Diagnostic Yield and Clinical Utility of Sequencing Familial Hypercholesterolemia Genes in Patients With Severe Hypercholesterolemia

Familial hypercholesterolemia

Familial hypercholesterolemia is a common genetic disorder of autosomal inheritance associated with elevated LDL-cholesterol. It is estimated to affect 1:250 individuals in general population roughly estimated to be 5 million in India. The prevalence of FH is higher in young CAD patients (<55 years in men; <60 years in women). FH is underdiagnosed and undertreated. Screening during childhood and Cascade screening of family members of known FH patients is of utmost importance in order to prevent the burden of CAD. Early identification of FH patients and early initiation of the lifelong lipid lowering therapy is the most effective strategy for managing FH. FH management includes pharmaceutical agents (statins and non statin drugs) and lifestyle modification. Inspite of maximum dose of statin with or without Ezetimibe, if target levels of LDL-C are not achieved, Bempedoic acid, proprotein convertase subtilisin/kexin type 9 (PCSK9) Inhibitors/Inclisiran can be added.

Genetic Counseling and Genetic Testing for Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is one of the most common autosomal codominant Mendelian diseases. The major complications of FH include tendon and cutaneous xanthomas and coronary artery disease (CAD) associated with a substantial elevation of serum low-density lipoprotein levels (LDL). Genetic counseling and genetic testing for FH is useful for its diagnosis, risk stratification, and motivation for further LDL-lowering treatments. In this study, we summarize the epidemiology of FH based on numerous genetic studies, including its pathogenic variants, genotype-phenotype correlation, prognostic factors, screening, and usefulness of genetic counseling and genetic testing. Due to the variety of treatments available for this common Mendelian disease, genetic counseling and genetic testing for FH should be implemented in daily clinical practice.

2024 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2024 AHA Statistical Update is the product of a full year's worth of effort in 2023 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. The AHA strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional global data, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

A method to estimate the contribution of rare coding variants to complex trait heritability

It has been postulated that rare coding variants (RVs; MAF < 0.01) contribute to the "missing" heritability of complex traits. We developed a framework, the Rare variant heritability (RARity) estimator, to assess RV heritability (h2RV) without assuming a particular genetic architecture. We applied RARity to 31 complex traits in the UK Biobank (n = 167,348) and showed that gene-level RV aggregation suffers from 79% (95% CI: 68-93%) loss of h2RV. Using unaggregated variants, 27 traits had h2RV > 5%, with height having the highest h2RV at 21.9% (95% CI: 19.0-24.8%). The total heritability, including common and rare variants, recovered pedigree-based estimates for 11 traits. RARity can estimate gene-level h2RV, enabling the assessment of gene-level characteristics and revealing 11, previously unreported, gene-phenotype relationships. Finally, we demonstrated that in silico pathogenicity prediction (variant-level) and gene-level annotations do not generally enrich for RVs that over-contribute to complex trait variance, and thus, innovative methods are needed to predict RV functionality.

Long-Term Mortality in Patients With Severe Hypercholesterolemia Phenotype From a Racial and Ethnically Diverse US Cohort

BACKGROUND

Tools for mortality prediction in patients with the severe hypercholesterolemia phenotype (low-density lipoprotein cholesterol ≥190 mg/dL) are limited and restricted to specific racial and ethnic cohorts. We sought to evaluate the predictors of long-term mortality in a large racially and ethnically diverse US patient cohort with low-density lipoprotein cholesterol ≥190 mg/dL.

METHODS

We conducted a retrospective analysis of all patients with a low-density lipoprotein cholesterol ≥190 mg/dL seeking care at Montefiore from 2010 through 2020. Patients <18 years of age or with previous malignancy were excluded. The primary end point was all-cause mortality. Analyses were stratified by age, sex, and race and ethnicity. Patients were stratified by primary and secondary prevention. Cox regression analyses were used to adjust for demographic, clinical, and treatment variables.

