Homozygous familial hypercholesterolaemia: new insights and guidance for clinicians to improve detection and clinical management. A position paper from the Consensus Panel on Familial Hypercholesterolaemia of the European Atherosclerosis Society

Efficacy and Safety of Lomitapide in Japanese Patients with Homozygous Familial Hypercholesterolemia

Aim: There is an unmet need in Japan for more optimal lipid-lowering therapy (LLT) for patients with homozygous familial hypercholesterolemia (HoFH) who respond inadequately to available drug therapies and/or apheresis, to achieve goals of low-density lipoprotein cholesterol (LDL-C) reduction by 50% or to < 100 mg/dL.

Methods: In this study, Japanese patients with HoFH on stable LLT and diet were treated with lomitapide, initiated at 5 mg/day and escalated to maximum tolerated dose (up to 60 mg/day) over 14 weeks. The primary efficacy endpoint was mean percentage change from baseline to Week 26 in LDL-C. Secondary endpoints included changes in other lipid parameters and safety throughout the 56-week study (including follow-up).

Results: Nine patients entered the efficacy phase of the study and, of these, eight completed 56 weeks. Mean LDL-C was reduced by 42% (p < 0.0001) at 26 weeks, from 199 mg/dL (95% CI: 149–250) at baseline to 118 mg/dL (95% CI: 70–166). A 50% reduction in LDL-C and LDL-C < 100 mg/dL was achieved by five and six of nine patients, respectively, at 26 weeks. After 56 weeks, LDL-C was reduced by 38% (p = 0.0032) from baseline. Significant reductions in non-HDL-C, VLDL-C, triglycerides, and apolipoprotein B were also reported at Week 26. There were no new safety signals and, similar to previous studies, gastrointestinal adverse events were the most common adverse events.

Conclusion: Lomitapide, added to ongoing treatment with other LLTs, was effective in rapidly and significantly reducing the levels of LDL-C and other atherogenic apolipoprotein B-containing lipoproteins in adult Japanese patients with HoFH.

Low-density lipoprotein receptor-negative compound heterozygous familial hypercholesterolemia: Two lifetime journeys of lipid-lowering therapy

We present the case history of 2 patients with low-density lipoprotein receptor-negative compound heterozygous familial hypercholesterolemia who did not receive lipoprotein apheresis. We describe the subsequent effect of all lipid-lowering medications during their life course including resins, statins, ezetimibe, nicotinic acid/laropiprant, mipomersen, and lomitapide. These cases tell the story of siblings affected with this rare disease, who are free of symptoms but still are at a very high cardiovascular disease risk, and their treatment from childhood.

Austrian Lipid Consensus on the management of metabolic lipid disorders to prevent vascular complications: A joint position statement issued by eight medical societies. 2016 update

In 2010, eight Austrian medical societies proposed a joint position statement on the management of metabolic lipid disorders for the prevention of vascular complications. An updated and extended version of these recommendations according to the current literature is presented, referring to the primary and secondary prevention of vascular complications in adults, taking into consideration the guidelines of other societies. The "Austrian Lipid Consensus - 2016 update" provides guidance for individualized risk stratification and respective therapeutic targets, and discusses the evidence for reducing vascular endpoints with available lipid-lowering therapies. Furthermore, specific management in key patient groups is outlined, including subjects presenting with coronary, cerebrovascular, and/or peripheral atherosclerosis; diabetes mellitus and/or metabolic syndrome; nephropathy; and familial hypercholesterolemia.

Estimating the prevalence of generalized and partial lipodystrophy: findings and challenges

BACKGROUND

Lipodystrophy (LD; non-human immunodeficiency virus [HIV]-associated) syndromes are a rare body of disorders for which true prevalence is unknown. Prevalence estimates of rare diseases are important to increase awareness and financial resources. Current qualitative and quantitative estimates of LD prevalence range from ~0.1 to 90 cases/million. We demonstrate an approach to quantitatively estimate LD prevalence (all, generalized, and partial) through a search of 5 electronic medical record (EMR) databases and 4 literature searches.

METHODS

EMR and literature searches were conducted from 2012 to 2014. For the EMR database searches (Quintiles, IMS LifeLink, General Electric Healthcare, and Humedica EMR), LD cases were identified by the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code 272.6 (United Kingdom General Practice Research Database used other diagnostic codes to identify LD) plus additional LD-associated clinical characteristics (patients with HIV or documented HIV treatment were excluded). Expert adjudication of cases was used for the Quintiles database only. Literature searches (PubMed and EMBASE) were conducted for each of the 4 major LD subtypes. Prevalence estimates were determined by extrapolating the total number of cases identified for each search to the database population (EMR search) and European population (literature search).

