygenic trait score comprised of LDL-C raising alleles from common polymorphic sites. Interestingly his normolipemic mother showed the same heterozygous mutation. Thus this novel splicing variant in LDLR showed nonclassical co-segregation with the disease phenotype and was associated with a high polygenic trait score comprised of common LDL-C raising polymorphic alleles in the affected proband. Thus it indicates the phenotypic heterogeneity of FH and suggests that secondary causes, such as polygenic factors and possibly as yet undetermined genetic or environmental factors, can exacerbate the metabolic phenotype in an individual who is genotypically heterozygous for FH.

Vallejo-Vaz AJ, Akram A, Kondapally Seshasai SR, Cole D, Watts GF, Hovingh GK, Kastelein JJP, Mata P, Raal FJ, Santos RD, Soran H, Freiberger T, Abifadel M, Aguilar-Salinas CA, Alnouri F, Alonso R, Al-Rasadi K, Banach M, Bogsrud MP, Bourbon M, Bruckert E, Car J, Ceska R, Corral P, Descamps O, Dieplinger H, Do CT, Durst R, Ezhov MV, Fras Z, Gaita D, Gaspar IM, Genest J, Harada-Shiba M, Jiang L, Kayikcioglu M, Lam CSP, Latkovskis G, Laufs U, Liberopoulos E, Lin J, Lin N, Maher V, Majano N, Marais AD, März W, Mirrakhimov E, Miserez AR, Mitchenko O, Nawawi H, Nilsson L, Nordestgaard BG, Paragh G, Petrulioniene Z, Pojskic B, Reiner Ž, Sahebkar A, Santos LE, Schunkert H, Shehab A, Slimane MN, Stoll M, Su TC, Susekov A, Tilney M, Tomlinson B, Tselepis AD, Vohnout B, Widén E, Yamashita S, Catapano AL, Ray KK. Pooling and expanding registries of familial hypercholesterolaemia to assess gaps in care and improve disease management and outcomes: Rationale and design of the global EAS Familial Hypercholesterolaemia Studies Collaboration

BACKGROUND

The potential for global collaborations to better inform public health policy regarding major non-communicable diseases has been successfully demonstrated by several large-scale international consortia. However, the true public health impact of familial hypercholesterolaemia (FH), a common genetic disorder associated with premature cardiovascular disease, is yet to be reliably ascertained using similar approaches. The European Atherosclerosis Society FH Studies Collaboration (EAS FHSC) is a new initiative of international stakeholders which will help establish a global FH registry to generate large-scale, robust data on the burden of FH worldwide.

METHODS

The EAS FHSC will maximise the potential exploitation of currently available and future FH data (retrospective and prospective) by bringing together regional/national/international data sources with access to individuals with a clinical and/or genetic diagnosis of heterozygous or homozygous FH. A novel bespoke electronic platform and FH Data Warehouse will be developed to allow secure data sharing, validation, cleaning, pooling, harmonisation and analysis irrespective of the source or format. Standard statistical procedures will allow us to investigate cross-sectional associations, patterns of real-world practice, trends over time, and analyse risk and outcomes (e.g. cardiovascular outcomes, all-cause death), accounting for potential confounders and subgroup effects.

CONCLUSIONS

The EAS FHSC represents an excellent opportunity to integrate individual efforts across the world to tackle the global burden of FH. The information garnered from the registry will help reduce gaps in knowledge, inform best practices, assist in clinical trials design, support clinical guidelines and policies development, and ultimately improve the care of FH patients.

Homozygous Familial Hypercholesterolemia in Spain

Background—

Homozygous familial hypercholesterolemia (HoFH) is a rare disease characterized by elevated plasma levels of low-density lipoprotein cholesterol (LDL-C) and extremely high risk of premature atherosclerotic cardiovascular disease. HoFH is caused by mutations in several genes, including LDL receptor ( LDLR ), apolipoprotein B ( APOB ), proprotein convertase subtilisin/kexin type 9 ( PCSK9 ), and LDL protein receptor adaptor 1 ( LDLRAP1 ). No epidemiological studies have assessed HoFH prevalence or the clinical and molecular characteristics of this condition. Here, we aimed to characterize HoFH in Spain.