RESULTS

A total of 18 740 patients were included (37% non-Hispanic Black, 30% Hispanic, 12% non-Hispanic White, and 2% non-Hispanic Asian patients). The mean age was 53.9 years, and median follow-up was 5.2 years. Both high-density lipoprotein cholesterol and body mass index extremes were associated with higher mortality in univariate analyses. In adjusted models, higher low-density lipoprotein cholesterol and triglyceride levels were associated with an increased 9-year mortality risk (adjusted hazard ratio [HR], 1.08 [95% CI, 1.05-1.11] and 1.04 [95% CI, 1.02-1.06] per 20-mg/dL increase, respectively). Clinical factors associated with higher mortality included male sex (adjusted HR, 1.31 [95% CI, 1.08-1.58]), older age (adjusted HR, 1.19 per 5-year increase [95% CI, 1.15-1.23]), hypertension (adjusted HR, 2.01 [95% CI, 1.57-2.57]), chronic kidney disease (adjusted HR, 1.68 [95% CI, 1.36-2.09]), diabetes (adjusted HR, 1.79 [95% CI, 1.50-2.15]), heart failure (adjusted HR, 1.51 [95% CI, 1.16-1.95]), myocardial infarction (adjusted HR, 1.41 [95% CI, 1.05-1.90]), and body mass index <20 kg/m2 (adjusted HR, 3.36 [95% CI, 2.29-4.93]). A significant survival benefit was conferred by lipid-lowering therapy (adjusted HR, 0.57 [95% CI, 0.42-0.77]). In the primary prevention group, high-density lipoprotein cholesterol <40 mg/dL was independently associated with higher mortality (adjusted HR, 1.49 [95% CI, 1.06-2.09]). Temporal trend analyses showed a reduction in statin use over time (P<0.001). In the most recent time period (2019-2020), 56% of patients on primary prevention and 85% of those on secondary prevention were on statin therapy.

CONCLUSIONS

In a large, diverse cohort of US patients with the severe hypercholesterolemia phenotype, we identified several patient characteristics associated with increased 9-year all-cause mortality and observed a decrease in statin use over time, in particular for primary prevention. Our results support efforts geared toward early recognition and consistent treatment for patients with severe hypercholesterolemia.

Familial Hypercholesterolemia in the Elderly: An Analysis of Clinical Profile and Atherosclerotic Cardiovascular Disease Burden from the Hellas-FH Registry

BACKGROUND

Familial hypercholesterolemia (FH) carries a high risk of atherosclerotic cardiovascular disease (ASCVD). As the population ages, the age-related influence on clinical characteristics and outcomes becomes increasingly pertinent. This cross-sectional analysis from the HELLAS-FH registry aims to explore potential differences in clinical characteristics, treatment, ASCVD, and goal achievement between those younger and older than 65 years with FH.

RESULTS

A total of 2273 adults with heterozygous FH (51.4% males) were studied. Elderly FH patients (n = 349) had a higher prevalence of ASCVD risk factors, such as hypertension (52.1% vs. 20.9%, p < 0.05) and type 2 diabetes (16.9% vs. 6.0%, p < 0.05), compared to younger patients (n = 1924). They also had a higher prevalence of established ASCVD (38.4% vs. 23.1%, p < 0.001), particularly CAD (33.0% vs. 20.2%, p < 0.001), even after adjusting for major ASCVD risk factors. Elderly patients were more frequently and intensively receiving lipid-lowering treatment than younger ones. Although post-treatment LDL-C levels were lower in elderly than younger patients (125 vs. 146 mg/dL, p < 0.05), both groups had similar attainment of the LDL-C target (3.7% vs. 3.0%).

CONCLUSIONS

Elderly FH patients have a higher prevalence of ASCVD, particularly CAD. Despite more aggressive treatment, the achievement of LDL-C targets remains very poor. These results emphasize the importance of early FH diagnosis and treatment in reducing ASCVD.