RESULTS

The prevalence range of all LD across all EMR databases was 1.3-4.7 cases/million. For the adjudicated Quintiles search, the estimated prevalence of diagnosed LD was 3.07 cases/million (95% confidence interval [CI], 2.30-4.02), 0.23 cases/million (95% CI, 0.06-0.59) and 2.84 cases/million (95% CI, 2.10-3.75) for generalized lipodystrophy (GL) and partial lipodystrophy (PL), respectively. For all literature searches, the prevalence of all LD in Europe was 2.63 cases/million (0.96 and 1.67 cases/million for GL and PL, respectively).

CONCLUSION

LD prevalence estimates are at the lower range of previously established numbers, confirming that LD is an ultra-rare disease. The establishment of diagnostic criteria and coding specific to the 4 major LD subtypes and future studies/patient registries are needed to further refine our estimates.

The 1st and the 2nd Italian Consensus Conferences on low-density lipoprotein-apheresis. A practical synopsis and update

The clinical indications and guidelines for low-density lipoprotein (LDL)-apheresis set by the 1st Italian Consensus Conference held in Ostuni in 1990 and completed in 1992, but never published, are reported schematically. In 1994, within the Project "Prevention and control of the factors of the disease (FATMA)" by the Italian National Research Council, subproject 8 "Control of cardiovascular disease", a "Hearing on therapeutic apheresis: need for a target-oriented project" was organised. The meeting was the last scientific initiative on LDL-apheresis supported by public funds in Italy. After roughly two decades of use of LDL-apheresis, new guidelines were required based on the latest scientific evidence. In 2006, the Italian multicentre study on LDL-apheresis Working Group (IMSLDLa-WP), a scientific initiative at national level, was developed. It initially gathered together 19 Italian centres qualified for the application of lipid apheresis and LDL-apheresis (2007-2008), then 23 in 2010, located in the north, south, centre of Italy and in Sicily and Sardinia. The multicentre study aimed to validate the protocol for selecting patients and to create a network between the Italian centres. A secondary objective was the creation of a database of patients with familial hypercholesterolaemia and other severe forms of dyslipidaemia undergoing treatment with LDL-apheresis using the available techniques. Since LDL-apheresis has multidisciplinary treatment indications, the agreement on the new guidelines was reached through a panel of experts, of different medical and surgical specialties, with scientific and medical interest in the treatment indications, application and development of LDL-apheresis. The initiatives of the IMSLDLa-WP led to the 2nd Italian Consensus Conference on LDL-apheresis held in Rome in 2009. The previous and most recent guidelines are reported here synoptically.

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.

Liver transplantation for homozygote familial hypercholesterolemia: the only curative treatment

FH is an autosomal dominant genetic disorder characterized by increased TC and LDL level, which leads to xanthomas, atherosclerosis, and cardiac complications even in childhood. The treatment options are diet, medical treatment, lipid apheresis, and LT. The aim of our study was to analyze our data of patients with FH. Between 2004 and 2015, there were 51 patients who underwent pediatric LT at our center. All patients with FH were identified, and the data were retrospectively analyzed. There were eight patients with homozygous FH in the median age of 10 years (IQR 6-12) who underwent LT. The median pre-operative TC and LDL levels were 611 mg/dL (IQR: 460-844) and 574 mg/dL (IQR: 398-728) and decreased to normal levels 1 week after LT (TC: 193 mg/dL and LDL: 141 mg/dL). Two patients died two and 18 months after LT due to sudden cardiac arrest. Both patients were diagnosed with cardiovascular disease pre-operatively. The LT is the only curative treatment for this disease. To achieve an excellent outcome, it should be performed before the development of cardiovascular disease, because the regression of severe cardiovascular disease after transplantation is limited.

Polygenic Versus Monogenic Causes of Hypercholesterolemia Ascertained Clinically

Objective—

Next-generation sequencing technology is transforming our understanding of heterozygous familial hypercholesterolemia, including revision of prevalence estimates and attribution of polygenic effects. Here, we examined the contributions of monogenic and polygenic factors in patients with severe hypercholesterolemia referred to a specialty clinic.

Approach and Results—

We applied targeted next-generation sequencing with custom annotation, coupled with evaluation of large-scale copy number variation and polygenic scores for raised low-density lipoprotein cholesterol in a cohort of 313 individuals with severe hypercholesterolemia, defined as low-density lipoprotein cholesterol >5.0 mmol/L (>194 mg/dL). We found that (1) monogenic familial hypercholesterolemia–causing mutations detected by targeted next-generation sequencing were present in 47.3% of individuals; (2) the percentage of individuals with monogenic mutations increased to 53.7% when copy number variations were included; (3) the percentage further increased to 67.1% when individuals with extreme polygenic scores were included; and (4) the percentage of individuals with an identified genetic component increased from 57.0% to 92.0% as low-density lipoprotein cholesterol level increased from 5.0 to >8.0 mmol/L (194 to >310 mg/dL).

