Diagnosis and Treatment of Heterozygous Familial Hypercholesterolemia

Potentials of artificial intelligence in familial hypercholesterolemia: Advances in screening, diagnosis, and risk stratification for early intervention and treatment

Familial hypercholesterolemia (FH) poses a global health challenge due to high incidence rates and underdiagnosis, leading to increased risks of early-onset atherosclerosis and cardiovascular diseases. Early detection and treatment of FH is critical in reducing the risk of cardiovascular events and improving the long-term outcomes and quality of life for affected individuals and their families. Traditional therapeutic approaches revolve around lipid-lowering interventions, yet challenges persist, particularly in accurate and timely diagnosis. The current diagnostic landscape heavily relies on genetic testing of specific LDL-C metabolism genes, often limited to specialized centers. This constraint has led to the adoption of alternative clinical scores for FH diagnosis. However, the rapid advancements in artificial intelligence (AI) and machine learning (ML) present promising solutions to these diagnostic challenges. This review explores the intricacies of FH, highlighting the challenges that are encountered in the diagnosis and management of the disorder. The revolutionary potential of ML, particularly in large-scale population screening, is highlighted. Applications of ML in FH screening, diagnosis, and risk stratification are discussed, showcasing its ability to outperform traditional criteria. However, challenges and ethical considerations, including algorithmic stability, data quality, privacy, and consent issues, are crucial areas that require attention. The review concludes by emphasizing the significant promise of AI and ML in FH management while underscoring the need for ethical and practical vigilance to ensure responsible and effective integration into healthcare practices.

A Rapid and Scalable Multiplex PCR-Based Next-Generation Amplicon Sequencing Method for Familial Hypercholesterolemia Genetic Screening

BACKGROUND

Familial hypercholesterolemia (FH) is a frequently underdiagnosed genetic disorder characterized by elevated low-density lipoprotein (LDL) levels. Genetic testing of LDLR, APOB, and PCSK9 genes can identify variants in up to 80% of clinically diagnosed patients. However, limitations in time, scalability, and cost have hindered effective next-generation sequencing of these genes. Additionally, pharmacogenomic variants are associated with statin-induced adverse effects in FH patients. To address these challenges, we developed a multiplex primer-based amplicon sequencing approach for FH genetic testing.

METHODS

Multiplex primers were designed for the exons of the LDLR, APOB, and PCSK9 genes, as well as for pharmacogenomic variants rs4149056 (SLCO1B1:c.521T > A), rs2306283 (SLCO1B1:c.388A > G), and rs2231142 (ABCG2:c.421C > A). Analytical validation using samples with known pathogenic variants and clinical validation with 12 FH-suspected probands were conducted. Library preparation was based on a bead-based tagmentation method, and sequencing was conducted on the NovaSeq 6000 platform.

RESULTS

Our approach ensured no amplicon dropouts, with over 100× coverage on each amplicon. Known variants in 2 samples were successfully detected. Further, we identified one heterozygous LDLR (p.Glu228Ter) variant and 2 homozygous cases of LDLR (p.Lys294Ter) and LDLR (p.Ser177Leu) variants in patients. Pharmacogenomic analysis revealed that overall 3 patients may require reduced statin doses. Our approach offered reduced library preparation time (approximately 3 h), greater scalability, and lower costs (under $50) for FH genetic testing.

CONCLUSIONS

Our method effectively sequences LDLR, APOB, and PCSK9 genes including pharmacogenomic variants that will guide appropriate screening and statin dosing, thus increasing both efficiency and affordability.

Enhancing Familial Hypercholesterolemia Detection in South Korea: A Targeted Screening Approach Integrating National Program and Genetic Cascade Screening

BACKGROUND AND OBJECTIVES

Familial hypercholesterolemia (FH) increases the risk of premature cardiovascular disease through disrupted low-density lipoprotein cholesterol (LDL-C) metabolism. Although FH is a severe condition, it remains widely underdiagnosed, which can be attributed to barriers in genetic testing and a lack of awareness. This study aims to propose and evaluate a targeted screening program for FH in South Korea by integrating the General Health Screening Program (GHSP) with cascade genetic screening.

METHODS

The study included individuals with LDL-C levels ≥190 mg/dL identified during the 2021 GHSP (primary participants). Data on demographics, lifestyle, medical history, and family history were collected through questionnaires. Targeted next-generation sequencing was used to identify pathogenic mutations in the PCSK9, APOB, LDLRAP1, and LDLR genes associated with FH. Pathogenic mutations found in primary participants were confirmed in their relatives (secondary participants) using Sanger sequencing. Participant characteristics were analyzed based on the presence of pathogenic mutations.

RESULTS

Among 83 individuals with severe hypercholesterolemia identified through the GHSP, 7 primary participants (8.4%) carried pathogenic mutations in the LDLR and PCSK9 genes. In secondary participants, pathogenic mutations were identified in 61.1% of the relatives of 4 patients with pathogenic mutations. The prevalence of pathogenic mutations was significantly higher in primary participants compared to secondary participants.

CONCLUSIONS

Integrating community resources with FH screening can enhance the early detection and treatment of FH. By utilizing GHSP data and adding genetic screening, the proposed model provides a strategy to reduce the cardiovascular risks associated with FH, supporting its wider adoption at the national level.

The Growing Class of Novel RNAi Therapeutics

The clinical use of RNA interference (RNAi) molecular mechanisms has introduced a novel, growing class of RNA therapeutics capable of treating diseases by controlling target gene expression at the posttranscriptional level. With the newly approved nedosiran (Rivfloza), there are now six RNAi-based therapeutics approved by the United States Food and Drug Administration (FDA). Interestingly, five of the six FDA-approved small interfering RNA (siRNA) therapeutics [patisiran (Onpattro), lumasiran (Oxlumo), inclisiran (Leqvio), vutrisiran (Amvuttra), and nedosiran] were revealed to act on the 3'-untranslated regions of target mRNAs, instead of coding sequences, thereby following the common mechanistic action of genome-derived microRNAs (miRNA). Furthermore, three of the FDA-approved siRNA therapeutics [patisiran, givosiran (Givlaari), and nedosiran] induce target mRNA degradation or cleavage via near-complete rather than complete base-pair complementarity. These features along with previous findings confound the currently held characteristics to distinguish siRNAs and miRNAs or biosimilars, of which all converge in the RNAi regulatory pathway action. Herein, we discuss the RNAi mechanism of action and current criteria for distinguishing between miRNAs and siRNAs while summarizing the common and unique chemistry and molecular pharmacology of the six FDA-approved siRNA therapeutics. The term "RNAi" therapeutics, as used previously, provides a coherently unified nomenclature for broader RNAi forms as well as the growing number of therapeutic siRNAs and miRNAs or biosimilars that best aligns with current pharmacological nomenclature by mechanism of action. SIGNIFICANCE STATEMENT: The common and unique chemistry and molecular pharmacology of six FDA-approved siRNA therapeutics are summarized, in which nedosiran is newly approved. We point out rather a surprisingly mechanistic action as miRNAs for five siRNA therapeutics and discuss the differences and similarities between siRNAs and miRNAs that supports using a general and unified term "RNAi" therapeutics to align with current drug nomenclature criteria in pharmacology based on mechanism of action and embraces broader forms and growing number of novel RNAi therapeutics.

An evaluation of the cost-effectiveness of population genetic screening for familial hypercholesterolemia in US patients

BACKGROUND AND AIMS

Familial hypercholesterolemia is an underdiagnosed genetic metabolic condition limiting the clearance of low-density lipoprotein cholesterol and increasing lifetime risk of cardiovascular disease. Population genetic screening in unselected individuals could quickly identify cases of familial hypercholesterolemia and enable early prevention, but the economic impact of widespread screening on patients has not been studied.

METHODS

We assessed the cost-effectiveness of population genetic screening for familial hypercholesterolemia in 20 and 35-year-old adults in the United States from the perspective of patients. We developed a decision tree Markov hybrid model to examine diagnoses, cardiovascular disease, cardiac events, quality of life, and costs under population genetic screening compared to family-based cascade testing.