Competing Genetic Traits and Their Influence on LDL Cholesterol Concentration in Familial Hypercholesterolemia

Familial hypercholesterolemia is a monogenic disorder that leads to premature atherosclerosis as a result of lifelong exposure to elevated low-density lipoprotein cholesterol (LDL-C). Both genetic traits and lifestyle factors can influence LDL-C levels. Adults with LDL-C of 170 mg/dL and higher may benefit from genetic evaluation to accurately assess their risk of atherosclerosis.

Dyslipidaemia as a target for atherosclerotic cardiovascular disease prevention in children with type 1 diabetes: lessons learned from familial hypercholesterolaemia

In the last few decades, atherosclerotic cardiovascular disease (ASCVD) risk has decreased dramatically among individuals affected by familial hypercholesterolaemia (FH) as a result of the early initiation of statin treatment in childhood. Contemporaneously important improvements in care for people with diabetes have also been made, such as the prevention of mortality from acute diabetic complications. However, individuals with type 1 diabetes still have a two to eight times higher risk of death than the general population. In the last 20 years, a few landmark studies on excess mortality in people with type 1 diabetes, in particular young adults, have been published. Although these studies were carried out in different populations, all reached the same conclusion: individuals with type 1 diabetes have a pronounced increased risk of ASCVD. In this review, we address the role of lipid abnormalities in the development of ASCVD in type 1 diabetes and FH. Although type 1 diabetes and FH are different diseases, lessons could be learned from the early initiation of statins in children with FH, which may provide a rationale for more stringent control of dyslipidaemia in children with type 1 diabetes.

Navigating the prime editing strategy to treat cardiovascular genetic disorders in transforming heart health

INTRODUCTION

After understanding the genetic basis of cardiovascular disorders, the discovery of prime editing (PE), has opened new horizons for finding their cures. PE strategy is the most versatile editing tool to change cardiac genetic background for therapeutic interventions. The optimization of elements, prediction of efficiency, and discovery of the involved genes regulating the process have not been completed. The large size of the cargo and multi-elementary structure makes the in vivo heart delivery challenging.

AREAS COVERED

Updated from recent published studies, the fundamentals of the PEs, their application in cardiology, potentials, shortcomings, and the future perspectives for the treatment of cardiac-related genetic disorders will be discussed.

EXPERT OPINION

The ideal PE for the heart should be tissue-specific, regulatable, less immunogenic, high transducing, and safe. However, low efficiency, sup-optimal PE architecture, the large size of required elements, the unclear role of transcriptomics on the process, unpredictable off-target effects, and its context-dependency are subjects that need to be considered. It is also of great importance to see how beneficial or detrimental cell cycle or epigenomic modifier is to bring changes into cardiac cells. The PE delivery is challenging due to the size, multi-component properties of the editors and liver sink.

Association of Clinical Characteristics With Familial Hypercholesterolaemia Variants in a Lipid Clinic Setting: A Case-Control Study

Objective

Familial hypercholesterolaemia (FH) variant positive subjects have over double the cardiovascular risk of low-density-lipoprotein-cholesterol (LDL-C) matched controls. It is desirable to optimise FH variant detection.

Methods

We identified 213 subjects with FH gene panel reports (LDLR, APOB, PCSK9, and APOE) based on total cholesterol >310 mg/dL; excluding triglycerides >400 mg/dL, cascade screening, and patients without pre-treatment LDL-C recorded. Demographic, clinical and lipid parameters were recorded.

Results

A 31/213 (14.6%) patients had pathogenic or likely pathogenic FH variants. 10/213 (4.7%) had variants of uncertain significance. Compared with patients without FH variants, patients with FH variants were younger (median age, 39 years vs. 48 years), had more tendon xanthomata (25.0% vs. 11.4%), greater proportion of first degree relatives with total cholesterol >95th percentile (40.6% vs. 16.5%), higher LDL-C (median, 271 mg/dL vs. 236 mg/dL), and lower triglycerides (median, 115 mg/dL vs. 159 mg/dL). The Besseling et al. model (c-statistic 0.798) improved FH variant discrimination over Friedewald LDL-C (c-statistic 0.724), however, Dutch Lipid Clinic Network Score (DLCNS) did not (c-statistic 0.665). Sampson LDL-C (c-statistic 0.734) had similar discrimination to Friedewald.