Conclusions—

In a clinically ascertained sample with severe hypercholesterolemia, we found that most patients had a discrete genetic basis detected using a comprehensive screening approach that includes targeted next-generation sequencing, an assay for copy number variations, and polygenic trait scores.

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.

Systematic review of published Phase 3 data on anti-PCSK9 monoclonal antibodies in patients with hypercholesterolaemia

AIMS

Two anti-proprotein convertase subtilisin/kexin type 9 (PCSK9) monoclonal antibodies, alirocumab and evolocumab, have been approved for the treatment of hypercholesterolaemia in certain patients. We reviewed data from Phase 3 studies to evaluate the efficacy and safety of these antibodies.

METHODS

We systematically reviewed Phase 3 English-language studies in patients with hypercholesterolaemia, published between 1 January 2005 and 20 October 2015. Congress proceedings from 16 November 2012 to 16 November 2015 were also reviewed.

RESULTS

We identified 12 studies of alirocumab and nine of evolocumab, including over 10 000 patients overall. Most studies enrolled patients with hypercholesterolaemia and used anti-PCSK9 antibodies with statins. The ODYSSEY FH I, FH II and HIGH FH alirocumab studies and the RUTHERFORD-2 evolocumab study exclusively recruited patients with heterozygous familial hypercholesterolaemia. Two evolocumab studies focused mainly on homozygous familial hypercholesterolaemia (HoFH): TESLA Part B and TAUSSIG (a TESLA sub-study); only those data for HoFH are reported here. All comparator studies demonstrated a reduction in LDL cholesterol (LDL-C) with the anti-PCSK9 antibodies. No head-to-head studies were conducted between alirocumab and evolocumab. Up to 87% of patients receiving alirocumab and up to 98% receiving evolocumab reached LDL-C goals. Both antibodies were effective and well tolerated across a broad population of patients and in specific subgroups, such as those with type 2 diabetes.

CONCLUSIONS

Using anti-PCSK9 antibodies as add-on therapy to other lipid-lowering treatments or as monotherapy for patients unable to tolerate statins may help patients with high cardiovascular risk to achieve their LDL-C goals.

Early severe coronary artery disease and aortic coarctation in a child with familial hypercholesterolaemia

An 11-year-old boy presented with easy fatigability, multiple xanthomas, and absent pedal pulsations. Laboratory workup showed severe hypercholesterolaemia and non-invasive imaging revealed 'normally functioning' bicuspid aortic valve and tight aortic coarctation. Coronary angiography showed severe right coronary artery (RCA) stenosis. Medical treatment resulted in significant improvement of dyslipidaemia. We successfully performed balloon dilation and stenting of his coarctation, as well as percutaneous coronary intervention for RCA lesion.

Interpretation of the evidence for the efficacy and safety of statin therapy

This Review is intended to help clinicians, patients, and the public make informed decisions about statin therapy for the prevention of heart attacks and strokes. It explains how the evidence that is available from randomised controlled trials yields reliable information about both the efficacy and safety of statin therapy. In addition, it discusses how claims that statins commonly cause adverse effects reflect a failure to recognise the limitations of other sources of evidence about the effects of treatment. Large-scale evidence from randomised trials shows that statin therapy reduces the risk of major vascular events (ie, coronary deaths or myocardial infarctions, strokes, and coronary revascularisation procedures) by about one-quarter for each mmol/L reduction in LDL cholesterol during each year (after the first) that it continues to be taken. The absolute benefits of statin therapy depend on an individual's absolute risk of occlusive vascular events and the absolute reduction in LDL cholesterol that is achieved. For example, lowering LDL cholesterol by 2 mmol/L (77 mg/dL) with an effective low-cost statin regimen (eg, atorvastatin 40 mg daily, costing about £2 per month) for 5 years in 10 000 patients would typically prevent major vascular events from occurring in about 1000 patients (ie, 10% absolute benefit) with pre-existing occlusive vascular disease (secondary prevention) and in 500 patients (ie, 5% absolute benefit) who are at increased risk but have not yet had a vascular event (primary prevention). Statin therapy has been shown to reduce vascular disease risk during each year it continues to be taken, so larger absolute benefits would accrue with more prolonged therapy, and these benefits persist long term. The only serious adverse events that have been shown to be caused by long-term statin therapy-ie, adverse effects of the statin-are myopathy (defined as muscle pain or weakness combined with large increases in blood concentrations of creatine kinase), new-onset diabetes mellitus, and, probably, haemorrhagic stroke. Typically, treatment of 10 000 patients for 5 years with an effective regimen (eg, atorvastatin 40 mg daily) would cause about 5 cases of myopathy (one of which might progress, if the statin therapy is not stopped, to the more severe condition of rhabdomyolysis), 50-100 new cases of diabetes, and 5-10 haemorrhagic strokes. However, any adverse impact of these side-effects on major vascular events has already been taken into account in the estimates of the absolute benefits. Statin therapy may cause symptomatic adverse events (eg, muscle pain or weakness) in up to about 50-100 patients (ie, 0·5-1·0% absolute harm) per 10 000 treated for 5 years. However, placebo-controlled randomised trials have shown definitively that almost all of the symptomatic adverse events that are attributed to statin therapy in routine practice are not actually caused by it (ie, they represent misattribution). The large-scale evidence available from randomised trials also indicates that it is unlikely that large absolute excesses in other serious adverse events still await discovery. Consequently, any further findings that emerge about the effects of statin therapy would not be expected to alter materially the balance of benefits and harms. It is, therefore, of concern that exaggerated claims about side-effect rates with statin therapy may be responsible for its under-use among individuals at increased risk of cardiovascular events. For, whereas the rare cases of myopathy and any muscle-related symptoms that are attributed to statin therapy generally resolve rapidly when treatment is stopped, the heart attacks or strokes that may occur if statin therapy is stopped unnecessarily can be devastating.