RESULTS

While population genetic screening increased diagnoses and reduced incidence of cardiovascular disease, population genetic screening was not cost-effective compared to cascade testing at current levels of willingness to pay. Lower genetic testing costs, combined screening with other genetic conditions, and support to maintain lipid-lowering therapy use over time could improve the cost-effectiveness of population genetic screening.

CONCLUSIONS

Future research is needed to examine how cost-sharing strategies may affect the cost-effectiveness of screening to patients and how families and providers experience the clinical and economic outcomes of population screening.

Subclinical Atherosclerosis to Guide Treatment in Dyslipidemia and Diabetes Mellitus

PURPOSE OF REVIEW

Dyslipidemia and type 2 diabetes mellitus are two common conditions that are associated with an increased risk of atherosclerotic cardiovascular disease (ASCVD). In this review, we aimed to provide an in-depth and contemporary review of non-invasive approaches to assess subclinical atherosclerotic burden, predict cardiovascular risk, and guide appropriate treatment strategies. We focused this paper on two main imaging modalities: coronary artery calcium (CAC) score and computed tomography coronary angiography.

RECENT FINDINGS

Recent longitudinal studies have provided stronger evidence on the relationship between increased CAC, thoracic aorta calcification, and risk of cardiovascular events among those with primary hypercholesterolemia, highlighting the beneficial role of statin therapy. Interestingly, resilient profiles of individuals not exhibiting atherosclerosis despite dyslipidemia have been described. Non-conventional markers of dyslipidemia have also been associated with increased subclinical atherosclerosis presence and burden, highlighting the contribution of apolipoprotein B-100 (apoB)-rich lipoprotein particles, such as remnant cholesterol and lipoprotein(a), to the residual risk of individuals on-target for low-density lipoprotein cholesterol (LDL-C) goals. Regarding type 2 diabetes mellitus, variability in atherosclerotic burden has also been found, and CAC testing has shown significant predictive value in stratifying cardiovascular risk. Non-invasive assessment of subclinical atherosclerosis can help reveal the continuum of ASCVD risk in those with dyslipidemia and diabetes mellitus and can inform personalized strategies for cardiovascular disease prevention in the primary prevention setting.

Management of lipid variables in primary cardiovascular prevention: A position paper from the Heart, Vessels and Metabolism Group of the French Society of Cardiology

Low-density lipoprotein cholesterol has been established as a powerful cardiovascular risk factor; its reduction provides a clinical benefit in primary cardiovascular prevention, irrespective of the characteristics of the patients treated. It is useful to tailor low-density lipoprotein cholesterol targets according to the magnitude of cardiovascular risk (low, high or very high) in order to reduce the cardiovascular risk as fully as possible. In order to provide a uniform approach, it is necessary to propose recommendations for good practice, defining strategies for reducing low-density lipoprotein cholesterol. It is also necessary to know their merits, to analyse their practical limits and to propose adaptations, taking into account limitations and national specifics. This position paper aims to analyse the contribution and limits, as well as the adaptation to French practice, of 2019 and 2021 European Society of Cardiology recommendations for the management of lipid variables and cardiovascular prevention.

Obesity and atherosclerotic cardiovascular disease in adults with heterozygous familial hypercholesterolemia: An analysis from HELLAS-FH registry

BACKGROUND

Familial hypercholesterolemia (FH) and obesity are well-established risk factors of atherosclerotic cardiovascular disease (ASCVD). Despite high prevalence, their joint association with ASCVD remains largely unknown.

OBJECTIVE

To investigate the association of obesity with prevalent ASCVD in individuals with heterozygous FH (HeFH) enrolled in the Hellenic Familial Hypercholesterolemia Registry (HELLAS-FH).

METHODS

FH diagnosis was based on Dutch Lipid Clinic Network (DLCN) criteria. Adults with at least possible FH diagnosis (DLCN score ≥3) and available body mass index (BMI) values were included. Homozygous FH individuals were excluded.

RESULTS

1655 HeFH adults (mean age 51.0 ± 14.4 years, 48.6% female) were included; 378 (22.8%) and 430 (26.0%) were diagnosed with probable and definite FH, respectively. Furthermore, 371 participants (22.4%) had obesity and 761 (46.0%) were overweight. Prevalence of ASCVD risk factors increased progressively with BMI. Prevalence of coronary artery disease (CAD) was 23.4% (3.2% for stroke and 2.7% for peripheral artery disease [PAD]), and increased progressively across BMI groups. After adjusting for traditional ASCVD risk factors and lipid-lowering medication, individuals with obesity had higher odds of established CAD (OR: 1.54, 95% CI: 1.04-2.27, p = 0.036) as well as premature CAD (OR: 1.74, 95% CI: 1.17-2.60, p = 0.009) compared with those with normal BMI. No association was found with stroke or PAD.

CONCLUSIONS

Over half of adults with HeFH have overweight or obesity. Obesity was independently associated with increased prevalence of CAD in this population.

Conducting Drug Treatment Trials in Children: Opportunities and Challenges

Children were often referred to as "therapeutic orphans" in the past due to different reasons such as ethical, regulatory, economic, scientific, etc., ones. They were exposed to avoidable risks while missing out on therapeutic advances. Pediatric patients have suffered from a lack of scientific and regulatory standards (e.g., proper drug testing, authorization of medicines for their use, etc.), although the pharmaceutical legislative framework, which ensures the high standards of safety, quality, and efficacy of medicinal products for use in adults, was developed primarily in response to past "drug disasters," mainly involving children. The adoption of pediatric regulatory initiatives first in the USA and then in Europe and other countries and regions has significantly changed the worldwide frameworks and permanently changed pediatric drug research and development. This article tries to give various perspectives with historical context, a review of the different challenges and opportunities as well as important stakeholders in pediatric drug development. The pediatric trial networks are probably the most important stakeholder that enables efficient patient recruitment, access to better resource utilization, and global collaboration of different stakeholders necessary for performing quality and well-designed clinical trials.

Family cascade screening for equitable identification of familial hypercholesterolemia: study protocol for a hybrid effectiveness-implementation type III randomized controlled trial

BACKGROUND

Familial hypercholesterolemia (FH) is a heritable disorder affecting 1.3 million individuals in the USA. Eighty percent of people with FH are undiagnosed, particularly minoritized populations including Black or African American people, Asian or Asian American people, and women across racial groups. Family cascade screening is an evidence-based practice that can increase diagnosis and improve health outcomes but is rarely implemented in routine practice, representing an important care gap. In pilot work, we leveraged best practices from behavioral economics and implementation science-including mixed-methods contextual inquiry with clinicians, patients, and health system constituents-to co-design two patient-facing implementation strategies to address this care gap: (a) an automated health system-mediated strategy and (b) a nonprofit foundation-mediated strategy with contact from a foundation-employed care navigator. This trial will test the comparative effectiveness of these strategies on completion of cascade screening for relatives of individuals with FH, centering equitable reach.

METHODS

We will conduct a hybrid effectiveness-implementation type III randomized controlled trial testing the comparative effectiveness of two strategies for implementing cascade screening with 220 individuals with FH (i.e., probands) per arm identified from a large northeastern health system. The primary implementation outcome is reach, or the proportion of probands with at least one first-degree biological relative (parent, sibling, child) in the USA who is screened for FH through the study. Our secondary implementation outcomes include the number of relatives screened and the number of relatives meeting the American Heart Association criteria for FH. Our secondary clinical effectiveness outcome is post-trial proband cholesterol level. We will also use mixed methods to identify implementation strategy mechanisms for implementation strategy effectiveness while centering equity.

DISCUSSION

We will test two patient-facing implementation strategies harnessing insights from behavioral economics that were developed collaboratively with constituents. This trial will improve our understanding of how to implement evidence-based cascade screening for FH, which implementation strategies work, for whom, and why. Learnings from this trial can be used to equitably scale cascade screening programs for FH nationally and inform cascade screening implementation efforts for other genetic disorders.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05750667. Registered 15 February 2023-retrospectively registered, https://clinicaltrials.gov/study/NCT05750667 .

