Long-Term LDL-Apheresis Treatment and Dynamics of Circulating miRNAs in Patients with Severe Familial Hypercholesterolemia

Lipoprotein apheresis (LA) is a therapeutic option for patients with severe hypercholesterolemia who have persistently elevated LDL-C levels despite attempts at drug therapy. MicroRNAs (miRNAs), important posttranscriptional gene regulators, are involved in the pathogenesis of atherosclerosis. Our study aimed to monitor the dynamics of twenty preselected circulating miRNAs in patients under long-term apheresis treatment. Plasma samples from 12 FH patients (men = 50%, age = 55.3 ± 12.2 years; mean LA overall treatment time = 13.1 ± 7.8 years) were collected before each apheresis therapy every sixth month over the course of four years of treatment. Eight complete follow-up (FU) samples were measured in each patient. Dynamic changes in the relative quantity of 6 miRNAs (miR-92a, miR-21, miR-126, miR-122, miR-26a, and miR-185; all p < 0.04) during FU were identified. Overall apheresis treatment time influenced circulating miR-146a levels (p < 0.04). In LDLR mutation homozygotes (N = 5), compared to heterozygotes (N = 7), we found higher plasma levels of miR-181, miR-126, miR-155, and miR-92a (all p < 0.03). Treatment with PCSK9 inhibitors (N = 6) affected the plasma levels of 7 miRNAs (miR-126, miR-122, miR-26a, miR-155, miR-125a, miR-92a, and miR-27a; all p < 0.04). Long-term monitoring has shown that LA in patients with severe familial hypercholesterolemia influences plasma circulating miRNAs involved in endothelial dysfunction, cholesterol homeostasis, inflammation, and plaque development. The longer the treatment using LA, the better the miRNA milieu depicting the potential cardiovascular risk.

Plaque burden is associated with minimal intimal coverage following drug-eluting stent implantation in an adult familial hypercholesterolemia swine model

Safety and efficacy of coronary drug-eluting stents (DES) are often preclinically tested using healthy or minimally diseased swine. These generally show significant fibrotic neointima at follow-up, while in patients, incomplete healing is often observed. The aim of this study was to investigate neointima responses to DES in swine with significant coronary atherosclerosis. Adult familial hypercholesterolemic swine (n = 6) received a high fat diet to develop atherosclerosis. Serial OCT was performed before, directly after, and 28 days after DES implantation (n = 14 stents). Lumen, stent and plaque area, uncovered struts, neointima thickness and neointima type were analyzed for each frame and averaged per stent. Histology was performed to show differences in coronary atherosclerosis. A range of plaque size and severity was found, from healthy segments to lipid-rich plaques. Accordingly, neointima responses ranged from uncovered struts, to minimal neointima, to fibrotic neointima. Lower plaque burden resulted in a fibrotic neointima at follow-up, reminiscent of minimally diseased swine coronary models. In contrast, higher plaque burden resulted in minimal neointima and more uncovered struts at follow-up, similarly to patients' responses. The presence of lipid-rich plaques resulted in more uncovered struts, which underscores the importance of advanced disease when performing safety and efficacy testing of DES.

Gene Therapy for Paediatric Homozygous Familial Hypercholesterolaemia

The clinical outcome for children and adolescents with homozygous familial hypercholesterolaemia (HoFH) can be devastating, and treatment options are limited in the presence of a null variant. In HoFH, atherosclerotic risk accumulates from birth. Gene therapy is an appealing treatment option as restoration of low-density lipoprotein receptor (LDLR) gene function could provide a cure for HoFH. A clinical trial using a recombinant adeno-associated vector (rAAV) to deliver LDLR DNA to adult patients with HoFH was recently completed; results have not yet been reported. However, this treatment strategy may face challenges when translating to the paediatric population. The paediatric liver undergoes substantial growth which is significant as rAAV vector DNA persists primarily as episomes (extra-chromosomal DNA) and are not replicated during cell division. Therefore, rAAV-based gene addition treatment administered in childhood would likely only have a transient effect. With over 2,000 unique variants in LDLR, a goal of genomic editing-based therapy development would be to treat most (if not all) mutations with a single set of reagents. For a robust, durable effect, LDLR must be repaired in the genome of hepatocytes, which could be achieved using genomic editing technology such as clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 and a DNA repair strategy such as homology-independent targeted integration. This review discusses this issue in the context of the paediatric patient group with severe compound heterozygous or homozygous null variants which are associated with aggressive early-onset atherosclerosis and myocardial infarction, together with the important pre-clinical studies that use genomic editing strategies to treat HoFH in place of apheresis and liver transplantation.