The use of targeted exome sequencing in genetic diagnosis of young patients with severe hypercholesterolemia

Familial hypercholesterolemia (FH) is an autosomal dominant disorder. Although genetic testing is an important tool for detecting FH-causing mutations in patients, diagnostic methods for young patients with severe hypercholesterolemia are understudied. This study compares the target exome sequencing (TES) technique with the DNA resequencing array technique on young patients with severe hypercholesterolemia. A total of 20 unrelated patients (mean age 14.8 years) with total cholesterol > 10 mmol/L were included. 12 patient samples were processed by DNA resequencing array, 14 patient samples were processed by TES, and 6 patient samples were processed by both methods. Functional characterization of novel mutations was performed by flow cytometry. The mutation detection rate (MDR) of DNA resequencing array was 75%, while the MDR of TES was 100%. A total of 27 different mutations in the LDLR were identified, including 3 novel mutations and 8 mutations with previously unknown pathogenicity. Functional characterization of c.673delA, c.1363delC, p.Leu575Phe and p.Leu582Phe variants found that all of them are pathogenic. Additionally, 7 patients were diagnosed with Heterozygous FH (HeFH) in which lipid levels were significantly higher than common HeFH patients. This data indicates that TES is a very efficient tool for genetic diagnosis in young patients with severe hypercholesterolemia.

Progressive Aortic Stenosis in Homozygous Familial Hypercholesterolemia After Liver Transplant

Early onset coronary artery disease and aortic calcifications are characteristic features of patients with homozygous familial hypercholesterolemia. Standard medical therapy includes dietary modification, pharmacotherapy, and lipoprotein apheresis to lower serum low-density lipoprotein cholesterol (LDL-C). Liver transplant is a surgical option for the treatment of homozygous familial hypercholesterolemia and can lead to normal cholesterol levels. Vascular calcifications are known to progress despite standard medical therapy and have been reported after liver transplant in the setting of rejection. We present the first report of progressive severe aortic valve stenosis in a patient despite liver transplant with normalization of lipid levels and no history of graft rejection.

Homozygous familial hypercholesterolaemia: update on management

Homozygous familial hypercholesterolaemia (HoFH) is an inherited disease causing an approximately fourfold increase in blood low-density lipoprotein cholesterol (LDLC) from birth compared with the age-matched normal population owing to reduced low-density lipoprotein receptor (LDLR) activity. Such elevated cholesterol is associated with accelerated atheromatous disease, particularly of the aortic root and coronary arteries. However, HoFH is clinically heterogeneous, reflecting residual low-density lipoprotein receptor (LDLR) activity. The main objective in treating children may be stated to be the avoidance of irreversible cardiac damage requiring heart transplantation by sufficient lowering of blood cholesterol. Lipoprotein apheresis or plasmapheresis are safe means of lowering cholesterol but may be insufficient on their own. Statin drugs, PCSK9 inhibitors ezetimibe and bile acid sequestrants are relatively ineffective if LDLR activity is lacking, but should be used if effective. Two new drugs, lomitapide and mipomersen, have been licensed specifically for HoFH by some regulatory authorities. They work by reducing LDL production rate. They have been associated with fatty liver in adults. Evidence of safety in children is lacking. An alternative is liver transplantation, which replaces the missing LDLR and normalises cholesterol. Clinicians are faced with a dilemma in choosing between these options or deferring such treatment associated with potential harm. Individual case descriptions are an important means of informing clinical judgement. Management of the two cases described in this issue is discussed in the light of modern developments in transplantation and pharmacotherapy.