Sex differences in trends and in-hospital outcomes of acute myocardial infarction in patients with familial hypercholesterolemia: insights from a large national database

BACKGROUND

Sex differences in clinical outcomes following acute myocardial infarction (AMI) are well known. However, data on sex differences among patients with familial hypercholesterolemia (FH) are limited. We aimed to explore sex differences in outcomes of AMI among patients with FH from a national administrative dataset.

RESEARCH DESIGN AND METHODS

We utilized the National Inpatient Sample to identify admissions with a primary diagnosis of AMI and a secondary diagnosis of FH. Our primary outcome of interest was in-hospital mortality; secondary outcomes were performance of percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG), respiratory complications, use of inotropes, use of mechanical circulatory support (MCS), bleeding complications, transfusion and facility discharge. We adjusted for demographics (model A), comorbidities (model B), and intervention (model C).

RESULTS

Between October 2016 and December 2020, 5,714,993 admissions with a primary diagnosis of AMI were identified, of which 3,035 (0.05%) had a secondary diagnosis of FH. In-hospital mortality did not differ between men and women (Model C, adjusted OR = 0.85; 95% CI 0.28-2.60, p = 0.773). There was no sex difference in the secondary outcomes.

CONCLUSION

Despite generally being older and having more comorbidities, women with FH fair equally with men with FH in terms of mortality during AMI admission.

Efficacy and safety of bempedoic acid in patients with heterozygous familial hypercholesterolemia: analysis of pooled patient-level data from phase 3 clinical trials

BACKGROUND

Patients with heterozygous familial hypercholesterolemia (HeFH) often cannot reach guideline-recommended low-density lipoprotein cholesterol (LDL-C) goals despite multidrug therapy.

OBJECTIVE

To evaluate the efficacy and safety of bempedoic acid as an add-on therapy for lowering LDL-C in patients with HeFH.

METHODS

Pooled data from two 52-week phase 3 clinical trials of patients with atherosclerotic cardiovascular disease and/or HeFH receiving maximally tolerated statin therapy (randomized 2:1 to bempedoic acid or placebo) were analyzed by HeFH status. Endpoints included changes from baseline to week 12 (and up to week 52) in LDL-C and other lipid parameters, achievement of LDL-C goals, and safety.

RESULTS

A total of 217 (bempedoic acid, 146; placebo, 71) patients with HeFH and 2,792 (bempedoic acid, 1,864; placebo, 928) without HeFH were included (mean baseline LDL-C, 172.8 mg/dL and 102.6 mg/dL, respectively). Bempedoic acid significantly lowered LDL-C at week 12 vs. placebo regardless of HeFH status (with HeFH, -21.2%; without HeFH, -18.2% [both P<0.0001]). Bempedoic acid significantly reduced other lipid parameters and high-sensitivity C-reactive protein vs. placebo regardless of HeFH status (all P≤0.01). Among patients with HeFH treated with bempedoic acid, 32% and 27% achieved LDL-C <100 mg/dL at weeks 12 and 52, respectively. Overall treatment-emergent adverse event incidence was comparable across all four groups (74.7-77.5%).

CONCLUSION

Bempedoic acid significantly lowered LDL-C levels vs. placebo and was generally well tolerated in all patients, with no new safety findings in patients with HeFH, despite more intensive lipid-lowering therapy in patients with vs. without HeFH.

Measuring Costs of Cardiovascular Disease Prevention for Patients with Familial Hypercholesterolemia in Administrative Claims Data

INTRODUCTION

Familial hypercholesterolemia is a common genetic condition that significantly increases an individual's risk of cardiovascular events such as heart attack, stroke, and cardiac death and is a candidate for population-wide screening programs. Economic analyses of strategies to identify and treat familial hypercholesterolemia are limited by a lack of real-world cost estimates for screening services and medications for reducing cardiovascular risk in this population.

METHODS

We estimated the cost of lipid panel testing in patients with hyperlipidemia and the cost of statins, ezetimibe, and PCKS9 inhibitors in patients with familial hypercholesterolemia from a commercial claims database and report costs and charges per panel and prescription by days' supply.

RESULTS

The mean cost for a 90-day supply for statins was $183.33, 2.3 times the mean cost for a 30-day supply at $79.35. PCSK9 inhibitors generated the highest mean costs among medications used by patients with familial hypercholesterolemia.

CONCLUSIONS

Lipid testing and lipid-lowering medications for cardiovascular disease prevention generate substantial real-world costs which can be used to improve cost-effectiveness models of familial hypercholesterolemia screening and care management.

Is there a role for earlier use of combination therapy?

As the global population ages and cardiovascular risk factors rise, we can expect a continued increase in atherosclerotic disease. Low-density lipoprotein cholesterol (LDL-C) reduction is a cornerstone of cardiovascular risk reduction with strong, causal evidence indicating that the greatest benefit is derived from early and large decreases in LDL-C. Despite the adoption of statins as the backbone of lipid-therapy regimens, numerous studies and registry analyses reveal our collective inability to achieve LDL-C goals in high-risk patients. Combination therapy with ezetimibe has been shown to result in statistically significant decreases in LDL-C level, atheroma volume, and cardiovascular adverse event rates. A major barrier to implementing an upfront combination therapy approach is the perceived side effects from therapeutic agents although multiple studies show that a therapeutic patient-physician relationship could overcome this issue. Novel agents such as PCSK-9 inhibitors, bempedoic acid, and inclisiran have the potential to achieve similar outcomes although additional research is needed regarding the cost effectiveness of these approaches. Despite these hurdles, there is a role for the newer agents early in the disease course of high-risk patients such as those with markedly elevated LDL-C >190 mg/dL and FH. The implementation of upfront combination therapy, especially in high-risk patients, will decrease clinical inertia while allowing for earlier consideration of newer, effective agents to decrease cardiovascular burden.

Acute myocardial infarction in an untreated patient with acute myeloid leukemia

Key Clinical Message

Acute leukemia, particularly AML, is closely associated with thrombotic events, driven by complex factors like coagulation system changes, endothelial dysfunction, and leukemic cell interactions with the vascular system. Certain chemotherapy drugs can exacerbate the prothrombotic state. Understanding these dynamics is crucial for effective thromboprophylaxis in carefully selected patients with leukemia.

Abstract

Thrombosis is a significant complication of acute leukemia. Thrombotic events mostly occur at diagnosis or during induction therapy. Here we report the occurrence of myocardial infarction (MI) before initiation of therapy, in a patient with acute myeloid leukemia not otherwise specified (AML NOS) who had no other significant risk factors for coronary artery disease. The occurrence of MI in this patient limited the choice of induction therapy and resulted in mortality. We discuss the pathogenesis and risk factors associated with increased thrombosis in AML and advocate for risk-adapted thromboprophylaxis in this patient population.

LDLR gene rearrangements in Czech FH patients likely arise from one mutational event

BACKGROUND

Large deletions and duplications within the low-density lipoprotein receptor (LDLR) gene make up approximately 10% of LDLR pathogenic variants found in Czech patients with familial hypercholesterolemia. The goal of this study was to test the hypothesis that all probands with each rearrangement share identical breakpoints inherited from a common ancestor and to determine the role of Alu repetitive elements in the generation of these rearrangements.

METHODS

The breakpoint sequence was determined by PCR amplification and Sanger sequencing. To confirm the breakpoint position, an NGS analysis was performed. Haplotype analysis of common LDLR variants was performed using PCR and Sanger sequencing.

RESULTS

The breakpoints of 8 rearrangements within the LDLR gene were analysed, including the four most common LDLR rearrangements in the Czech population (number of probands ranging from 8 to 28), and four less common rearrangements (1-4 probands). Probands with a specific rearrangement shared identical breakpoint positions and haplotypes associated with the rearrangement, suggesting a shared origin from a common ancestor. All breakpoints except for one were located inside an Alu element. In 6 out of 8 breakpoints, there was high homology (≥ 70%) between the two Alu repeats in which the break occurred.

CONCLUSIONS

The most common rearrangements of the LDLR gene in the Czech population likely arose from one mutational event. Alu elements likely played a role in the generation of the majority of rearrangements inside the LDLR gene.