Improved extracellular vesicle-based mRNA delivery for familial hypercholesterolemia treatment

Extracellular vesicle (EV)-based low-density lipoprotein receptor (Ldlr) mRNA delivery showed excellent therapeutic effects in treating familial hypercholesterolemia (FH). Nevertheless, the loading inefficiency of EV-based mRNA delivery presents a significant challenge. Recently, RNA-binding proteins (RBPs) have been fused to EV membrane proteins for selectively encapsulating targeted RNAs to promote loading efficiency. However, the strong interaction between therapeutic RNAs and RBPs prevents RNA release from endosomes to the cytosol in the recipient cells. In this study, an improved strategy was developed for efficient encapsulation of Ldlr mRNA into EVs in donor cells and controllable release in recipient cells. Methods: The MS2 bacteriophage coat protein (CD9-MCP) fusion protein, Ldlr mRNA, and a customized MS2 containing RNA aptamer base-pair matched with Ldlr mRNA were expressed in donor cells. Cells receiving the above therapeutic EVs were simultaneously treated with EVs containing "Ldlr releaser" with a sequence similar to the recognition sites in Ldlr mRNA. Therapeutic effects were analyzed in Ldlr-/- mice receiving EV treatments via the tail vein. Results: In vitro experiments demonstrated improved loading efficiency of Ldlr mRNA in EVs via MS2-MCP interaction. Treatment of "Ldlr releaser" competitively interacted with MS2 aptamer with higher affinity and released Ldlr mRNA from CD9-MCP for efficient translation. When the combinatory EVs were delivered into recipient hepatocytes, the robust LDLR expression afforded therapeutic benefits in Ldlr-/- mice. Conclusion: We proposed an EV-based mRNA delivery strategy for enhanced encapsulation of therapeutic mRNAs in EVs and RNA release into the cytosol for translation in recipient cells with great potential for gene therapy.

Cost-effectiveness and Return on Investment of a Nationwide Case-Finding Program for Familial Hypercholesterolemia in Children in the Netherlands

Importance

The Netherlands is one of the few countries that has a long-term history of active screening for familial hypercholesterolemia (FH), enabling health-economic analyses.

Objective

To investigate cost-effectiveness and the return on investment (ROI) of a nationwide cascade case-finding and preventive treatment program starting with identification of FH in children and treatment, from both a societal and health care perspective.

Design, Setting, and Participants

Cascade case-finding and early preventive treatment were modeled to simulate the progression of disease and costs of 10-year-olds suspected of having heterozygous FH over a lifetime. The model consisted of 3 health states: alive without coronary heart disease (CHD), alive with CHD, and deceased. Mendelian randomization analysis was used to quantify the risk of a first CHD event as a function of age and total lifetime exposure to low-density lipoprotein cholesterol. Cost-effectiveness was defined as €20 000 ($21 800) per QALYs (quality-adjusted life-years) gained, using incremental cost-effectiveness ratios (ICERs). All future benefits and costs were discounted annually by 1.5% and 4%, respectively.

Interventions

The study compared 2 strategies: (1) cascade screening and initiation of treatment with statins in children (mean age, 10 years) and (2) no screening, later detection, and treatment.

Main Outcomes and Measures

Outcome of interest included cost, detection, and successful treatment of FH in terms of life-years gained and QALYs. The clinical and cost outputs for each model in the 2 scenarios (early detection and treatment and later detection and treatment) were totaled to determine the overall cost-effectiveness and ROI attributed to implementation of the Dutch FH program.