Methods and Results—

Data were collected from the Spanish Dyslipidemia Registry of the Spanish Atherosclerosis Society and from all molecular diagnoses performed for familial hypercholesterolemia in Spain between 1996 and 2015 (n=16 751). Clinical data included baseline lipid levels and atherosclerotic cardiovascular disease events. A total of 97 subjects were identified as having HoFH—of whom, 47 were true homozygous (1 for APOB , 5 for LDLRAP1 , and 41 for LDLR ), 45 compound heterozygous for LDLR , 3 double heterozygous for LDLR and PSCK9 , and 2 double heterozygous for LDLR and APOB . No PSCK9 homozygous cases were identified. Two variants in LDLR were identified in 4.8% of the molecular studies. Over 50% of patients did not meet the classical HoFH diagnosis criteria. The estimated HoFH prevalence was 1:450 000. Compared with compound heterozygous cases, true homozygous cases showed more aggressive phenotypes with higher LDL-C and more atherosclerotic cardiovascular disease events.

Conclusions—

HoFH frequency in Spain was higher than expected. Clinical criteria would underestimate the actual prevalence of individuals with genetic HoFH, highlighting the importance of genetic analysis to improve familial hypercholesterolemia diagnosis accuracy.

Lipoprotein(a) in postmenopausal women: assessment of cardiovascular risk and therapeutic options

INTRODUCTION

Lipoprotein(a) [Lp(a)], a low-density lipoprotein (LDL)-like particle, has been independently associated with increased cardiovascular disease (CVD) risk in various populations, such as postmenopausal women. The purpose of this narrative review is to present current data on the role of Lp(a) in augmenting CVD risk in postmenopausal women and focus on the available therapeutic strategies.

METHODS

PubMed was searched for English language publications until November 2015 under the following terms: "therapy" OR "treatment" AND ["lipoprotein (a)" OR "Lp(a)"] AND ("postmenopausal women" OR "menopausal women" OR "menopause").

RESULTS

Only hormone replacement therapy (mainly oral estrogens) and tibolone have been specifically studied in postmenopausal women and can reduce Lp(a) concentrations by up to 44%, although evidence indicating a concomitant reduction in CVD risk associated with Lp(a) is lacking. As alternative treatments for women who cannot, or will not, take hormonal therapies, niacin and the upcoming proprotein convertase subtilisin / kexin type 9 (PCSK-9) inhibitors are effective in reducing Lp(a) concentrations by up to 30%. Statins have minimal or no effect on Lp(a). However, data for these and other promising Lp(a)-lowering therapies including mipomersen, lomitapide, cholesterol-ester-transfer protein inhibitors and eprotirome are derived from studies in the general, mainly high CVD risk, population, and include only subpopulations of postmenopausal women.

CONCLUSIONS

Past, present and emerging therapies can reduce Lp(a) concentrations to a varying extent. Overall, it remains to be proven whether the aforementioned reductions in Lp(a) by these therapeutic options are translated into CVD risk reduction in postmenopausal women.

Challenges in the health economics of familial hypercholesterolemia

PURPOSE OF REVIEW

Implementation of effective interventions often requires evidence regarding value, that is, whether they are worth what we pay for them. This review explores recent evidence concerning cost-effectiveness in familial hypercholesterolemia, and discusses the cause of, and likelihood of solutions to, the paucity of such evidence.

RECENT FINDINGS

Cost-effectiveness analysis in familial hypercholesterolemia has been limited almost exclusively to adult populations. However, there is growing evidence that childhood intervention offers substantial benefit in terms of downstream health gains. Statin therapy in adults has been demonstrated to be cost-effective, but the range of novel agents that might be used will require de novo economic evaluation alongside exploration of their effect and safety profile.

SUMMARY

The familial hypercholesterolemia field has limited evidence regarding cost-effectiveness, which limits optimum allocation of resources. Economic evaluations are necessary to appraise new agents and optimal timing of management approaches. Evaluations often have substantial data demands; consequentially, their applicability to medical decision-making or policy will be partly determined by the availability of data, particularly those providing information about the long-term trajectory of health benefit from familial hypercholesterolemia treatment.