The genetics of autosomal dominant familial hypercholesterolemia

ABSTRACT

Familial hypercholesterolemia (FH) is one of the most common genetic conditions. Affected individuals are unable to metabolize cholesterol due to inherited changes in the low-density lipoprotein (LDL) receptor, which impairs the ability to metabolize cholesterol, resulting in extremely high levels of cholesterol that leads to premature coronary artery disease. Autosomal dominant FH is caused by variants in several genes, which may present as heterozygous FH (less severe) or homozygous FH (more severe). Clinical diagnosis may be more likely when there is a family history of two or more first-degree relatives with total and LDL-cholesterol (LDL-C) level elevations, a child is identified, or the affected individual or close relatives have tendon xanthomas and/or progressive atherosclerosis. This article provides an overview of autosomal dominant FH, including disease prevalence, clinical diagnostic criteria, genetic variants, diagnostic testing, pathognomonic findings, and treatment options. It also shares a brief case, which highlights challenges associated with genetic test interpretation and the importance of including experienced providers in the diagnosis and treatment of this underdiagnosed and often untreated or undertreated genetic condition.

Unveiling Familial Hypercholesterolemia-Review, Cardiovascular Complications, Lipid-Lowering Treatment and Its Efficacy

Familial hypercholesterolemia (FH) is a genetic disorder primarily transmitted in an autosomal-dominant manner. We distinguish two main forms of FH, which differ in the severity of the disease, namely homozygous familial hypercholesterolemia (HoFH) and heterozygous familial hypercholesterolemia (HeFH). The characteristic feature of this disease is a high concentration of low-density lipoprotein cholesterol (LDL-C) in the blood. However, the level may significantly vary between the two mentioned types of FH, and it is decidedly higher in HoFH. A chronically elevated concentration of LDL-C in the plasma leads to the occurrence of certain abnormalities, such as xanthomas in the tendons and skin, as well as corneal arcus. Nevertheless, a significantly more severe phenomenon is leading to the premature onset of cardiovascular disease (CVD) and its clinical implications, such as cardiac events, stroke or vascular dementia, even at a relatively young age. Due to the danger posed by this medical condition, we have investigated how both non-pharmacological and selected pharmacological treatment impact the course of FH, thereby reducing or postponing the risk of clinical manifestations of CVD. The primary objective of this review is to provide a comprehensive summary of the current understanding of FH, the effectiveness of lipid-lowering therapy in FH and to explain the anatomopathological correlation between FH and premature CVD development, with its complications.

PCSK9 inhibitor use during pregnancy in a case of familial hypercholesterolemia complicated with coronary artery disease

Limited data have been reported on the use of proprotein convertase subtilisin/kexin type 9 (PCSK 9) inhibitors during pregnancy in women with familial hypercholesterolemia (FH). Here, we present the first case of initiating evolocumab (PCSK9 inhibitor) in a compound heterozygous FH mother. The patient was a 34-year-old primipara with severe dyslipidemia and a history of coronary artery bypass surgery. An elevated low-density lipoprotein cholesterol (LDL-C) level of 420 mg/dL was detected in the first trimester and persistently increased throughout pregnancy. Evolocumab was administered at 31 and 35 weeks of gestation, showing a positive effect on stabilizing LDL-C levels. Planned delivery with labor analgesia was performed at 38 + 4 weeks. Both the mother and infant were discharged without any notable complications. Hence, evolocumab, an IgG2 monochromatic antibody with little placental permeability, may be an alternative medication with limited influence on infants. Further studies are needed to assess the safety of evolocumab administration during pregnancy.

Antihyperlipidemic Treatment Options in Statin Resistance and Intolerance

Cardiovascular disease is the global leading cause of death and hypercholesterolemia is implicated as one of its top contributors. Moreover, there is growing recognition that lower low-density lipoprotein cholesterol levels offer greater protection against cardiovascular disease. Statins are the first-line lipid-lowering agents for both primary and secondary prevention of cardiovascular disease in patients with hypercholesterolemia. However, statin resistance and intolerance lead to undertreatment in patients who would likely derive the most benefit from antihyperlipidemic drugs. Several non-statin therapies are increasingly prescribed to such patients, most commonly ezetimibe and the PCSK9 monoclonal antibodies, but numerous other options have been developed in recent years and investigations into new therapies are ongoing. The use of these non-statin therapies requires the clinician to take a highly personalized approach to cholesterol reduction in complex patients. In this review, we describe current non-statin options for statin-resistant and statin-intolerant patients in addition to areas of active research.

Targeting the Liver with Nucleic Acid Therapeutics for the Treatment of Systemic Diseases of Liver Origin

Systemic diseases of liver origin (SDLO) are complex diseases in multiple organ systems, such as cardiovascular, musculoskeletal, endocrine, renal, respiratory, and sensory organ systems, caused by irregular liver metabolism and production of functional factors. Examples of such diseases discussed in this article include primary hyperoxaluria, familial hypercholesterolemia, acute hepatic porphyria, hereditary transthyretin amyloidosis, hemophilia, atherosclerotic cardiovascular diseases, α-1 antitrypsin deficiency-associated liver disease, and complement-mediated diseases. Nucleic acid therapeutics use nucleic acids and related compounds as therapeutic agents to alter gene expression for therapeutic purposes. The two most promising, fastest-growing classes of nucleic acid therapeutics are antisense oligonucleotides (ASOs) and small interfering RNAs (siRNAs). For each listed SDLO disease, this article discusses epidemiology, symptoms, genetic causes, current treatment options, and advantages and disadvantages of nucleic acid therapeutics by either ASO or siRNA drugs approved or under development. Furthermore, challenges and future perspectives on adverse drug reactions and toxicity of ASO and siRNA drugs for the treatment of SDLO diseases are also discussed. In summary, this review article will highlight the clinical advantages of nucleic acid therapeutics in targeting the liver for the treatment of SDLO diseases. SIGNIFICANCE STATEMENT: Systemic diseases of liver origin (SDLO) contain rare and common complex diseases caused by irregular functions of the liver. Nucleic acid therapeutics have shown promising clinical advantages to treat SDLO. This article aims to provide the most updated information on targeting the liver with antisense oligonucleotides and small interfering RNA drugs. The generated knowledge may stimulate further investigations in this growing field of new therapeutic entities for the treatment of SDLO, which currently have no or limited options for treatment.

Identification and functional characterization of two rare LDLR stop gain variants (p.C231* and p.R744*) in Saudi familial hypercholesterolemia patients

BACKGROUND

Familial hypercholesterolemia (FH) is a globally underdiagnosed inherited metabolic disorder. Owing to limited published data from Arab world, this study was conducted with the aim of identifying the genetic and molecular basis of FH in highly consanguineous Saudi population.

METHODS

We performed clinical screening, biochemical profiling, whole exome sequencing and variant segregation analysis of two Saudi FH families. Additionally, 500 normolipic individuals were screened to ensure the absence of FH variant in general Saudi population. Functional characterization of FH variants on secondary structure characteristics of RNA and protein molecules was performed using different bioinformatics modelling approaches.

RESULTS

WES analysis identified two independent rare LDLR gene stop gain variants (p.C231* and p.R744*) consistent to the clinical presentation of FH patients from two different families. RNAfold analysis has shown that both variants were predicted to disturb the free energy dynamics of LDLR mRNA molecule and destabilize its folding pattern and function. PSIPRED based structural modelling analysis has suggested that both variants bring drastic changes disturbing the secondary structural elements of LDLR molecule. The p.C231* and p.R744* variants are responsible for partial or no protein product, thus they are class 1 variants causing loss of function (LoF) LDLR variants.

CONCLUSIONS

This study highlights the effectiveness of the WES, sanger sequencing, and computational analysis in expanding FH variant spectrum in culturally distinct populations like Saudi Arabia. Genetic testing of FH patients is very essential in better clinical diagnosis, screening, treatment, and management and prevention of cardiovascular disease burden in the society.

Facilitating family communication of familial hypercholesterolemia genetic risk: Assessing engagement with innovative chatbot technology from the IMPACT-FH study

Objective

To assess use of two web-based conversational agents, the Family Sharing Chatbot (FSC) and One Month Chatbot (OMC), by individuals with familial hypercholesterolemia (FH).