Results

In this model constructed to simulate the progression of FH in 1000 hypothetical 10-year-olds, from a health care perspective, the program would gain 2.53 QALYs per person, at an additional cost of €23 365 ($25 468) (both discounted). These equated to an ICER of €9220 ($10 050) per QALY gained. From the societal perspective, the detection and treatment program were cost saving over a lifetime compared with no cascade screening for FH. The ROI for the detection and treatment program for FH in children was €8.37 ($9.12).

Conclusions and Relevance

The findings of this study suggest that the early detection and treatment program for FH in children may offer a good value for investment, being both health and cost saving. The findings and interpretations are conditional on assumptions inherent in the health economic model.

How Can Implementation Science Improve the Care of Familial Hypercholesterolaemia?

PURPOSE OF REVIEW

Describe the application of implementation science to improve the detection and management of familial hypercholesterolaemia.

RECENT FINDINGS

Gaps between evidence and practice, such as underutilization of genetic testing, family cascade testing, failure to achieve LDL-cholesterol goals and low levels of knowledge and awareness, have been identified through clinical registry analyses and clinician surveys. Implementation science theories, models and frameworks have been applied to assess barriers and enablers in the literature specific to local contextual factors (e.g. stages of life). The effect of implementation strategies to overcome these factors has been evaluated; for example, automated identification of individuals with FH or training and education to improve statin adherence. Clinical registries were identified as a key infrastructure to monitor, evaluate and sustain improvements in care. The expansion in evidence supporting the care of familial hypercholesterolaemia requires a similar expansion of efforts to translate new knowledge into clinical practice.

Management and clinical outcomes of patients with homozygous familial hypercholesteremia in Saudi Arabia

We report the incidence, patient characteristic with clinical outcomes in patients with homozygous familial hypercholesterolemia (HoFH) in Saudi Arabia. This is a retrospective and prospective, single center study which included 37 patients 14 years and older enrolled and followed up between 2018-2021 for three years. 46% were females, 78% were offspring of consanguineous marriage. LDLR mutation was in 78% and LDL-C/LDLRAP in 3% of patients. Mean LDL-C at the first presentation was 14.2±3.7 mmol/L, average Dutch lipid score was 20.9±6.24. LDL apheresis was performed on 70% of patients. Most patients were on ezetimibe (92%), high-dose statins ( 84%) and  PCSK9 inhibitors (32%). 48.6% had aortic stenosis, out of which 30% had severe aortic stenosis. Ten underwent aortic valve surgery (5 mechanical valve, 3 Ross procedure, 1 aortic valve repair, 1 bioprosthetic valve) and one had transcatheter aortic valve implantation (TAVI). Coronary artery bypass surgery (CABG) was performed on 32% and percutaneous intervention (PCI) on 11% of patients. HoFH patients have complex diseases with high morbidity and mortality, and benefit from a highly specialized multidisciplinary clinic to address their clinical needs. Although there are several therapeutic agents on the horizon, early diagnosis, and treatment of HoFH remain critical to optimize patient outcomes.

[Identifying possible homozygous familial hypercholesterolemia patients: an Italian experts' opinion]

Homozygous familial hypercholesterolemia (HoFH) is a rare genetic disease characterized by high plasma levels of low-density lipoprotein cholesterol (LDL-C) and massive risk of premature atheromasia and cardiovascular events. HoFH is caused by mutations in several genes, such as LDLR, APOB, PCSK9 and LDLRAP1. If untreated, the average age of death is 18 years old, but fatalities within the first 5 years of age have been recorded. Therefore, early diagnosis and treatment are crucial, in order to prevent and/or delay the cardiovascular complications of LDL-C exposure. Because HoFH is a rare disorder, it is not frequently encountered in daily clinical practice at the primary/secondary unspecialized cardiological centers. Then the availability of practical indications helping to identify HoFH patients or to arise a suspect of HoFH is particularly strategic to promptly start the appropriate lipid-lowering therapy. For such a purpose, a group of Italian experts suggests three useful algorithms to identify cases requiring accurate and specialized clinical evaluation as potential HoFH patients. These cases with suspected HoFH should be addressed to specialized centres for the optimal management of these patients.