Attainment of LDL Cholesterol Treatment Goals in Children and Adolescents With Familial Hypercholesterolemia. The SAFEHEART Follow-up Registry

INTRODUCTION AND OBJECTIVES

Little is known about the characteristics of persons with familial hypercholesterolemia (FH) younger than 18 years, the lipid-lowering therapy used in these patients, and the lipid goals reached in real life. Our aim was to evaluate the achievement of low-density lipoprotein cholesterol (LDL-C) treatment goals in FH patients younger than 18 years enrolled in a large national registry.

METHODS

We analyzed patients younger than 18 years enrolled in a large ongoing registry of molecularly-defined patients with FH in Spain. The attainment of guideline-recommended plasma LDL-C goals at entry and follow-up was analyzed in relation to the use of lipid-lowering therapy.

RESULTS

We enrolled 392 individuals younger than 18 years. Of these, 217 were molecularly-diagnosed FH patients and had a complete follow-up. The median follow-up time was 4.69 years (interquartile range, 2.48-6.38 years), 68.2% of FH patients were on statins, and 41.5% patients had LDL-C < 130mg/dL. Statin use was the only predictor of LDL-C goal attainment.

CONCLUSIONS

This study shows that a high proportion of FH patients younger than 18 years have high LDL-C levels and fail to achieve recommended LDL-C targets. Statin use was the only independent predictor of LDL-C goal achievement. No safety concerns were detected during follow-up. These results indicate that many FH patients are not adequately controlled and that there is still room for treatment improvement.

Issues and Challenges in Diagnostic Sequencing for Inherited Cardiac Conditions

BACKGROUND

Inherited cardiac conditions are a relatively common group of Mendelian diseases associated with ill health and death, often in the young. Research into the genetic causes of these conditions has enabled confirmatory and predictive diagnostic sequencing to become an integral part of the clinical management of inherited cardiomyopathies, arrhythmias, aortopathies, and dyslipidemias.

CONTENT

Currently, the principle benefit of clinical genetic testing is the cascade screening of family members of patients with a pathogenic variant, enabling targeted follow up of presymptomatic genotype-positive individuals and discharge of genotype-negative individuals to health. For the affected proband, diagnostic sequencing can also be useful in discriminating inherited disease from alternative diagnoses, directing treatment, and for molecular autopsy in cases of sudden unexplained death. Advances in sequencing technology have expanded testing panels for inherited cardiac conditions and driven down costs, further improving the cost-effectiveness of genetic testing. However, this expanded testing requires great rigor in the identification of pathogenic variants, with domain-specific knowledge required for variant interpretation.

SUMMARY

Diagnostic sequencing has the potential to become an integral part of the clinical management of patients with inherited cardiac conditions. However, to move beyond just confirmatory and predictive testing, a much greater understanding is needed of the genetic basis of these conditions, the role of the environment, and the underlying disease mechanisms. With this additional information it is likely that genetic testing will increasingly be used for stratified and preventative strategies in the era of genomic medicine.

Development of proprotein convertase subtilisin/kexin type 9 inhibitors and the clinical potential of monoclonal antibodies in the management of lipid disorders

The aim of this manuscript is to review available data to evaluate the present status of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors in the treatment of hypercholesterolemia. Relevant literature since 2003 is reviewed. The effectiveness of PCSK9 inhibitors in lowering low-density lipoprotein cholesterol and other atherogenic lipid fractions was studied in various Phase 2 and Phase 3 trials of Alirocumab, Evolocumab, and Bococizumab. The results of published long-term ODYSSEY and OSLER studies are summarized. There have been three excellent meta-analysis studies on PCSK9 inhibitors which are outlined. The complex problem of cost-effectiveness was carefully evaluated by the Institute for Clinical and Economic Review (ICER). The draft report (ICER-2015) is summarized herewith. The cardiovascular outcome trials with Evolocumab (FOURIER), Alirocumab (ODYSSEY OUTCOME) and Bococizumab (SPIRE-1 and SPIRE-2) are the ongoing clinical trials, and their results are expected in 2017-2018. The search for new cost-effective analogs of PCSK9 inhibitors is ongoing.