Methods

FSC and OMC were sent using an opt-out methodology to a cohort of individuals receiving a FH genetic result. Data from 7/1/2021 through 5/12/2022 was obtained from the electronic health record and the chatbots' HIPAA-secure web portal.

Results

Of 175 subjects, 21 (12%) opted out of the chatbots. Older individuals were more likely to opt out. Most (91/154, 59%) preferred receiving chatbots via the patient EHR portal. Seventy-five individuals (49%) clicked the FSC link, 62 (40%) interacted, and 36 (23%) shared a chatbot about their FH result with at least one relative. Ninety-two of the subjects received OMC, 22 (23%) clicked the link and 20 (21%) interacted. Individuals who shared were majority female and younger on average than the overall cohort. Reminders tended to increase engagement.

Conclusion

Results demonstrate characteristics relevant to chatbot engagement. Individuals may be more inclined to receive chatbots if integrated within the patient EHR portal. Frequent reminders can potentially improve chatbot utilization.

Innovation

FSC and OMC employ innovative digital health technology that can facilitate family communication about hereditary conditions.

Refinement of the diagnostic approach for the identification of children and adolescents affected by familial hypercholesterolemia: Evidence from the LIPIGEN study

BACKGROUND AND AIMS

We aimed to describe the limitations of familiar hypercholesterolemia (FH) diagnosis in childhood based on the presence of the typical features of FH, such as physical sings of cholesterol accumulation and personal or family history of premature cardiovascular disease or hypercholesterolemia, comparing their prevalence in the adult and paediatric FH population, and to illustrate how additional information can lead to a more effective diagnosis of FH at a younger age.

METHODS

From the Italian LIPIGEN cohort, we selected 1188 (≥18 years) and 708 (<18 years) genetically-confirmed heterozygous FH, with no missing personal FH features. The prevalence of personal and familial FH features was compared between the two groups. For a sub-group of the paediatric cohort (N = 374), data about premature coronary heart disease (CHD) in second-degree family members were also included in the evaluation.

RESULTS

The lower prevalence of typical FH features in children/adolescents vs adults was confirmed: the prevalence of tendon xanthoma was 2.1% vs 13.1%, and arcus cornealis was present in 1.6% vs 11.2% of the cohorts, respectively. No children presented clinical history of premature CHD or cerebral/peripheral vascular disease compared to 8.8% and 5.6% of adults, respectively. The prevalence of premature CHD in first-degree relatives was significantly higher in adults compared to children/adolescents (38.9% vs 19.7%). In the sub-cohort analysis, a premature CHD event in parents was reported in 63 out of 374 subjects (16.8%), but the percentage increased to 54.0% extending the evaluation also to second-degree relatives.

CONCLUSIONS

In children, the typical FH features are clearly less informative than in adults. A more thorough data collection, adding information about second-degree relatives, could improve the diagnosis of FH at younger age.

Longer-Term Efficacy and Safety of Evinacumab in Patients With Refractory Hypercholesterolemia

Importance

Patients with refractory hypercholesterolemia who do not achieve their guideline-defined low-density lipoprotein cholesterol (LDL-C) thresholds despite treatment with maximally tolerated combinations of lipid-lowering therapies (LLTs) have an increased risk of atherosclerotic cardiovascular disease (ASCVD).

Objective

To evaluate longer-term efficacy and safety of evinacumab in patients with refractory hypercholesterolemia.

Design, Setting, and Participants

This randomized clinical trial included a 2-week screening period followed by a 16-week double-blind treatment period (DBTP) for subcutaneous regimens (evinacumab, 450 mg, once weekly [QW]; evinacumab, 300 mg, QW; evinacumab, 300 mg, every 2 weeks; or placebo QW) or a 24-week DBTP for intravenous regimens (evinacumab, 15 mg/kg, every 4 weeks [Q4W]; evinacumab, 5 mg/kg, Q4W; or placebo Q4W); a 48-week open-label treatment period (OLTP) for intravenous treatment only; and a 24-week follow-up period. Patients from 85 sites across 20 countries were recruited for the study; patients with primary hypercholesterolemia (defined as heterozygous familial hypercholesterolemia or established clinical ASCVD without familial hypercholesterolemia) who entered the 48-week OLTP were included. In addition, the patients' hypercholesterolemia was refractory to maximally tolerated LLTs.

Interventions

All patients entering the OLTP received evinacumab, 15 mg/kg, intravenously Q4W.

Main Outcomes and Measures

Efficacy outcomes included change in LDL-C level and other lipid/lipoprotein parameters from baseline to week 72 (end of the OLTP). Safety outcomes included assessment of treatment-emergent adverse events (TEAEs).

Results

A total of 96 patients (mean [SD] age, 54.4 [11.3] years; 52 female [54.2%]) entered the OLTP, of whom 88 (91.7%) completed the OLTP. Mean (SD) baseline LDL-C level was 145.9 (55.2) mg/dL. At week 72, evinacumab, 15 mg/kg, reduced mean (SD) LDL-C level from baseline by 45.5% (28.7%) in the overall cohort. Evinacumab, 15 mg/kg, reduced mean (SD) apolipoprotein B (38.0% [22.1%]), non-high density lipoprotein cholesterol (48.4% [23.2%]), total cholesterol (42.6% [17.5%]), and median (IQR) fasting triglyceride (57.2% [65.4%-44.4%]) levels at week 72 from baseline in the overall cohort. TEAEs occurred in 78 of 96 patients (81.3%). Serious TEAEs occurred in 9 of 96 patients (9.4%); all were considered unrelated to study treatment.

Conclusions and Relevance

In patients with refractory hypercholesterolemia, evinacumab provided sustained reductions in LDL-C level and was generally well tolerated.

Trial Registration

ClinicalTrials.gov Identifier: NCT03175367.

Familial Hypercholesterolemia: From Clinical Suspicion to Novel Treatments

Familial hypercholesterolemia (FH) is the most common monogenic disorder in humans. It affects millions of people globally, increasing the risk of developing cardiovascular disease (CVD) at a younger age due to elevated levels of low-density lipoprotein cholesterol (LDL-C) from birth. While effective traditional and novel treatments are available, the most significant challenge with FH is the lack of timely diagnosis. As a result, many patients remain undertreated leading to an increased risk of CVD. To mitigate risk, initiating early and aggressive LDL-C-lowering therapies is recommended. Moreover, given its autosomal dominant inheritance patterns, it is also recommended to perform cascade lipid and/or genetic testing of all first-degree relatives. This review highlights the importance of early FH diagnosis and available treatment options. Greater awareness and improved screening efforts can help diagnose and treat more individuals, ultimately reducing the CVD risk associated with FH.

Domino Liver Transplantation for Unresectable Colon Cancer Liver Metastasis From a Donor With Heterozygous Familial Hyperlipidemia: A Case Report

Liver transplantation (LT) is a potential curative treatment for unresectable colorectal cancer liver metastasis (CRLM). Familial hypercholesterolemia (FH) is an inherited condition characterized by elevated low-density lipoprotein cholesterol (LDL-C) levels. Liver transplantation is offered for selected cases, and an explanted liver can be used as a domino graft. We report the first report of domino LT for unresectable CRLM using a liver from a patient with heterozygous FH. The domino donor was a 30-year-old female with a history of heterozygous FH. She had failed medical therapies for FH, including plasmapheresis; therefore, she underwent living donor LT as a treatment for FH. The explanted liver was transplanted to the domino recipient. She has been doing well with normal LDL-C levels. The domino recipient was a 44-year-old female with a history of stage 4 sigmoid cancer with liver metastases, for which she underwent laparoscopic sigmoid colectomy and right hepatectomy. She developed unresectable lesions in the remnant left lobe, which were controlled well with chemotherapy; therefore, she underwent domino LT. She is doing well without recurrence at the 31-month follow-up. Domino LT from a donor with heterozygous FH is feasible for strictly selected patients with unresectable CRLM.