New algorithms for treating homozygous familial hypercholesterolemia

PURPOSE OF REVIEW

We reviewed current and future therapeutic options for patients with homozygous familial hypercholesterolemia (HoFH) and place this evidence in context of an adaptable treatment algorithm.

RECENT FINDINGS

Lowering LDL-C levels to normal in patients with HoFH is challenging, but a combination of multiple lipid-lowering therapies (LLT) is key. Patients with (near) absence of LDL receptor expression are most severely affected and frequently require regular lipoprotein apheresis on top of combined pharmacologic LLT. Therapies acting independently of the LDL receptor pathway, such as lomitapide and evinacumab, are considered game changers for many patients with HoFH, and may reduce the need for lipoprotein apheresis in future. Liver transplantation is to be considered a treatment option of last resort. Headway is being made in gene therapy strategies, either aiming to permanently replace or knock out key lipid-related genes, with first translational steps into humans being made. Cardiovascular disease risk management beyond LDL-C, such as residual Lp(a) or inflammatory risk, should be evaluated and addressed accordingly in HoFH.

SUMMARY

Hypercholesterolemia is notoriously difficult to control in most patients with HoFH, but multi-LLT, including newer drugs, allows reduction of LDL-C to levels unimaginable until a few years ago. Cost and availability of these new therapies are important future challenges to be addressed.

Introducing genetic testing with case finding for familial hypercholesterolaemia in primary care: qualitative study of patient and health professional experience

BACKGROUND

Familial hypercholesterolaemia (FH) is a common inherited condition causing elevated cholesterol, premature heart disease, and early death. Although FH can be effectively treated, over 80% of people with FH remain undetected.

AIM

To explore patient and health professional experiences of introducing genetic testing with case finding for FH in primary care.

DESIGN AND SETTING

Qualitative study in UK general practice.

METHOD

Semi-structured interviews with a purposeful sample of 41 participants (24 patients and 17 health professionals) from eight practices, using an electronic case-finding tool (FAMCAT) to identify patients with higher likelihood of having FH and who were then offered diagnostic genetic testing in primary care. Data were analysed thematically.

RESULTS

While prior awareness of FH was low, patients were unsurprised to be identified as being at risk, and positive about being offered genetic testing by their practice. Patients not found to have FH were relieved, although some felt frustrated that their high cholesterol lacked a clear cause. Those confirmed to have FH largely expected and accepted this outcome. Practitioners saw detection of FH as an important new opportunity for preventive care. They found the case-finding tool easy to apply and noted patients' high uptake of genetic testing. While they were comfortable referring appropriate patients for further specialist management, GPs sought clearer definition about responsibility for identification and long- term care of FH in future care pathways.

CONCLUSION

Introducing genetic testing with electronic case finding for FH in primary care was positively experienced by patients and practitioners. Further development of this approach could help improve detection of FH in the general population.

[Lipoprotein apheresis in patients with familial hypercholesterolemia: a single center research]

Objective: We evaluated the safety and efficacy of lipoprotein apheresis (LA) in patients with familial hypercholesterolemia (FH) who can't reach low-density lipoprotein cholesterol(LDL-C) target goals with the maximal tolerated dose of lipid-lowering agents. Methods: This was a retrospective cross-sectional study. Between February 2015 and November 2019, patients with FH who were admitted in Fuwai hospital and treated with LA were consecutively enrolled. Based on intensive lipid-lowering agents, these patients received LA by double filtration plasma pheresis (DFPP) method. The changes of lipid levels such as LDL-C and lipoprotein(a)[Lp(a)] were compared before and after LA treatment, and the changes of immunoglobulin (Ig) concentration and LA-related adverse effects were also discussed. Results: A total of 115 patients with FH were enrolled in this study, of which 8 cases were homozygous FH and 107 cases were heterozygous FH. The age was (43.9±12.2) years and there were 75 (65.2%) males, and 108 (93.8%) with coronary artery disease. For pre-and immediately after LA treatment, the LDL-C was (5.20±2.94) mmol/L vs. (1.83±1.08) mmol/L, Lp(a) concentration was 428.70(177.00, 829.50)mg/L vs. 148.90(75.90, 317.00) mg/L (P<0.001), with a decrease of 64.2% and 59.8% respectively. The levels of IgG and IgA measured 1 day after LA treatment were both in the normal range and IgM concentration was below the reference value, the reductions of which were 15.1%, 25.0% and 58.7% respectively (P<0.001). Six patients had mild symptoms of nausea, hypotension dyspnea and palpitation, the symptoms were relieved by symptomatic treatment. Conclusion: For patients with FH who do not achieve LDL-C target goal with the maximal tolerated lipid-lowering agents, especially those with elevated Lp(a) levels, LA, which can significantly further reduce LDL-C and Lp(a) levels, is an effective and safe option.