Statins in the Management of Pediatric Dyslipidemia

Hypercholesterolemia is a major concern in the USA, with studies identifying children as young as 2years old with early-stage atherosclerosis. Genetics play a major role in the dyslipidemia of children, but other factors, such as diet and lack of physical activity, confound the problem. Familial hypercholesterolemia (FH) is a genetic condition that causes lifelong elevations in low-density lipoprotein cholesterol (LDL-C). The heterozygous form of the disease affects around 1 in 200 people, and the homozygous form of the disease affects around 1 in 160,000-300,000 people. Early identification and appropriate management of patients with FH are essential to reduce cardiovascular disease morbidity and mortality. Consequently, US dyslipidemia guidelines recommend routine screening of all children aged 9-11years, and that LDL-C levels should be <110mg/dL in children and adolescents. The primary management strategy in all children with dyslipidemia is diet and lifestyle; a healthy diet (including fruits, vegetables, fish, and whole grains) and increased physical activity should be encouraged. Most patients with FH will also require pharmacotherapy to reduce LDL-C levels to ≤130mg/dL. Statins are recommended as first-line therapy due to their proven efficacy in reducing LDL-C and improving other lipid parameters in children. They have also been shown to have a positive effect on atherosclerosis. Safety is of particular concern with children; however, studies have so far shown that the side-effect profile of statins in children is similar to that in adults. Despite improvements in disease management, FH remains underdiagnosed and undertreated, highlighting the need for greater awareness and understanding.

Diverse etiology of hyperlipidemia among hospitalized children in Western region of Saudi Arabia

OBJECTIVES

To determine the various etiologies of primary and secondary hyperlipidemia among children visiting the pediatric endocrine clinic. Methods: This is a retrospective, cross-sectional, cohort study conducted at King Abdulaziz University Hospital (KAUH), Jeddah, Kingdom of Saudi Arabia from January 2010 to 2015 that included 253 children aged from birth to 12 years old. Data were obtained by reviewing medical reports of patients who presented with hyperlipidemia to the clinic, and their laboratory investigation results using KAUH electronic "Phoenix" system.  Results: Of the 253 children who were reviewed, those who have shown to have abnormal lipid metabolism with nephrotic syndrome were 35.6%, diabetes mellitus 17.8%, primary/idiopathic hyperlipidemia 19.4%, hypothyroidism 7.1%, obesity 4.3%, metabolic syndrome 2.8%, chronic liver disease 2% and chronic renal failure 1.2%. The body mass index relative to gender and age in this group of children showed that 23.2% were underweight, 38.4% were normal weight, 8.9% were overweight, and 29.5% were obese.  Conclusion: The highest prevalence of hyperlipidemia was in nephrotic syndrome, followed by primary/idiopathic hyperlipidemia and diabetes mellitus.

Defining severe familial hypercholesterolaemia and the implications for clinical management: a consensus statement from the International Atherosclerosis Society Severe Familial Hypercholesterolemia Panel

Familial hypercholesterolaemia is common in individuals who had a myocardial infarction at a young age. As many as one in 200 people could have heterozygous familial hypercholesterolaemia, and up to one in 300 000 individuals could be homozygous. The phenotypes of heterozygous and homozygous familial hypercholesterolaemia overlap considerably; the response to treatment is also heterogeneous. In this Review, we aim to define a phenotype for severe familial hypercholesterolaemia and identify people at highest risk for cardiovascular disease, based on the concentration of LDL cholesterol in blood and individuals' responsiveness to conventional lipid-lowering treatment. We assess the importance of molecular characterisation and define the role of other cardiovascular risk factors and advanced subclinical coronary atherosclerosis in risk stratification. Individuals with severe familial hypercholesterolaemia might benefit in particular from early and more aggressive cholesterol-lowering treatment (eg, with PCSK9 inhibitors). In addition to better tailored therapy, more precise characterisation of individuals with severe familial hypercholesterolaemia could improve resource use.