Referral Patterns and Cascade Screening for Familial Hypercholesterolemia in a Pediatric Lipid Clinic

Charts of 42 children with familial hypercholesterolemia from a dyslipidemia clinic were reviewed for initial cholesterol screen indication and cascade screening results. Indications were universal screening (8/28 after guideline release, none before), family history (26/42), risk factor (5/42), and other (3/42). Cascade screening identified 63 relatives with unknown familial hypercholesterolemia.

Homozygous familial hypercholesterolaemia in two boys aged 5 and 10 years

Familial hypercholesterolaemia (FH) is an autosomal dominant lipid disorder. Homozygous FH (HFH), though rare, presents in early childhood. Two different presentations of HFH are reported. The first child presented at 5 years of age with xanthomas on the knees, elbows and buttocks and failure to thrive since the second year of life. He was found to be hypertensive with moderate aortic regurgitation. He is now stable on statins and antihypertensives. The second child presented at 10 years of age with multiple xanthomas and severe aortic stenosis. He died of refractory cardiac failure despite emergency aortic balloon valvoplasty due to diffuse coronary artery disease. Strong clinical suspicion can aid early diagnosis and delay cardiovascular complications.

National Lipid Association Annual Summary of Clinical Lipidology 2016

The National Lipid Association (NLA) Annual Summary of Clinical Lipidology is a yearly updated summary of principles important to the patient-centered evaluation, management, and care of patients with dyslipidemia. This summary is intended to be a "living document," with future annual updates based on emerging science, clinical considerations, and new NLA Position, Consensus, and Scientific Statements, thus providing an ongoing resource that applies the latest in medical science towards the clinical management of patients with dyslipidemia. Topics include the NLA Recommendations for Patient-Centered Management of Dyslipidemia, genetics, Familial Hypercholesterolemia, secondary causes of dyslipidemia, biomarkers and advanced lipid testing, nutrition, physical activity, obesity, adiposopathy, metabolic syndrome, diabetes mellitus, lipid pharmacotherapy, lipid-altering drug interactions, lipoprotein apheresis, dyslipidemia management and treatment based upon age (children, adolescents, and older individuals), dyslipidemia considerations based upon race, ethnicity and gender, dyslipidemia and human immune virus infection, dyslipidemia and immune disorders, adherence strategies and collaborative care, and lipid-altering drugs in development. Hyperlinks direct the reader to sentinel online tables, charts, and figures relevant to lipidology, access to online atherosclerotic cardiovascular disease risk calculators, worldwide lipid guidelines, recommendations, and position/scientific statements, as well as links to online audio files, websites, slide shows, applications, continuing medical education opportunities, and patient information.

Spectrum of mutations in homozygous familial hypercholesterolemia in India, with four novel mutations

BACKGROUND AND AIMS

Homozygous familial hypercholesterolemia (FH) is a rare but serious, inherited disorder of lipid metabolism characterized by very high total and LDL cholesterol levels from birth. It presents as cutaneous and tendon xanthomas since childhood, with or without cardiac involvement. FH is commonly caused by mutations in three genes, i.e. LDL receptor (LDLR), apolipoprotein B (ApoB) and PCSK9. We aimed to determine the spectrum of mutations in cases of homozygous FH in Asian Indians and evaluate if there was any similarity to the mutations observed in Caucasians.

METHODS

Sixteen homozygous FH subjects from eleven families were analyzed for mutations by Sanger sequencing. Large rearrangements in LDLR gene were evaluated by multiplex ligation probe dependent amplification (MLPA) technique.

RESULTS

Ten mutations were observed in LDLR gene, of which four mutations were novel. No mutation was detected in ApoB gene and common PCSK9 mutation (p.D374Y). Fourteen cases had homozygous mutations; one had compound heterozygous mutation, while no mutation was detected in one clinically homozygous case. We report an interesting "Triple hit" case with features of homozygous FH.

CONCLUSIONS

The spectrum of mutations in the Asian Indian population is quite heterogeneous. Of the mutations identified, 40% were novel. No mutation was observed in exons 3, 9 and 14 of LDLR gene, which are considered to be hot spots in studies done on Asian Indians in South Africa. Early detection followed by aggressive therapy, and cascade screening of extended families has been initiated to reduce the morbidity and mortality in these patients.