Conclusion

Although tendon xanthomata and first degree relatives with high total cholesterol >95th percentile were associated with FH variants, DLCNS or Simon Broome criteria did not improve FH detection over LDL-C. Sampson LDL-C did not significantly improve discrimination over Friedewald. Although lower triglycerides and younger age of presentation are positively associated with presence of FH variants, this information is not commonly used in FH detection algorithms apart from Besseling et al.

Predictors of cardiovascular risk in familial hypercholesterolemia

PURPOSE OF REVIEW

Familial hypercholesterolemia is associated with an increased risk of cardiovascular disease. The current international guidelines of the main scientific societies consider that, all people with Familial Hypercholesterolemia have a high or very high cardiovascular risk. However, the occurrence of atherosclerotic cardiovascular disease is very heterogeneous in this population. Stratifying risk within people with familial hypercholesterolemia is essential to identify individuals who require intensive cholesterol-lowering therapies.

RECENT FINDINGS

In the last year, several studies have been published focusing on the contribution of diabetes to Familial Hypercholesterolemia, the role of stroke, as a manifestation of atherosclerotic disease, and the external validation of the SAFEHEART risk equation in the English population diagnosed with Familial Hypercholesterolemia.

SUMMARY

It is necessary the development of a tool that allows us to identify, in a simple, reproducible, and universal way, patients who may have a high risk of suffering a cardiovascular event and who are susceptible to more intensive treatments to reduce cholesterol levels.

Stratification in Heterozygous Familial Hypercholesterolemia: Imaging, Biomarkers, and Genetic Testing

PURPOSE OF REVIEW

Heterozygous familial hypercholesterolemia (HeFH) is the most common monogenic autosomal dominant disorder. However, the condition is often underdiagnosed and undertreated. The objective of this review is to provide an update on the risk stratification in patients with HeFH, incorporating new cardiovascular imaging techniques, various biomarkers, and genetic studies.

RECENT FINDINGS

The diagnosis of HeFH places patients in a high cardiovascular risk category due to the increased incidence of premature atherosclerotic cardiovascular disease. However, the level of risk varies significantly among different individuals with HeFH. Achieving an optimal stratification of cardiovascular risk is crucial for establishing appropriate and accurate treatment and management strategies. Different new tools such as risk scores have emerged in recent years, aiding physicians in assessing the risk stratification for HeFH using imaging, biomarkers, and genetics. This review emphasizes that not all patients with HeFH face the same cardiovascular risk. By utilizing different assessment tools, we can identify those who require more intensive monitoring, follow-up, and treatment.

Novel Finnish-enriched variants causing severe hypercholesterolemia and their clinical impact on coronary artery disease

BACKGROUND AND AIMS

Severe hypercholesterolemia (LDL-cholesterol ≥ 5 mmol/l) is a major risk factor for coronary artery disease (CAD). The etiology incudes both genetic and nongenetic factors, but persons carrying mutations in known hypercholesterolemia-associated genes are at significantly higher CAD risk than non-carriers. Yet, a significant proportion of mutation carriers remains undetected while the assessment of genetic candidate variants in clinical practice is challenging.

METHODS

To address these challenges, we set out to test the utility of a practical approach to leverage data from a large reference cohort, the FinnGen Study encompassing 356,082 persons with extensive longitudinal health record information, to aid the clinical evaluation of single genetic candidate genes variants detected by exome sequence analysis in a target population of 351 persons with severe hypercholesterolemia.