Lipoprotein (a) as a cause of cardiovascular disease: insights from epidemiology, genetics, and biology

Human epidemiologic and genetic evidence using the Mendelian randomization approach in large-scale studies now strongly supports that elevated lipoprotein (a) [Lp(a)] is a causal risk factor for cardiovascular disease, that is, for myocardial infarction, atherosclerotic stenosis, and aortic valve stenosis. The Mendelian randomization approach used to infer causality is generally not affected by confounding and reverse causation, the major problems of observational epidemiology. This approach is particularly valuable to study causality of Lp(a), as single genetic variants exist that explain 27-28% of all variation in plasma Lp(a). The most important genetic variant likely is the kringle IV type 2 (KIV-2) copy number variant, as the apo(a) product of this variant influences fibrinolysis and thereby thrombosis, as opposed to the Lp(a) particle per se. We speculate that the physiological role of KIV-2 in Lp(a) could be through wound healing during childbirth, infections, and injury, a role that, in addition, could lead to more blood clots promoting stenosis of arteries and the aortic valve, and myocardial infarction. Randomized placebo-controlled trials of Lp(a) reduction in individuals with very high concentrations to reduce cardiovascular disease are awaited. Recent genetic evidence documents elevated Lp(a) as a cause of myocardial infarction, atherosclerotic stenosis, and aortic valve stenosis.

Cascade Screening for Familial Hypercholesterolemia: PCR Methods with Melting-Curve Genotyping for the Targeted Molecular Detection of Apolipoprotein B and LDL Receptor Gene Mutations to Identify Affected Relatives

BACKGROUND

A key objective of the UK National Institute for Health and Care Excellence (NICE) pathway for diagnosis of familial hypercholesterolemia (FH) is the identification of affected relatives of index cases through cascade screening. At present, there is no systematic appraisal of available methodological options to identify the appropriate diagnostic testing protocol that would allow cost-effective cascade genetic screening. The majority of FH-causing mutations identified in the LDL receptor (LDLR) or apolipoprotein B (APOB) genes are single-nucleotide changes. This pattern of mutations suggests that PCR methods using melting curve-based genotyping might offer a convenient methodological approach for screening relatives.

METHODS

We developed and validated one-tube PCR methods for the mutations APOB c.10580G>A (p.Arg3527Gln), LDLR c.1474G>A (p.Asp492Asn), and c.2054C>T (p.Pro685Leu) and 3 novel LDLR mutations identified in the Coventry and Warwickshire population: LDLR c.1567G>C (p.Val523Leu), c.487dupC (p.Gln163Profs17), and c.647G>C (p.Cys216Ser).

RESULTS

These methods successfully amplified target sequence from genomic DNA extracted from either peripheral blood or saliva. They also demonstrated acceptable analytical performance characteristics (specificity of amplification, repeatability, and reproducibility) over a wide range of DNA concentrations and purity. This approach was used for cascade testing of relatives of index FH cases with confirmed mutations and identified family members with high plasma LDL cholesterol as heterozygous for disruptive alleles.

CONCLUSIONS

Our study generates proof-of-concept evidence of methods suitable for detecting single nucleotide substitutions and insertions that can deliver reliable, easy, low-cost, and rapid family screening of FH patients and can be adopted by nonspecialist molecular diagnostic laboratories.

Clinical characterization and mutation spectrum of German patients with familial hypercholesterolemia

BACKGROUND AND AIMS

Autosomal-dominant familial hypercholesterolemia (FH) is characterized by elevated plasma levels of low-density lipoprotein cholesterol (LDL-C) and a dramatically increased risk to develop cardiovascular disease (CVD). Mutations in three major genes have been associated with FH: the LDL receptor gene (LDLR), the apolipoprotein B gene (APOB), and the proprotein convertase subtilisin/kexin 9 gene (PCSK9). Here we investigated the frequency and the spectrum of FH causing mutations in Germany.

METHODS

We screened 206 hypercholesterolemic patients, of whom 192 were apparently unrelated, for mutations in the coding region of the genes LDLR, PCSK9 and the APOB [c.10580G > A (p.Arg3527Gln)]. We also categorized the patients according to the Dutch Lipid Clinic Network Criteria (DLCNC) in order to allow a comparison between the mutations identified and the clinical phenotypes observed. Including data from previous studies on German FH patients enabled us to analyse data from 479 individuals.