Clinical decision support for familial hypercholesterolemia (CDS-FH): Rationale and design of a cluster randomized trial in primary care

BACKGROUND

Familial hypercholesterolemia (FH) is an underdiagnosed and undertreated genetic disorder with high risk of premature atherosclerotic cardiovascular disease and death. Clinical decision support (CDS) systems have the potential to aid in the identification and management of patients with FH. Prior studies using computer-based systems to screen patients for FH have shown promising results, but there has been no randomized controlled trial conducted. The aim of the current cluster randomized study is to evaluate if a CDS can increase the identification of FH.

METHODS

We have developed a CDS integrated in the electronic health records that will be activated in patients with elevated cholesterol levels (total cholesterol >8 mmol/L or low-density lipoprotein-cholesterol >5.5 mmol/L, adjusted for age, ongoing lipid lowering therapy and presence of premature coronary artery disease) at increased risk for FH. When activated, the CDS will urge the physician to send an automatically generated referral to the local lipid clinic for further evaluation. To evaluate the effects of the CDS, all primary care clinics will be cluster randomized 1:1 to either CDS intervention or standard care in a Swedish region with almost 500,000 inhabitants. The primary endpoint will be the number of patients diagnosed with FH at 30 months. Resource use and long-term health consequences will be estimated to assess the cost-effectiveness of the intervention.

CONCLUSION

Despite increasing awareness of FH, the condition remains underdiagnosed and undertreated. The present study will investigate whether a CDS can increase the number of patients being diagnosed with FH.

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

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

Applying implementation science to improve care for familial hypercholesterolemia

PURPOSE OF REVIEW

Improving care of individuals with familial hypercholesteremia (FH) is reliant on the synthesis of evidence-based guidelines and their subsequent implementation into clinical care. This review describes implementation strategies, defined as methods to improve translation of evidence into FH care, that have been mapped to strategies from the Expert Recommendations for Implementing Change (ERIC) compilation.

RECENT FINDINGS

A search using the term 'familial hypercholesterolemia' returned 1350 articles from November 2018 to July 2021. Among these, there were 153 articles related to improving FH care; 1156 were excluded and the remaining 37 were mapped to the ERIC compilation of strategies: assess for readiness and identify barriers and facilitators [9], develop and organize quality monitoring systems [14], create new clinical teams [2], facilitate relay of clinical data to providers [4], and involve patients and family members [8]. There were only 8 of 37 studies that utilized an implementation science theory, model, or framework and two that explicitly addressed health disparities or equity.

SUMMARY

The mapping of the studies to implementation strategies from the ERIC compilation provides a framework for organizing current strategies to improve FH care. This study identifies potential areas for the development of implementation strategies to target unaddressed aspects of FH care.

Gaps in knowledge and practice for familial hypercholesterolemia among physicians caring for children in Saudi Arabia

OBJECTIVE

Familial hypercholesterolemia (FH) is an inherited genetic disorder that can lead to an early-onset cardiovascular disease if left untreated. Proper awareness of FH among physicians, particularly those taking care of children can facilitate early detection, diagnosis, and treatment. However, data regarding the knowledge, awareness, and practices of physicians in relation to FH are limited worldwide, so we aimed to explore this aspect.