RESULTS

We identified 23 rare missense mutations in known hypercholesterolemia genes, 3 of which were previously described mutations (LDLR Pro309Lysfs, LDLR Arg595Gln and APOB Arg3527Gln). Subsequent in silico and clinical assessment of the remaining 20 variants pinpointed two likely hypercholesterolemia-associated variants in LDLR (Arg574Leu and Glu626Lys) and one in LDLRAP1 (Arg151Trp). Heterozygous carriers of the novel LDLR and LDLRAP1 variants received statin treatment more often than non-carriers (OR 2.1, p = 1.8e-6 and OR 1.4, p = 0.001) and untreated carriers had higher risk for ischemic heart disease (OR 2.0, p = 0.03 and OR 1.8, p = 0.008).

CONCLUSIONS

Our data elucidate the wide spectrum of genetic variants impacting hypercholesterolemia and demonstrate the utility of a large reference population to assess the heterogeneous impact of candidate gene variants on cardiovascular disease risk.

Should Familial Hypercholesterolaemia Be Included in the UK Newborn Whole Genome Sequencing Programme?

PURPOSE OF REVIEW

The UK National Health Service (NHS) has recently announced a Newborn Genomes Programme (NGP) to identify infants with treatable inherited disorders using whole genome sequencing (WGS). Here, we address, for familial hypercholesterolaemia (FH), the four principles that must be met for the inclusion of a disorder in the NGP.

RECENT FINDINGS

Principle A: There is strong evidence that the genetic variants causing FH can be reliably detected. Principle B: A high proportion of individuals who carry an FH-causing variant are likely to develop early heart disease if left undiagnosed and not offered appropriate treatment. Principle C: Early intervention has been shown to lead to substantially improved outcomes in children with FH. Principle D: The recommended interventions are equitably accessible for all. FH meets all the Wilson and Jungner criteria for inclusion in a screening programme, and it also meets all four principles and therefore should be included in the Newborn Genomes Programme.

Longitudinal Control of Lipid Levels in Patients With Premature Coronary Artery Disease

Background

Lipid-lowering therapy (LLT) is a central aspect of the treatment of patients with coronary artery disease (CAD), and the benefits of LLT accrue over time. However, there are limited real-world data on longitudinal lipid control in patients with premature CAD.

Objectives

The purpose of this study was to assess longitudinal attainment of guideline-recommended lipid goals and outcomes in a contemporary cohort of patients with premature CAD.

Methods

We enrolled males younger than 50 years and females younger than 55 years with coronary stenosis of >50% and examined achievement of lipid goals, LLT characteristics, and cardiovascular outcomes (major adverse cardiovascular event [MACE]).

Results

Of 476 patients who presented with acute coronary syndrome (ST-elevation myocardial infarction, non-ST-segment elevation myocardial infarction, unstable angina) (68%), stable angina (28%), or other symptoms, 73.2% achieved low-density lipoprotein cholesterol (LDL-C) <1.8 mmol/L on at least 1 occasion, but only 27.3% consistently stayed in the target range for 3 years after diagnosis. Although 73.9% of patients received high-intensity LLT at the time of diagnosis, only 43.5% had good adherence over the following 3 years. In multivariable analysis, 1 mmol/L increase in time-weighted average exposure to LDL-C, but not the lowest achieved LDL-C, was associated with a higher risk of MACE, hazard ratio 2.02 (95% CI: 1.48-2.76), when adjusted for sex, age, hypertension, diabetes, and smoking.

Conclusions

We found low rates of longitudinal lipid target achievement in patients with premature CAD. Cumulative LDL-C exposure, but not lowest achieved LDL-C, was associated with risk of MACE. This highlights the critical importance of longitudinal control of lipids levels and identifies opportunities to improve LLT and maximize the time-dependent benefits of lipid-lowering.