RESULTS

Ninety-eight FH causing variants were found in 92 patients (nine in related patients and 6 patients with two variants and likely two affected alleles), of which 90 were located in the LDLR gene and eight mutations were identified in the APOB gene (c.10580G > A). No mutation was found in the PCSK9 gene. While 48 of the LDLR mutations were previously described as disease causing, we found 9 new LDLR variants which were rated as "pathogenic" or "likely pathogenic" based on the predicted effect on the corresponding protein. The proportions of different types of LDLR mutations and their localization within the gene was similar in the group of patients screened for mutations here and in the combined analysis of 479 patients (current study/cases from the literature) and also to other studies on the LDLR mutation spectrum, with about half of the variants being of the missense type and clustering of mutations in exons 4, 5 and 9. The mutation detection rate in the 35 definite and 45 probable FH patients (according to DLCNC) was 77.1% and 68.9%, respectively. The data show a similar discriminatory power between the DLCNC score (AUC = 0.789 (95% CI 0.721-0,857)) and baseline LDL-C levels (AUC = 0.799 (95% CI = 0.732-0.866)).

CONCLUSIONS

This study further substantiates the mutation spectrum for FH in German patients and confirms the clinical and genetic heterogeneity of the disease.

Effects of Liver Transplantation on Lipids and Cardiovascular Disease in Children With Homozygous Familial Hypercholesterolemia

Homozygous familial hypercholesterolemia (HoFH) is a rare, inherited, life-threatening, metabolic disorder of low-density lipoprotein (LDL) receptor function characterized by elevated serum LDL cholesterol (LDL-C) and rapidly progressive atherosclerotic cardiovascular disease (ACVD). Since LDL receptors are predominantly found on hepatocytes, orthotopic liver transplantation (OLT) has emerged as a viable intervention for HoFH because LDL receptor activity is restored. This study assessed the effects of OLT on ACVD and ACVD risk factors in pediatric patients with HoFH. We analyzed lipids, lipoproteins, body mass index, glucose, blood pressure, and cardiovascular imaging in 8 pediatric patients who underwent OLT for HoFH. Total serum cholesterol, LDL-C, lipoprotein (a), and apolipoprotein B/apolipoprotein A1 ratio decreased to normal values in all subjects (p values <0.001) at 1 month after OLT and were maintained for the length of follow-up (2 to 6 years). There were few complications related to surgery or immunosuppressive therapy. Two patients developed mild hypertension. In the first 4 subjects monitored for 4 to 6 years after OLT, coronary artery disease did not develop or progress except in 1 minor artery in 1 subject and actually regressed in 2 subjects with >50% stenosis. However, aortic valve stenosis progressed in 2 of 4 subjects. In conclusion, OLT is an effective therapeutic option for patients with HoFH with coronary artery disease and persistently elevated serum LDL-C despite maximum medical therapy. Aortic valvular disease may progress. Long-term data are needed to evaluate the true risk-benefit ratio of this surgical approach.

Progress in the care of common inherited atherogenic disorders of apolipoprotein B metabolism

Familial hypercholesterolaemia, familial combined hyperlipidaemia (FCH) and elevated lipoprotein(a) are common, inherited disorders of apolipoprotein B metabolism that markedly accelerate the onset of atherosclerotic cardiovascular disease (ASCVD). These disorders are frequently encountered in clinical lipidology and need to be accurately identified and treated in both index patients and their family members, to prevent the development of premature ASCVD. The optimal screening strategies depend on the patterns of heritability for each condition. Established therapies are widely used along with lifestyle interventions to regulate levels of circulating lipoproteins. New therapeutic strategies are becoming available, and could supplement traditional approaches in the most severe cases, but their long-term cost-effectiveness and safety have yet to be confirmed. We review contemporary developments in the understanding, detection and care of these highly atherogenic disorders of apolipoprotein B metabolism.

Identifying familial hypercholesterolemia in acute coronary syndrome

PURPOSE OF REVIEW

Familial hypercholesterolemia is a frequent genetic disorder characterized by elevated LDL-cholestrol and premature coronary heart disease. Familial hypercholesterolemia remains largely underdiagnosed in the general population and for many patients the initial clinical manifestation is acute coronary syndromes (ACS). Furthermore, many missed diagnosis of familial hypercholesterolemia can also occur during hospitalization for ACS. In this review, we aim to discuss the identification and prognosis of familial hypercholesterolemia after hospitalization for ACS.