A Pharmacologic Update: New Treatments for Patients with Cardiovascular Disease

Pharmacologic agents are a key part of the medical armamentarium aimed at reducing the significant morbidity and mortality caused by cardiovascular disease (CVD). In recent years, the landscape of CVD treatment has evolved with the development of new medication classes and the repurposing of existing medications for new indications. This article provides nurses with a pharmacologic update on new and emerging therapies for the treatment of hypertrophic cardiomyopathy, familial hypercholesterolemia, and heart failure. The authors review clinical indications, pharmacology, practical considerations for the safe and appropriate use of these medications, and implications for nurses.

Translating Evidence-based Approaches into optimal Care for individuals at High-risk of ASCVD: Pilot testing of case-based e-learning modules and design of the TEACH-ASCVD study

BACKGROUND

Atherosclerotic cardiovascular disease (ASCVD) remains the leading cause of death in the United States. Case-based learning using electronic delivery of the modules can educate clinicians and improve translation of evidence-based guidelines into practice for high-risk ASCVD patients.

OBJECTIVE

To develop and optimize module design, content, and usability of e-learning modules to teach clinicians evidence-based management in accordance with multi-society guidelines for high-risk ASCVD patients that will be implemented and evaluated in U.S. health systems in the TEACH-ASCVD study.

METHODS

Seven e-learning modules were created by a committee of lipid experts. Focus groups were conducted with lipid experts to elicit feedback on case content followed by interviews with a target audience of clinicians to assess usability of the online module platform. Responses from both groups were evaluated, and appropriate changes were made to improve the e-learning modules. Design of the TEACH-ASCVD study is presented.

RESULTS

Feedback regarding case content by lipid experts included providing more detailed patient histories, clarifying various diagnostic criteria, and emphasizing clinical best practices based on evidence-based guidelines. The target audience clinician group reported an agreeable experience with the e-learning modules but noted a discordance between the evidence-based guidelines and clinical decision-making in their own practices. Participants felt the modules would help educate clinicians in managing high-risk ASCVD patients.

CONCLUSION

Clinicians must be informed of best practices as the field of lipidology continues to evolve. E-learning modules provide a concise, valuable, and accessible mechanism for educating clinicians regarding changes in the field to deliver the best patient care.

Barriers and shortcomings in access to cardiovascular management and prevention for familial hypercholesterolemia during the COVID-19 pandemic

Familial hypercholesterolemia (FH) is a hereditary condition caused by mutations in the lipid pathway. The goal in managing FH is to reduce circulating low-density lipoprotein cholesterol and, therefore, reduce the risk of developing atherosclerotic cardiovascular disease (ASCVD). Because FH patients were considered high risk groups due to an increased susceptible for contracting COVID-19 infection, we hypothesized whether the effects of the pandemic hindered access to cardiovascular care. In this review, we conducted a literature search in databases Pubmed/Medline and ScienceDirect. We included a comprehensive analysis of findings from articles in English related and summarized the effects of the pandemic on cardiovascular care through direct and indirect effects. During the COVID-19 pandemic, FH patients presented with worse outcomes and prognosis, especially those that have suffered from early ASCVD. This caused avoidance in seeking care due to fear of transmission. The pandemic severely impacted consultations with lipidologists and cardiologists, causing a decline in lipid profile evaluations. Low socioeconomic communities and ethnic minorities were hit the hardest with job displacements and lacked healthcare coverage respectively, leading to treatment nonadherence. Lock-down restrictions promoted sedentary lifestyles and intake of fatty meals, but it is unclear whether these factors attenuated cardiovascular risk in FH. To prevent early atherogenesis in FH patients, universal screening programs, telemedicine, and lifestyle interventions are important recommendations that could improve outcomes in FH patients. However, the need to research in depth on the disproportionate impact within different subgroups should be the forefront of FH research.

Bias amplification of unobserved confounding in pharmacoepidemiological studies using indication-based sampling

PURPOSE

Estimating causal effects in observational pharmacoepidemiology is a challenging task, as it is often plagued by confounding by indication. Restricting the sample to those with an indication for drug use is a commonly performed procedure; indication-based sampling ensures that the exposed and unexposed are exchangeable on the indication-limiting the potential for confounding by indication. However, indication-based sampling has received little scrutiny, despite the hazards of exposure-related covariate control.

METHODS

Using simulations of varying levels of confounding and applied examples we describe bias amplification under indication-based sampling.

RESULTS

We demonstrate that indication-based sampling in the presence of unobserved confounding can give rise to bias amplification, a self-inflicted phenomenon where one inflates pre-existing bias through inappropriate covariate control. Additionally, we show that indication-based sampling generally leads to a greater net bias than alternative approaches, such as regression adjustment. Finally, we expand on how bias amplification should be reasoned about when distinct clinically relevant effects on the outcome among those with an indication exist (effect-heterogeneity).

CONCLUSION

We conclude that studies using indication-based sampling should have robust justification - and that it should by no means be considered unbiased to adopt such approaches. As such, we suggest that future observational studies stay wary of bias amplification when considering drug indications.

Familial Hypercholesterolemia: Pitfalls and Challenges in Diagnosis and Treatment

Familial hypercholesterolemia (FH), a condition, which is characterized by a life-long exposure to markedly elevated low-density lipoprotein (LDL) concentrations from birth, and it still remains underdiagnosed and undertreated, despite the fact that its heterogeneous form represents one of the commonest genetic disorders to date. Indeed, only 10% of all estimated affected individuals have been diagnosed worldwide and for the most of them diagnosis comes too late, when atherosclerotic cardiovascular disease (ASCVD) has already been developed. Undiagnosed and undertreated FH leads to accelerated ASCVD with a high rate of premature deaths. Recently, several novel treatment modalities have been introduced, especially for the management of severe hypercholesterolemia. Nonetheless, a substantial number of FH patients still do not achieve guideline-recommended LDL cholesterol target values. In the present review we will summarize and critically discuss pitfalls and challenges in successful diagnosis and treatment of FH.

Algorithms for Treating Dyslipidemia in Youth

PURPOSE OF REVIEW

The goal of this article is to review algorithms for treating dyslipidemia in youth, discuss pitfalls, propose enhanced algorithms to address pitfalls, and consider future directions.

RECENT FINDINGS

The presence of modifiable and non-modifiable cardiovascular disease (CVD) risk factors during childhood is associated with CVD-related events in adulthood. Recent data has shown that childhood initiation of statin therapy in youth < 18 years of age with familial hypercholesterolemia reduces the risk of adult CVD. However, pediatric dyslipidemia remains undertreated in part due to a lack of primary health care providers with adequate understanding of screening guidelines and pediatric lipidologists with experience in treatment and follow-up of this unique population. Management algorithms have been published by the National Heart, Lung, and Blood Institute and American Heart Association as tools to empower clinicians to manage dyslipidemia. We propose enhanced algorithms, which incorporate recently approved pharmacotherapy to address the management gaps. Future algorithms based upon clinical risk scores may enhance treatment and improve outcomes. Algorithms for dyslipidemia management which target youth < 18 years of age are tools which empower clinicians to manage dyslipidemia in this unique population. Enhanced algorithms may help address pitfalls. We acknowledge the need for further risk assessment tools in pediatrics for tailored dyslipidemia management.

Chronic-binge ethanol feeding aggravates systemic dyslipidemia in Ldlr-/- mice, thereby accelerating hepatic fibrosis

Objective

Chronic ethanol consumption is known to cause alcohol-associated liver disease, which poses a global health concern as almost a quarter of heavy drinkers develop severe liver damage. Alcohol-induced liver disease ranges from a mild, reversible steatotic liver to alcoholic steatohepatitis and irreversible liver fibrosis and cirrhosis, ultimately requiring liver transplantation. While ethanol consumption is associated with dysregulated lipid metabolism and altered cholesterol homeostasis, the impact of dyslipidemia and pre-existing hypercholesterolemia on the development of alcohol-associated liver disease remains to be elucidated.

Design

To address the influence of systemic dyslipidemia on ethanol-induced liver disease, chronic-binge ethanol feeding was applied to female C57BL/6J (wild type) mice and mice deficient for the low-density lipoprotein receptor (Ldlr-/-), which display a human-like lipoprotein profile with elevated cholesterol and triglyceride levels in circulation. Respective control groups were pair-fed an isocaloric diet.