Lipid Management in Diabetes with a Focus on Emerging Therapies

We reviewed the current and potential future management of dyslipidemia in patients with diabetes, with a focus on reduction of risk for macrovascular disease. We considered novel dyslipidemia therapies, in particular, inhibitors of proprotein convertase subtilisin kexin 9 (PCSK9), which have been approved in Canada for reducing low-density lipoprotein (LDL) cholesterol in certain patient groups. We searched for English-language randomized clinical trials (RCTs) of lipid-lowering modalities, mainly since 2012, that included patients with diabetes. The results from some RCTs may have future impacts on the approach to patients with diabetes. In particular, ezetimibe added to statins in the context of acute coronary syndromes seems to have particular benefits in patients with diabetes. Also, patients with diabetes show no differences, so far, from patients without diabetes with respect to efficacy of PCSK9 inhibitors in LDL cholesterol reduction and also in the frequency of adverse effects. RCTs of clinical outcomes with PCSK9 inhibitors performed exclusively in patients with diabetes are desirable, but approval of these agents for use in Canada has occurred before the availability of such results. Clinicians will have to gauge whether certain subjects with diabetes might benefit from this therapy, such as those with superimposed familial dyslipidemia, those with recurrent cardiovascular events and recalcitrant LDL cholesterol levels despite maximally tolerated statin therapy and those with high cardiovascular risk who cannot tolerate any dose of statins.

LDL-Cholesterol: Standards of Treatment 2016: A German Perspective

Decreasing low-density lipoprotein cholesterol (LDL-C) is one of the few established and proven principles for the prevention and treatment of atherosclerosis. The higher the individual cardiovascular risk, the higher the benefit of lipid-lowering pharmacotherapy. Therefore, treatment options are chosen based on a patient's total cardiovascular risk. The latter depends not only on the levels of LDL-C but also on the presence of cardiovascular disease (CVD) and on the number and severity of other risk factors. Current guidelines recommend the lowering of LDL-C to 115 mg/dl (3 mmol/l) in patients with low and moderate risk. The LDL-C treatment target is <100 mg/dl (2.6 mmol/l) for patients at high risk and <70 mg/dl (1.8 mmol/l) for patients at very high risk. Although lifestyle measures remain a fundamental part of treatment, many patients require drug therapy to achieve their LDL-C targets. Statins are the drugs of choice, with other options including ezetimibe and the newly available monoclonal antibodies against PCSK9 (proprotein convertase subtilisin/kexin type 9). In some cases, bile acid-binding sequestrants and fibrates can also be considered. Nicotinic acid is no longer available in Germany. PCSK9 antibodies decrease LDL-C about 50-60 % and are well tolerated. Their effects on clinical endpoints are being investigated in large randomized trials. The aim of the present review is to summarize the current guidelines and treatment options for hypercholesterolemia. Moreover, we provide an appraisal of PCSK9 antibodies and propose their use in selected patient populations, particularly in those at very high cardiovascular risk whose LDL-C levels under maximally tolerated lipid-lowering therapy are significantly over their treatment target.

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.

Targeting microsomal triglyceride transfer protein and lipoprotein assembly to treat homozygous familial hypercholesterolemia

Homozygous familial hypercholesterolemia (HoFH) is a polygenic disease arising from defects in the clearance of plasma low-density lipoprotein (LDL), which results in extremely elevated plasma LDL cholesterol (LDL-C) and increased risk of atherosclerosis, coronary heart disease, and premature death. Conventional lipid-lowering therapies, such as statins and ezetimibe, are ineffective at lowering plasma cholesterol to safe levels in these patients. Other therapeutic options, such as LDL apheresis and liver transplantation, are inconvenient, costly, and not readily available. Recently, lomitapide was approved by the Federal Drug Administration as an adjunct therapy for the treatment of HoFH. Lomitapide inhibits microsomal triglyceride transfer protein (MTP), reduces lipoprotein assembly and secretion, and lowers plasma cholesterol levels by over 50%. Here, we explain the steps involved in lipoprotein assembly, summarize the role of MTP in lipoprotein assembly, explore the clinical and molecular basis of HoFH, and review pre-clinical studies and clinical trials with lomitapide and other MTP inhibitors for the treatment of HoFH. In addition, ongoing research and new approaches underway for better treatment modalities are discussed.

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.