RECENT FINDINGS

The prevalence of familial hypercholesterolemia was about 10 times higher among patients hospitalized for ACS compared with the general population. Although 70% of patients with familial hypercholesterolemia were discharged with high-intensity statins, and 65% attended cardiac rehabilitation, less than 5% reached the recommended LDL-cholesterol target less than 1.8 mmol/l 1 year after ACS. Furthermore, patients with familial hypercholesterolemia and ACS were at high-risk of recurrence of cardiovascular events after discharge.

SUMMARY

A systematic screening strategy to identify patients with familial hypercholesterolemia at the time ACS is required to maximize secondary prevention and improve lipid management. It is expected that a substantial number of familial hypercholesterolemia patients would benefit from more effective lipid-lowering drugs after ACS, in addition to statins.

Advanced Imaging and Diagnostic Methods in the Assessment of Suspected Ischemic Heart Disease in Women

Although differences diminish with age, outcomes are overall worse for women compared to men who present with suspected acute coronary syndrome. The reasons for this discrepancy are multifactorial, including sex-related differences in atherosclerosis biology and fluid dynamics, as well as a premature conclusion by providers that chest pain must be noncardiac in the absence of obstructive coronary artery disease. In this review of existing literature, we explore the diverse differential diagnosis in this unique set of patients. Especially in women with persistent symptoms, absence of occlusive disease should prompt consideration for subangiographic plaque disruption, epicardial or microvascular endothelial dysfunction, transient neurohormonal imbalance predisposing to Takotsubo cardiomyopathy or spontaneous coronary artery dissection, underlying systemic inflammatory conditions, thromboembolic disease, myocarditis, and sequelae of congenital heart disease. As always, a thorough history and attentive physical exam will help guide further work-up, which in many cases may warrant noninvasive imaging, such as contrast-enhanced echocardiography, cardiac magnetic resonance imaging, or positron emission tomography, with their respective means of measuring myocardial perfusion and myocardial tissue pathology. Lastly, intracoronary imaging such as intravascular ultrasound and optical coherence tomography and invasive diagnostic methods such as coronary reactivity testing continue to add to our understanding that what appear to be atypical presentations of ischemic heart disease in women may in fact be typical presentations of pathologic cousin entities that remain incompletely defined.

Dietary counseling is associated with an improved lipid profile in children with familial hypercholesterolemia

BACKGROUND AND AIMS

Familial hypercholesterolemia (FH) is a genetic disorder characterized by elevated levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C). Guidelines recommend cholesterol-lowering medication from 8 to 10 years of age and dietary recommendations. Little is known about the diet of FH children and the effect of dietary counseling. The aim of the study was to describe the diet of FH children with respect to fat quality, and to investigate if dietary counseling improved lipid profile.

METHODS

Fifty-four FH children (5-18 years) were included in the study and dietary intake was recorded with a pre-coded food diary for four days. Information about plasma lipid levels was obtained.

RESULTS

Median intake of total fat, monounsaturated fat, polyunsaturated fat (PUFA) and saturated fat (SFA) was 30.8, 10.4, 5.9 and 12.0 E %, respectively. Among non-statin treated FH children, SFA intake was significantly correlated with TC, LDL-C and apolipoprotein (apo) B (rsp = 0.55; p = 0.004, rsp = 0.46; p = 0.02, and rsp = 0.45; p = 0.02, respectively), and PUFA/SFA ratio significantly inversely correlated with TC (rsp = -0.42; p = 0.03). Compared to the first visit, non-statin and non-plant sterol treated FH children (n = 10) had significantly reduced levels of TC (p < 0.01), LDL-C (p = 0.01), high-density lipoprotein cholesterol (p = 0.02), apo B (p = 0.05) and apo A-1 (p = 0.02) levels at a later visit.

CONCLUSIONS

FH children had a higher intake of SFA than recommended and the SFA intake was positively correlated with plasma TC, LDL-C and apo B levels in FH children not using statins. Importantly, the plasma lipid profile was improved in FH children after dietary counseling where focus was on reducing intake of SFA and dietary cholesterol.