Results

Chronic-binge ethanol feeding did not alter systemic lipid levels in wild type mice. While increased systemic cholesterol levels in Ldlr-/- mice were not affected by ethanol feeding, chronic-binge ethanol diet aggravated elevated plasma triglyceride levels in Ldlr-/- mice. Despite higher circulatory triglyceride levels in Ldlr-/- mice, hepatic lipid levels and the development of hepatic steatosis were not different from wild type mice after ethanol diet, while hepatic expression of genes related to lipid metabolism (Lpl) and transport (Cd36) showed minor changes. Immunohistochemical assessment indicated a lower induction of infiltrating neutrophils in the livers of ethanol-fed Ldlr-/- mice compared to wild type mice. In line, hepatic mRNA levels of the pro-inflammatory genes Ly6g, Cd11b, Ccr2, Cxcl1 and F4/80 were reduced, indicating less inflammation in the livers of Ldlr-/- mice which was associated with reduced Tlr9 induction. While systemic ALT and hepatic MDA levels were not different, Ldlr-deficient mice showed accelerated liver fibrosis development after chronic-binge ethanol diet than wild type mice, as indicated by increased levels of Sirius Red staining and higher expression of pro-fibrotic genes Tgfb, Col1a1 and Col3a1. Ldlr-/- and wild type mice had similar plasma ethanol levels and did not show differences in the hepatic mRNA levels of Adh1 and Cyp2e1, important for ethanol metabolism.

Conclusion

Our results highlight that chronic-binge ethanol feeding enhances systemic dyslipidemia in Ldlr-/- mice which might accelerate the development of hepatic fibrosis, independent of hepatic lipid levels.

Effect of causative genetic variants on atherosclerotic cardiovascular disease in heterozygous familial hypercholesterolemia patients

Background

Heterozygous familial hypercholesterolemia (HFH) is an autosomal dominant genetic disorder leading to a lifetime exposure to high low-density lipoprotein cholesterol (LDL-c) level and an increased risk of premature atherosclerotic cardiovascular disease (ASCVD). We evaluate the effect of a causative genetic variant to predict ASCVD in HFH patients undergoing treatment.

Materials and methods

A retrospective cohort was conducted on 289 patients with possible, probable, and definite diagnosis of HFH according to Dutch Lipid Clinic Network Score and in whom DNA analyses were performed and mean LDL-c level was above 155 mg/dl. The study population was divided into groups based on the presence or not of a causative variant (pathogenic or likely pathogenic). We observed each of the study's participants for the occurrence of ASCVD.

Results

A causative variant was detected in 42.2% of study participants, and ASCVD has occurred in 21.5% of HFH patients. The incidence of ASCVD (27% vs. 17.4%, p = 0.048) and the mean of LDL-c under an optimal medical treatment (226 ± 59 mg/dl vs. 203 ± 37 mg/dl, p = 0.001) were higher in HFH-causative variant carriers than others. After adjusting on confounders, ASCVD was positively associated with LDL-c level [OR = 2.347; 95% (1.305-4.221), p = 0.004] and tends toward a negative association with HDL-c level [OR = 0.140; 95% (0.017-1.166), p = 0.059]. There is no more association between the detection of a causative variant and the occurrence of ASCVD [OR = 1.708; 95% (0.899-3.242), p = 0.102]. Kaplan Meier and log rank test showed no significant differences in event-free survival analysis between study groups (p = 0.523).

Conclusion

In this study population under medical care, it seems that the presence of a causative variant did not represent an independent predictor of adverse cardiovascular outcomes in HFH patients, and LDL-c level played an undisputable causal role.

Protein structural insights into a rare PCSK9 gain-of-function variant (R496W) causing familial hypercholesterolemia in a Saudi family: whole exome sequencing and computational analysis

Familial hypercholesterolemia (FH) is a globally underdiagnosed genetic condition associated with premature cardiovascular death. The genetic etiology data on Arab FH patients is scarce. Therefore, this study aimed to identify the genetic basis of FH in a Saudi family using whole exome sequencing (WES) and multidimensional bioinformatic analysis. Our WES findings revealed a rare heterozygous gain-of-function variant (R496W) in the exon 9 of the PCSK9 gene as a causal factor for FH in this family. This variant was absent in healthy relatives of the proband and 200 healthy normolipidemic controls from Saudi Arabia. Furthermore, this variant has not been previously reported in various regional and global population genomic variant databases. Interestingly, this variant is classified as "likely pathogenic" (PP5) based on the variant interpretation guidelines of the American College of Medical Genetics (ACMG). Computational functional characterization suggested that this variant could destabilize the native PCSK9 protein and alter its secondary and tertiary structural features. In addition, this variant was predicted to negatively influence its ligand-binding ability with LDLR and Alirocumab antibody molecules. This rare PCSK9 (R496W) variant is likely to expand our understanding of the genetic basis of FH in Saudi Arabia. This study also provides computational structural insights into the genotype-protein phenotype relationship of PCSK9 pathogenic variants and contributes to the development of personalized medicine for FH patients in the future.

Prevalence of familial hypercholesterolemia in a country-wide laboratory network in Pakistan: 10-year data from 988, 306 patients

INTRODUCTION

Familial hypercholesterolemia (FH) is a modifiable risk factor for premature coronary heart disease but is poorly diagnosed and treated. We leveraged a large laboratory network in Pakistan to study the prevalence, gender and geographic distribution of FH.

METHODOLOGY

Data were curated from the Aga Khan University Hospital clinical laboratories, which comprises of 289 laboratories and collection points spread over 94 districts. Clinically ordered lipid profiles from 1st January 2009 to 30th June 2018 were included and data on 1,542,281 LDL-C values was extracted. We used the Make Early Diagnosis to Prevent Early Death (MEDPED) criteria to classify patients as FH and reported data on patients with low-density liporotein -cholesterol (LDL-C) ≥ 190 mg/dL. FH cases were also examined by their spatial distribution.

RESULTS

After applying exclusions, the final sample included 988,306 unique individuals, of which 24,273 individuals (1:40) had LDL-C values of ≥190 mg/dL. Based on the MEDPED criteria, 2416 individuals (1:409) had FH. FH prevalence was highest in individuals 10-19 years (1:40) and decreased as the patient age increased. Among individuals ≥40 years, the prevalence of FH was higher for females compared with males (1:755 vs 1:1037, p < 0.001). Median LDL-C for the overall population was 112 mg/dL (IQR = 88-136 mg/dL). The highest prevalence after removing outliers was observed in Rajan Pur district (1.23% [0.70-2.10%]) in Punjab province, followed by Mardan (1.18% [0.80-1.70%]) in Khyber Pakhtunkhwa province, and Okara (0.99% [0.50-1.80%]) in Punjab province.

CONCLUSION

There is high prevalence of actionable LDL-C values in lipid samples across a large network of laboratories in Pakistan. Variable FH prevalence across geographic locations in Pakistan may need to be explored at the population level for intervention and management of contributory factors. Efforts at early diagnosis and treatment of FH are urgently needed.

Painful and recurring injection site reaction to alirocumab and evolocumab in a young woman with familial hypercholesterolemia and effective therapeutic alternative based on inclisiran: a case report

A 28-year-old woman with autosomal dominant familial hypercholesterolemia (FH) with a probable coexistent polygenic contribution causing very high low-density lipoprotein-cholesterol (LDL-C) levels, started therapy with the proprotein convertase subtilisin/kexin type 9-inhibitor (PCSK9i) alirocumab, in addition to high-intensity statin plus ezetimibe. Forty-eight hours after the second injection of alirocumab, the patient developed a painful palpable injection site reaction (ISR) that recurred after the third administration of the drug. Treatment was then switched to evolocumab, another PCSK9i, but the patient had an ISR with similar features. The most conceivable cause of the ISR was a cell-mediated hypersensitivity reaction to polysorbate, an excipient contained in both drugs. Although ISR after PCSK9i administration is usually transient and does not compromise the continuation of treatment, in this case the recurrence of such side effect in an exacerbated way led to treatment withdrawal, with a subsequent re-exposure to increased cardiovascular (CV) risk. As soon as it became available in clinical practice, the patient started treatment with inclisiran, a small interfering RNA targeting hepatic PCSK9 synthesis. No adverse events were reported after inclisiran administration and LDL-C levels decreased significantly, confirming the evidence that this innovative approach to hypercholesterolemia is a safe and effective resource in patients at high CV risk who cannot achieve LDL-C goal with conventional lipid-lowering therapies and antibody-based PCSK9i.