Fasting and nonfasting triglycerides in cardiovascular and other diseases

Moderately elevated plasma/serum triglycerides (2-10 mmol/l) signalize increased risk for cardiovascular disease or presence of non-alcoholic steatohepatitis. Extremely elevated triglycerides (more than 10 mmol/l) signalize increased risk for pancreatitis and lipemia retinalis. The concentration of triglycerides is regulated by many genetic and nongenetic factors. Extremely elevated triglycerides not provoked by nutritional factors, especially inappropriate alcohol intake are more likely to have a monogenic cause. On the contrary, mildly to moderately elevated triglycerides are often caused by polygenic disorders; these could be also associated with central obesity, insulin resistance, and diabetes mellitus. Concentration of triglycerides is also closely interconnected with presence of atherogenic remnant lipoproteins, impaired reverse cholesterol transport and more atherogenic small LDL particles. In general, there is tight association between triglycerides and many other metabolic factors including intermediate products of lipoprotein metabolism which are frequently atherogenic. Therefore, reliable evaluation of the independent role of triglycerides especially in atherosclerosis and cardiovascular disease is difficult. In individual cases values of HDL cholesterol, non-HDL cholesterol (total minus HDL cholesterol), non-HDL/nonLDL cholesterol (total minus HDL minus LDL cholesterol, especially in nonfasting status), atherogenic index of plasma and/or apolipoprotein B could help in decisions regarding aggressiveness of treatment.

New Approaches in Detection and Treatment of Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is an autosomal dominant genetic disorder that clinically leads to increased low density lipoprotein-cholesterol (LDL-C) levels. As a consequence, FH patients are at high risk for cardiovascular disease (CVD). Mutations are found in genes coding for the LDLR, apoB, and PCSK9, although FH cannot be ruled out in the absence of a mutation in one of these genes. It is pivotal to diagnose FH at an early age, since lipid lowering results in a decreased risk of cardiovascular complications especially if initiated early, but unfortunately FH is largely underdiagnosed. While a number of clinical criteria are available, identification of a pathogenic mutation in any of the three aforementioned genes is seen by many as a way to establish a definitive diagnosis of FH. It should be remembered that clinical treatment is based on LDL-C levels and not solely on presence or absence of genetic mutations as LDL-C is what drives risk. Traditionally, mutation detection has been done by means of dideoxy sequencing. However, novel molecular testing methods are gradually being introduced. These next generation sequencing-based methods are likely to be applied on broader scale once their efficacy and effect on cost are being established. Statins are the first-line therapy of choice for FH patients as they have been proven to reduce CVD risk across a range of conditions including hypercholesterolemia (though not specifically tested in FH). However, in a significant proportion of FH patients LDL-C goals are not met, despite the use of maximal statin doses and additional lipid-lowering therapies. This underlines the need for additional therapies, and inhibition of PCSK9 and CETP is among the most promising new therapeutic options. In this review, we aim to provide an overview of the latest information about the definition, diagnosis, screening, and current and novel therapies for FH.

Novel Therapies for Familial Hypercholesterolemia

OPINION STATEMENT

Both HeFH and HoFH require dietary and lifestyle modification. Pharmacotherapy of adult HeFH patients is largely driven by the American Heart Association (AHA) algorithm. A high-potency statin is started initially with a goal low-density lipoprotein cholesterol (LDL-C) reduction of >50 %. The LDL-C target is adjusted to <100 or <70 mg/dL in subjects with coronary artery disease (CAD) with ezetimibe being second line. If necessary, a third adjunctive therapy, such as a PSCK9 inhibitor (not yet approved in children) or bile acid-binding resin, can be added. Finally, LDL-C apheresis can be considered in patients with LDL-C >300 mg/dL (or >200 mg/dL with significant CAD, although now approved for LDL-C as low as 160 mg/dL with CAD). Due to the early, severe LDL-C elevation in HoFH patients, concerning natural history, rarity of the condition, and nuances of treatment, all HoFH patients should be treated at a pediatric or adult center with HoFH experience. LDL-C apheresis should be considered as early as 5 years of age. However, apheresis availability and tolerability is limited and pharmacotherapy is required. Generally, the AHA algorithm with reference to the European Atherosclerosis Society Consensus Panel recommendations is reasonable with all patients initiated on high-dose, high-potency statin, ezetimibe, and bile acid-binding resins. In most, additional LDL-C lowering is required with PCSK9 inhibitors and/or lomitapide or mipomersen. Liver transplantation can also be considered at experienced centers as a last resort.

Double-heterozygous autosomal dominant hypercholesterolemia: Clinical characterization of an underreported disease

INTRODUCTION

Autosomal dominant hypercholesterolemia (ADH), characterized by high-plasma low-density lipoprotein cholesterol (LDL-C) levels and premature cardiovascular disease (CVD) risk, is caused by mutations in LDLR, APOB, and/or PCSK9.

OBJECTIVE

To describe the clinical characteristics of "double-heterozygous carriers," with 2 mutations in 2 different ADH causing genes, that is, LDLR and APOB or LDLR and PCSK9.

METHODS

Double heterozygotes were identified in the database of the national referral laboratory for DNA diagnostics of inherited dyslipidemias. We collected the medical data (comprising lipids and CVD events) from double heterozygotes and compared these with data from their heterozygous and unaffected relatives and homozygote/compound heterozygous LDLR mutation carriers, identified in a previously described cohort (n = 45).