MATERIALS AND METHODS

This cross-sectional study was conducted among physicians who would potentially treat pediatric patients at governmental hospitals and primary health care centers in the Qassim region of Saudi Arabia. A self-administered questionnaire consisting of 28 questions that assessed the physicians' knowledge, awareness, and practices related to FH was distributed among the participants.

RESULTS

In total, 148 physicians were recruited, including pediatricians, family physicians, and primary care physicians (males vs. females, 52.7% vs. 47.3%; most common age group, 31-40 years [44.6%]), of which 46.6% were familiar with FH. The total mean knowledge score was 5.54 (standard deviation, 3.12) out of 15 points, with 53.4%, 36.5%, and 10.1% of the participants showing inadequate, moderate, and adequate knowledge levels, respectively. The knowledge score was significantly better in the older age group (H=16.155; p=0.01) and among pediatric endocrinologists (H=16.155; p=0.001), while it was significantly lower among resident physicians (H=6.575; p=0.037) and those who had been practicing for 1-5 years (H=5.329; p=0.021).

CONCLUSIONS

The current study established significant gaps in the awareness, knowledge, and practices related to FH. Pediatric endocrinologists had the best levels of knowledge of FH. These findings emphasize the need for more extensive educational programs regarding the screening, diagnosis, and management of FH.

The microsomal triglyceride transfer protein inhibitor lomitapide improves vascular function in mice with obesity

OBJECTIVE

In this study, the effect of lomitapide, a microsomal triglyceride transfer protein inhibitor, on the cardiovascular function in obesity was investigated.

METHODS

Eight-week-old C57BL/6 mice were fed with high-fat diet for 12 weeks in the presence and absence of lomitapide. Lomitapide was administered by gavage (1 mg/kg/d) during the last 2 weeks of high-fat feeding. Body weight, blood glucose, body composition, and lipid profile were determined. Vascular function and endothelial function markers were studied in the aorta and mesenteric resistance arteries.

RESULTS

Lomitapide treatment reduced body weight in mice with obesity. Blood glucose, percentage of fat mass, total cholesterol, and low-density lipoprotein levels were significantly reduced, and the percentage of lean mass was significantly increased after lomitapide treatment. The vascular response to sodium nitroprusside in the aorta and mesenteric arteries was similar among groups. However, the vascular response to acetylcholine was improved in the treated group. This was associated with decreased levels of vascular endoplasmic reticulum stress, inflammation, and oxidative stress.

CONCLUSIONS

Treatment with lomitapide attenuated the increase in body weight in mice with obesity and restored the lipid profile and vascular function. These effects were accompanied by a decrease in inflammation and oxidative stress.

Splice correction therapies for familial hypercholesterolemic patients with low-density lipoprotein receptor mutations

PURPOSE OF REVIEW

Antisense oligomers (ASOs) have been available for decades: however, only recently have these molecules been applied clinically. This review aims to discuss the possible development of antisense-mediated splice correction therapies as precision medicines for familial hypercholesterolemic patients carrying mutations that compromise normal splicing of the low-density lipoprotein receptor (LDLR) gene transcript.

RECENT FINDINGS

Three antisense drugs are currently being assessed in ongoing clinical trials for dyslipidemias, aiming to lower the plasma concentrations of lipoproteins that lead to end-organ damage, principally coronary artery disease. Although a handful of drugs may be applicable to many patients with familial hypercholesterolemia (FH), mutation-specific personalised antisense drugs may be even more effective in selected patients. Currently, there is no therapy that effectively addresses mutations in the LDLR, the major cause of FH. Many mutations in the LDLR that disrupt normal pre-mRNA processing could be applicable to splice correction therapy to restore receptor activity.

SUMMARY

Precision medicine could provide long-term economic and social benefits if they can be implemented effectively and sustainably. Many mutations found in the LDLR gene could be amendable to therapeutic splice correction and we should consider developing a therapeutic ASO platform for these mutations.