Identification and Treatment of Patients with Homozygous Familial Hypercholesterolaemia: Information and Recommendations from a Middle East Advisory Panel

We present clinical practice guidelines for the diagnosis and treatment of homozygous familial hypercholesterolaemia (HoFH) in the Middle East region. While guidelines are broadly applicable in Europe, in the Middle East we experience a range of confounding factors that complicate disease management to a point whereby the European guidance cannot be applied without significant modification. Specifically, for disease prevalence, the Middle East region has an established epidemic of diabetes and metabolic syndrome that can complicate treatment and mask a clinical diagnosis of HoFH. We have also a high incidence of consanguineous marriages, which increase the risk of transmission of recessive and homozygous genetic disorders. This risk is further augmented in autosomal dominant disorders such as familial 
hypercholesterolaemia (FH), in which a range of defective genes can be transmitted, all of which contribute to the phenotypic expression of the disease. In terms of treatment, we do not have access to lipoprotein apheresis on the same scale as in Europe, and there remains a significant reliance on statins, ezetimibe and the older plasma exchange methods. Additionally, we do not have widespread access to anti-apolipoprotein B therapies and microsomal transfer protein inhibitors. In order to adapt existing global guidance documents on HoFH to the Middle East region, we convened a panel of experts from Oman, Saudi Arabia, UAE, Iran and Bahrain to draft a regional guidance document for HoFH. We also included selected experts from outside the region. This panel statement will form the foundation of a detailed appraisal of the current FH management in the Middle Eastern population and thereby provide a suitable set of guidelines tailored for the region.

Fasting Is Not Routinely Required for Determination of a Lipid Profile: Clinical and Laboratory Implications Including Flagging at Desirable Concentration Cutpoints—A Joint Consensus Statement from the European Atherosclerosis Society and European Federation of Clinical Chemistry and Laboratory Medicine

AIMS

To critically evaluate the clinical implications of the use of non-fasting rather than fasting lipid profiles and to provide guidance for the laboratory reporting of abnormal non-fasting or fasting lipid profiles.

METHODS AND RESULTS

Extensive observational data, in which random non-fasting lipid profiles have been compared with those determined under fasting conditions, indicate that the maximal mean changes at 1–6 h after habitual meals are not clinically significant [+0.3 mmol/L (26 mg/dL) for triglycerides; −0.2 mmol/L (8 mg/dL) for total cholesterol; −0.2 mmol/L (8 mg/dL) for LDL cholesterol; +0.2 mmol/L (8 mg/dL) for calculated remnant cholesterol; −0.2 mmol/L (8 mg/dL) for calculated non-HDL cholesterol]; concentrations of HDL cholesterol, apolipoprotein A1, apolipoprotein B, and lipoprotein(a) are not affected by fasting/non-fasting status. In addition, non-fasting and fasting concentrations vary similarly over time and are comparable in the prediction of cardiovascular disease. To improve patient compliance with lipid testing, we therefore recommend the routine use of non-fasting lipid profiles, whereas fasting sampling may be considered when non-fasting triglycerides are &gt;5 mmol/L (440 mg/dL). For non-fasting samples, laboratory reports should flag abnormal concentrations as triglycerides ≥2 mmol/L (175 mg/dL), total cholesterol ≥5 mmol/L (190 mg/dL), LDL cholesterol ≥3 mmol/L (115 mg/dL), calculated remnant cholesterol ≥0.9 mmol/L (35 mg/dL), calculated non-HDL cholesterol ≥3.9 mmol/L (150 mg/dL), HDL cholesterol ≤1 mmol/L (40 mg/dL), apolipoprotein A1 ≤1.25 g/L (125 mg/dL), apolipoprotein B ≥1.0 g/L (100 mg/dL), and lipoprotein(a) ≥50 mg/dL (80th percentile); for fasting samples, abnormal concentrations correspond to triglycerides ≥1.7 mmol/L (150 mg/dL). Life-threatening concentrations require separate referral for the risk of pancreatitis when triglycerides are &gt;10 mmol/L (880 mg/dL), for homozygous familial hypercholesterolemia when LDL cholesterol is &gt;13 mmol/L (500 mg/dL), for heterozygous familial hypercholesterolemia when LDL cholesterol is &gt;5 mmol/L (190 mg/dL), and for very high cardiovascular risk when lipoprotein(a) &gt;150 mg/dL (99th percentile).

CONCLUSIONS

We recommend that non-fasting blood samples be routinely used for the assessment of plasma lipid profiles. Laboratory reports should flag abnormal values on the basis of desirable concentration cutpoints. Non-fasting and fasting measurements should be complementary but not mutually exclusive.