International Atherosclerosis Society guidance for implementing best practice in the care of familial hypercholesterolaemia

This contemporary, international, evidence-informed guidance aims to achieve the greatest good for the greatest number of people with familial hypercholesterolaemia (FH) across different countries. FH, a family of monogenic defects in the hepatic LDL clearance pathway, is a preventable cause of premature coronary artery disease and death. Worldwide, 35 million people have FH, but most remain undiagnosed or undertreated. Current FH care is guided by a useful and diverse group of evidence-based guidelines, with some primarily directed at cholesterol management and some that are country-specific. However, none of these guidelines provides a comprehensive overview of FH care that includes both the lifelong components of clinical practice and strategies for implementation. Therefore, a group of international experts systematically developed this guidance to compile clinical strategies from existing evidence-based guidelines for the detection (screening, diagnosis, genetic testing and counselling) and management (risk stratification, treatment of adults or children with heterozygous or homozygous FH, therapy during pregnancy and use of apheresis) of patients with FH, update evidence-informed clinical recommendations, and develop and integrate consensus-based implementation strategies at the patient, provider and health-care system levels, with the aim of maximizing the potential benefit for at-risk patients and their families worldwide.

Genetic Spectrum and Cascade Screening of Familial Hypercholesterolemia in Routine Clinical Setting in Hong Kong

Familial hypercholesterolemia (FH) is a prevalent but often underdiagnosed monogenic disorder affecting lipoprotein metabolism, and genetic testing for FH has not been widely conducted in Asia in the past. In this cross-sectional study of 31 probands (19 adults and 12 children) and an addition of 15 individuals (12 adults and 3 children), who underwent genetic testing and cascade screening for FH, respectively, during the period between February 2015 and July 2023, we identified a total of 25 distinct LDLR variants in 71.0% unrelated probands. Among the adult proband cohort, a higher proportion of genetically confirmed cases exhibited a positive family history of premature cardiovascular disease. Treatment intensity required to achieve an approximate 50% reduction in pretreatment low-density lipoprotein cholesterol (LDL-C) exhibited potentially better diagnostic performance compared to pretreatment LDL-C levels, Dutch Lipid Clinic Network Diagnostic Criteria (DLCNC) score, and modified DLCNC score. Adult individuals identified through cascade screening demonstrated less severe phenotypes, and fewer of them met previously proposed local criteria for FH genetic testing compared to the probands, indicating that cascade screening played a crucial role in the early detection of new cases that might otherwise have gone undiagnosed. These findings underscore the significance of genetic testing and cascade screening in the accurate identification and management of FH cases.

Polygenic risk for triglyceride levels in the presence of a high impact rare variant

BACKGROUND

Elevated triglyceride (TG) levels are a heritable and modifiable risk factor for cardiovascular disease and have well-established associations with common genetic variation captured in a polygenic risk score (PRS). In young adulthood, the 22q11.2 microdeletion conveys a 2-fold increased risk for mild-moderate hypertriglyceridemia. This study aimed to assess the role of the TG-PRS in individuals with this elevated baseline risk for mild-moderate hypertriglyceridemia.

METHODS

We studied a deeply phenotyped cohort of adults (n = 157, median age 34 years) with a 22q11.2 microdeletion and available genome sequencing, lipid level, and other clinical data. The association between a previously developed TG-PRS and TG levels was assessed using a multivariable regression model adjusting for effects of sex, BMI, and other covariates. We also constructed receiver operating characteristic (ROC) curves using logistic regression models to assess the ability of TG-PRS and significant clinical variables to predict mild-moderate hypertriglyceridemia status.

RESULTS

The TG-PRS was a significant predictor of TG-levels (p = 1.52E-04), along with male sex and BMI, in a multivariable model (pmodel = 7.26E-05). The effect of TG-PRS appeared to be slightly stronger in individuals with obesity (BMI ≥ 30) (beta = 0.4617) than without (beta = 0.1778), in a model unadjusted for other covariates (p-interaction = 0.045). Among ROC curves constructed, the inclusion of TG-PRS, sex, and BMI as predictor variables produced the greatest area under the curve (0.749) for classifying those with mild-moderate hypertriglyceridemia, achieving an optimal sensitivity and specificity of 0.746 and 0.707, respectively.