Use of apheresis in the age of new therapies for familial hypercholesterolaemia

PURPOSE OF REVIEW

Lipoprotein apheresis has been first line therapy for homozygous familial hypercholesterolaemia (FH) and other severe and refractory forms of dyslpidaemia for over 40 years but the recent advent of novel and potent LDL-lowering compounds necessitates a reappraisal of its role.

RECENT FINDINGS

During the past decade a substantial amount of evidence has accumulated describing the effect of LDL-lowering with apheresis and conventional drug therapy upon the cardiovascular outcomes associated with homozygous and statin-refractory heterozygous FH. This has necessitated re-defining the target levels of LDL cholesterol needed to arrest progression of atherosclerosis in these situations. At the same time, evidence has accrued regarding the pathogenicity of raised levels of lipoprotein (a) and the promising role of apheresis in mitigating the adverse effects of the latter. The latest advance in treatment has been the introduction of three classes of novel and potent LDL-lowering compounds in the shape of inhibitors of Propertin convertase subtilisin kexin 9 (PCSK9), microsomal triglyceride transfer protein and angiopoietin-like 3.

SUMMARY

These recent developments raise the question of whether these compounds will be used as adjuvants to bolster lipoprotein apheresis in FH homozygotes or whether they will render it obsolete, as is already occurring with PCSK9 inhibitors in FH heterozygotes.

Familial Hypercholesterolemia: JACC Focus Seminar 4/4

Detecting familial hypercholesterolemia (FH) early and "normalizing" low-density lipoprotein (LDL) cholesterol values are the 2 pillars for effective cardiovascular disease prevention in FH. Combining lipid-lowering therapies targeting synergistic/complementary metabolic pathways makes this feasible, even among severe phenotypes. For LDL receptor-dependent treatments, PCSK9 remains the main target for adjunctive therapy to statins and ezetimibe through a variety of approaches. These include protein inhibition (adnectins), inhibition of translation at mRNA level (antisense oligonucleotides or small interfering RNA), and creation of loss-of-function mutations through base-pair editing. For patients with little LDL receptor function, LDL receptor-independent treatment targeting ANGPTL3 through monoclonal therapies are now available, or in the future, antisense/small interfering RNA-based approaches offer alternative approaches. Finally, first-in-human studies are ongoing, testing adenovirus-mediated gene therapy transducing healthy LDLR DNA in patients with HoFH. Further development of the CRISPR cas technology, which has shown promising results in vivo on introducing PCSK9 loss-of-function mutations, will move a single-dose, curative treatment for FH closer.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Familial Hypercholesterolaemia in the Malaysian Community: Prevalence, Under-Detection and Under-Treatment

AIM

Familial hypercholesterolaemia (FH) is the most common autosomal dominant lipid disorder, leading to severe hypercholesterolaemia. Early detection and treatment with lipid-lowering medications may reduce the risk of premature coronary artery disease in FH patients. However, there is scarcity of data on FH prevalence, detection rate, treatment and control with lipid-lowering therapy in the Malaysian community.

METHODS

Community participants (n=5130) were recruited from all states in Malaysia. Blood samples were collected for lipid profiles and glucose analyses. Personal and family medical histories were collected by means of assisted questionnaire. Physical examination for tendon xanthomata and premature corneal arcus were conducted on-site. FH were clinically screened using Dutch Lipid Clinic Network Criteria.

RESULTS

Out of 5130 recruited community participants, 55 patients were clinically categorised as potential (Definite and Probable) FH, making the prevalence FH among the community as 1:100. Based on current total population of Malaysia (32 million), the estimated number of FH patients in Malaysia is 320,000, while the detection rates are estimated as 0.5%. Lipid-lowering medications were prescribed to 54.5% and 30.5% of potential and possible FH patients, respectively, but none of them achieved the therapeutic LDL-c target.

CONCLUSION

Clinically diagnosed FH prevalence in Malaysian population is much higher than most of the populations in the world. At community level, FH patients are clinically under-detected, with majority of them not achieving target LDL-c level for high-risk patients. Therefore, public health measures are warranted for early detection and treatment, to enhance opportunities for premature CAD prevention.