RESULTS

A total of 28 double heterozygotes (23 LDLR/APOB and 5 LDLR/PCSK9 mutation carriers) were identified. Off treatment, LDL-C levels were significantly higher in double heterozygotes (mean ± SD, 8.4 ± 2.8 mmol/L) compared with 28 heterozygous (5.6 ± 2.2) and 18 unaffected relatives (2.5 ± 1.1; P ≤ .01 for all comparisons) and significantly lower compared with homozygous/compound heterozygous LDLR mutation carriers (13.0 ± 5.1; P < .001).

CONCLUSIONS

Double-heterozygous carriers of mutations in ADH genes express an intermediate phenotype compared with heterozygous and homozygous/compound heterozygous carriers and might well be misconceived to suffer from a severe form of heterozygous ADH. The molecular identification of double heterozygosity is of relevance from both a screening and an educational perspective.

Recent Developments in Gene Therapy for Homozygous Familial Hypercholesterolemia

Homozygous familial hypercholesterolemia (HoFH) is a life-threatening Mendelian disorder with a mean life expectancy of 33 years despite maximally tolerated standard lipid-lowering therapies. This disease is an ideal candidate for gene therapy, and in the last few years, a number of exciting developments have brought this approach closer to the clinic than ever before. In this review, we discuss in detail the most advanced of these developments, a recombinant adeno-associated virus (AAV) vector carrying a low-density lipoprotein receptor (LDLR) transgene which has recently entered phase 1/2a testing. We also review ongoing development of approaches to enhance transgene expression, improve the efficiency of hepatocyte transduction, and minimize the AAV capsid-specific adaptive immune response. We include a summary of key gene therapy approaches for HoFH in pre-clinical development, including RNA silencing of the gene encoding HMG-CoA reductase (HMGCR) and induced pluripotent stem cell transplant therapy.

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.

Proprotein Convertase Subtilisin Kexin Type 9 Inhibition for Autosomal Recessive Hypercholesterolemia-Brief Report

OBJECTIVE

Proprotein convertase subtilisin kexin type 9 (PCSK9) inhibitors lower low-density lipoprotein (LDL) cholesterol in the vast majority of patients with autosomal dominant familial hypercholesterolemia. Will PCSK9 inhibition with monoclonal antibodies, in particular alirocumab, be of therapeutic value for patients with autosomal recessive hypercholesterolemia (ARH)?

APPROACH AND RESULTS

Primary lymphocytes were obtained from 28 genetically characterized ARH patients and 11 controls. ARH lymphocytes treated with mevastatin were incubated with increasing doses of recombinant PCSK9 with or without saturating concentrations of alirocumab. Cell surface LDL receptor expression measured by flow cytometry and confocal microscopy was higher in ARH than in control lymphocytes. PCSK9 significantly reduced LDL receptor expression in ARH lymphocytes albeit to a lower extent than in control lymphocytes (25% versus 76%, respectively), an effect reversed by alirocumab. Fluorescent LDL cellular uptake, also measured by flow cytometry, was reduced in ARH lymphocytes compared with control lymphocytes. PCSK9 significantly lowered LDL cellular uptake in ARH lymphocytes, on average by 18%, compared with a 46% reduction observed in control lymphocytes, an effect also reversed by alirocumab. Overall, the effects of recombinant PCSK9, and hence of alirocumab, on LDL receptor expression and function were significantly less pronounced in ARH than in control cells.

CONCLUSIONS

PCSK9 inhibition with alirocumab on top of statin treatment has the potential to lower LDL cholesterol in some autosomal recessive hypercholesterolemia patients.

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.

A systematic review of current studies in patients with familial hypercholesterolemia by use of national familial hypercholesterolemia registries

PURPOSE OF REVIEW

More than 25 million are expected to have familial hypercholesterolemia worldwide. The risk of cardiovascular disease (CVD) in familial hypercholesterolemia is not clear and register studies represent a valuable tool to get such data, which will be discussed in the present paper.

RECENT FINDING

A systematic review of current familial hypercholesterolemia studies, by use of National familial hypercholesterolemia registries was performed from 1980 to 2016. This review shows that familial hypercholesterolemia patients have a high prevalence of CVD also in the time period after statins became available. The patient group does not reach recommended target values for lipids, and have a significantly higher CVD mortality as compared with the general population according to age and sex.

SUMMARY

The review underscores the importance of establishing National familial hypercholesterolemia registries with complete datasets on familial hypercholesterolemia patients to improve early diagnostics, therapeutics and long-term follow-up to prevent the premature CVD events and deaths in this patient group.