CONCLUSIONS

These results demonstrate that in addition to significant effects of sex and BMI, genome-wide common variation captured in a PRS also contributes to the variable expression of the 22q11.2 microdeletion with respect to elevated TG levels.

Impact of conducting a genetic study on the management of familial hypercholesterolemia

BACKGROUND

Clinically diagnosed familial hypercholesterolemia (FH) may require a genetic test (GT) to confirm diagnosis. GT availability/accessibility is resource-dependent and usually restricted to specialized clinics. While GT has a diagnostic value, it has not yet defined its impact on long-term management and prognosis of FH.

OBJECTIVE

The aim was to identify the clinical characteristics associated with the request for a GT in suspected heterozygous FH.

METHODS

Retrospective study including adult patients with clinically suspected to be FH. Positive GT (GT+) was defined as having a pathogenic/likely pathogenic variant. Patients were stratified based on whether they had a genetic study conducted, and among those with a genetic study, according to those who did or did not have a GT+.

RESULTS

From 4854 patients included, 3090 were performed a GT (GT+: 2113). Median follow-up: 6.2 years. A younger age, FH-related physical signs, premature coronary disease, higher low-density lipoprotein cholesterol (LDLc) and lower body mass index and triglycerides, associated higher odds of being conducted a genetic study. These patients had higher baseline LDLc (252 mg/dL vs. 211 mg/dL among clinically diagnosed patients) and experienced larger reductions over the follow-up (157.7 mg/dL vs. 113.5 mg/dL, respectively). A similar pattern was observed among patients with GT+ (vs. negative GT). LDLc target attainment was low but increased to 66-95% when a triple combination with statin/ezetimibe/proprotein convertase subtilisin kexin type 9-inhibitor was used. Cardiovascular events occurred in 3.2% and 3.1% of patients who conducted/not conducted a genetic study. Patients conducted a genetic analysis and those with GT+ tended to present the events earlier.

CONCLUSIONS

Genetic study, vs. having a clinical-only diagnosis, impacts the management of FH. Cardiovascular prognosis was similar in both groups, perhaps as a result of the more intensive management of patients with a genetic study.

Barriers to and Facilitators of Implementing Guidelines for Detecting Familial Hypercholesterolaemia in Australia

BACKGROUND

Familial hypercholesterolaemia (FH) is a genetic condition that is a preventable cause of premature cardiovascular morbidity and mortality. High-level evidence and clinical practice guidelines support preventative care for people with FH. However, it is estimated that less than 10% of people at risk of FH have been detected using any approach across Australian health settings. The aim of this study was to identify the implementation barriers to and facilitators of the detection of FH in Australia.

METHODS

Four, 2-hour virtual focus groups were facilitated by implementation scientists and a clinicians as part of the 2021 Australasian FH Summit. Template analysis was used to identify themes.

RESULTS

There were 28 workshop attendees across four groups (n=6-8 each), yielding 13 barriers and 10 facilitators across three themes: (1) patient related, (2) provider related, and (3) system related. A "lack of care pathways" and "upskilling clinicians in identifying and diagnosing FH" were the most interconnected barriers and facilitators for the detection of FH.

CONCLUSIONS

The relationships between barriers and facilitators across the patient, provider, and system themes indicates that a comprehensive implementation strategy is needed to address these different levels. Future research is underway to develop a model for implementing the Australian FH guidelines into practice.

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.

Polygenic Background Modifies Risk of Coronary Artery Disease Among Individuals With Heterozygous Familial Hypercholesterolemia

Background

Heterozygous familial hypercholesterolemia (HeFH) is a monogenic disorder characterized by increased circulating low-density lipoprotein cholesterol and accelerated atherosclerosis. Even among this high-risk group, prior studies note considerable variability in risk of coronary artery disease (CAD).