The Potential Therapeutic Application of Simvastatin for Brain Complications and Mechanisms of Action

Statins are common drugs that are clinically used to reduce elevated plasma cholesterol levels. Based on their solubility, statins are considered to be either hydrophilic or lipophilic. Amongst them, simvastatin has the highest lipophilicity to facilitate its ability to cross the blood-brain barrier. Recent studies have suggested that simvastatin could be a promising therapeutic option for different brain complications and diseases ranging from brain tumors (i.e., medulloblastoma and glioblastoma) to neurological disorders (i.e., Alzheimer's disease, Parkinson's disease, and Huntington's disease). Specific mechanisms of disease amelioration, however, are still unclear. Independent studies suggest that simvastatin may reduce the risk of developing certain neurodegenerative disorders. Meanwhile, other studies point towards inducing cell death in brain tumor cell lines. In this review, we outline the potential therapeutic effects of simvastatin on brain complications and review the clinically relevant molecular mechanisms in different cases.

Reducing Premature Coronary Artery Disease in Malaysia by Early Identification of Familial Hypercholesterolemia Using the Familial Hypercholesterolemia Case Ascertainment Tool (FAMCAT): Protocol for a Mixed Methods Evaluation Study

BACKGROUND

Familial hypercholesterolemia (FH) is predominantly caused by mutations in the 4 FH candidate genes (FHCGs), namely, low-density lipoprotein receptor (LDLR), apolipoprotein B-100 (APOB-100), proprotein convertase subtilisin/kexin type 9 (PCSK9), and the LDL receptor adaptor protein 1 (LDLRAP1). It is characterized by elevated low-density lipoprotein cholesterol (LDL-c) levels leading to premature coronary artery disease. FH can be clinically diagnosed using established clinical criteria, namely, Simon Broome (SB) and Dutch Lipid Clinic Criteria (DLCC), and can be identified using the Familial Hypercholesterolemia Case Ascertainment Tool (FAMCAT), a primary care screening tool.

OBJECTIVE

This study aims to (1) compare the detection rate of genetically confirmed FH and diagnostic accuracy between the FAMCAT, SB, and DLCC in the Malaysian primary care setting; (2) identify the genetic mutation profiles, including novel variants, in individuals with suspected FH in primary care; (3) explore the experience, concern, and expectation of individuals with suspected FH who have undergone genetic testing in primary care; and (4) evaluate the clinical utility of a web-based FH Identification Tool that includes the FAMCAT, SB, and DLCC in the Malaysian primary care setting.

METHODS

This is a mixed methods evaluation study conducted in 11 Ministry of Health primary care clinics located at the central administrative region of Malaysia. In Work stream 1, the diagnostic accuracy study design is used to compare the detection rate and diagnostic accuracy of the FAMCAT, SB, and DLCC against molecular diagnosis as the gold standard. In Work stream 2, the targeted next-generation sequencing of the 4 FHCGs is used to identify the genetic mutation profiles among individuals with suspected FH. In Work stream 3a, a qualitative semistructured interview methodology is used to explore the experience, concern, and expectation of individuals with suspected FH who have undergone genetic testing. Lastly, in Work stream 3b, a qualitative real-time observation of primary care physicians using the "think-aloud" methodology is applied to evaluate the clinical utility of a web-based FH Identification Tool.

RESULTS

The recruitment for Work stream 1, and blood sampling and genetic analysis for Work stream 2 were completed in February 2023. Data collection for Work stream 3 was completed in March 2023. Data analysis for Work streams 1, 2, 3a, and 3b is projected to be completed by June 2023, with the results of this study anticipated to be published by December 2023.

CONCLUSIONS

This study will provide evidence on which clinical diagnostic criterion is the best to detect FH in the Malaysian primary care setting. The full spectrum of genetic mutations in the FHCGs including novel pathogenic variants will be identified. Patients' perspectives while undergoing genetic testing and the primary care physicians experience in utilizing the web-based tool will be established. These findings will have tremendous impact on the management of patients with FH in primary care and subsequently reduce their risk of premature coronary artery disease.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/47911.

A Machine Learning Model to Aid Detection of Familial Hypercholesterolemia

Background

People with monogenic familial hypercholesterolemia (FH) are at an increased risk of premature coronary heart disease and death. With a prevalence of 1:250, FH is relatively common; but currently there is no population screening strategy in place and most carriers are identified late in life, delaying timely and cost-effective interventions.

Objectives

The purpose of this study was to derive an algorithm to identify people with suspected monogenic FH for subsequent confirmatory genomic testing and cascade screening.

Methods

A least absolute shrinkage and selection operator logistic regression model was used to identify predictors that accurately identified people with FH in 139,779 unrelated participants of the UK Biobank. Candidate predictors included information on medical and family history, anthropometric measures, blood biomarkers, and a low-density lipoprotein cholesterol (LDL-C) polygenic score (PGS). Model derivation and evaluation were performed in independent training and testing data.

Results

A total of 488 FH variant carriers were identified using whole-exome sequencing of the low-density lipoprotein receptor, apolipoprotein B, apolipoprotein E, proprotein convertase subtilisin/kexin type 9 genes. A 14-variable algorithm for FH was derived, with an area under the curve of 0.77 (95% CI: 0.71-0.83), where the top 5 most important variables included triglyceride, LDL-C, apolipoprotein A1 concentrations, self-reported statin use, and LDL-C PGS. Excluding the PGS as a candidate feature resulted in a 9-variable model with a comparable area under the curve: 0.76 (95% CI: 0.71-0.82). Both multivariable models (w/wo the PGS) outperformed screening-prioritization based on LDL-C adjusted for statin use.

Conclusions

Detecting individuals with FH can be improved by considering additional predictors. This would reduce the sequencing burden in a 2-stage population screening strategy for FH.

Genetic Testing for Familial Hypercholesterolemia in Clinical Practice

PURPOSE OF REVIEW

Genetic testing has proven utility in identifying and diagnosing individuals with FH. Here we outline the current landscape of genetic testing for FH, recommendations for testing practices and the efforts underway to improve access, availability, and uptake.

RECENT FINDINGS

Alternatives to the traditional genetic testing and counseling paradigm for FH are being explored including expanding screening programs, testing in primary care and/or cardiology clinics, leveraging electronic communication tools like chatbots, and implementing direct contact approaches to facilitate genetic testing of both probands and at-risk relatives. There is no consensus on if, when, and how genetic testing or accompanying genetic counseling should be provided for FH, though traditional genetic counseling and/or testing in specialty lipid clinics is often recommended in expert statements and professional guidelines. More evidence is needed to determine whether alternative approaches to the implementation of genetic testing for FH may be more effective.

Hyperlipidemia and Cardiovascular Risk in Children and Adolescents

Atherosclerotic cardiovascular disease (ASCVD) represents the major cause of morbidity and mortality worldwide. The onset of the atherosclerosis process occurs during childhood and adolescence, subsequently leading to the onset of cardiovascular disease as young adults. Several cardiovascular risk factors can be identified in children and adolescents; however, hyperlipidemia, in conjunction with the global obesity epidemic, has emerged as the most prevalent, playing a key role in the development of ASCVD. Therefore, screening for hyperlipidemia is strongly recommended to detect high-risk children presenting with these disorders, as these patients deserve more intensive investigation and intervention. Treatment should be initiated as early as possible in order to reduce the risk of future ASCVD. In this review, we will discuss lipid metabolism and hyperlipidemia, focusing on correlations with cardiovascular risk and screening and therapeutic management to reduce or almost completely avoid the development of ASCVD.