Objectives

The purpose of this study was to evaluate the cumulative impact of many common DNA variants-as quantified by a polygenic score-on incident CAD among individuals carrying a HeFH variant.

Methods

We analyzed data from a prospective cohort study of 1,315 individuals who carried a HeFH variant and 1,315 matched family noncarriers derived from a nationwide screening program in the Netherlands, with subsequent replication in 151,009 participants of the UK Biobank.

Results

Despite identification and lipid management within the Dutch screening program, 84 (6.4%) of HeFH variant carriers developed CAD as compared to 45 (3.4%) of matched family members (median follow-up 10.2 years, HR 1.88, 95% CI: 1.31-2.70). Among HeFH variant carriers, a polygenic score was associated with CAD with an effect size similar to low-density lipoprotein cholesterol - HR of 1.35 (95% CI: 1.07-1.70) and 1.41 (95% CI: 1.17-1.70) per standard deviation increase, respectively. When compared to noncarriers, CAD risk increased from 1.24-fold (95% CI: 0.64-2.34) to 3.37-fold (95% CI: 2.11-5.36) across quintiles of the polygenic score. A similar risk gradient, 1.36-fold (95% CI: 0.65-2.85) to 2.88-fold (95% CI: 1.59-5.20), was observed in 429 carriers in the UK Biobank.

Conclusions

In 2 cohort studies involving 1,744 individuals with genetically confirmed HeFH - the largest study to date - risk of CAD varied according to polygenic background, in some cases approaching the risk observed in noncarriers.

Childhood Screening for Familial Hypercholesterolemia: JACC Review Topic of the Week

Screening for familial hypercholesterolemia (FH) in childhood remains controversial. Existing guidelines offer practitioners conflicting advice despite generally agreeing on the evidence and areas in which evidence is lacking, including a lack of long-term clinical trials demonstrating coronary event reduction as a result of screening and long-term data on statin side effects. A limitation of existing evidence-based frameworks is reliance on 1 evidence grading system to determine recommendations. However, rigorous evidence evaluation alternatives relevant to FH exist. FH is considered a tier 1 genetic condition, meaning that identification and treatment will improve health outcomes among those affected. Elevated low-density lipoprotein cholesterol, the primary consequence of FH, can be considered causal for atherosclerosis and coronary heart disease. Incorporating these concepts into existing evidence pathways allows the inclusion of surrogate clinical trial outcomes (low-density lipoprotein cholesterol reduction and atherosclerosis regression) and observational data on medication safety, strengthening the evidence for pediatric screening for FH.

Determination of Luteolin 7-Glucuronide in Perilla frutescens (L.) Britt. Leaf Extracts from Different Regions of China and Republic of Korea and Its Cholesterol-Lowering Effect

Lowering blood cholesterol levels is crucial for reducing the risk of cardiovascular disease in patients with familial hypercholesterolemia. To develop Perilla frutescens (L.) Britt. leaves as a functional food with a cholesterol-lowering effect, in this study, we collected P. frutescens (L.) Britt. leaves from different regions of China and Republic of Korea. On the basis of the extraction yield (all components; g/kg), we selected P. frutescens (L.) Britt. leaves from Hebei Province, China with an extract yield of 60.9 g/kg. After evaluating different concentrations of ethanol/water solvent for P. frutescens (L.) Britt. leaves, with luteolin 7-glucuronide as the indicator component, we selected a 30% ethanol/water solvent with a high luteolin 7-glucuronide content of 0.548 mg/g in Perilla. frutescens (L.) Britt. leaves. Subsequently, we evaluated the cholesterol-lowering effects of P. frutescens (L.) Britt. leaf extract and luteolin 7-glucuronide by detecting total cholesterol in HepG2 cells. The 30% ethanol extract lowered cholesterol levels significantly by downregulating 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase expression. This suggests that P. frutescens (L.) Britt leaves have significant health benefits and can be explored as a potentially promising food additive for the prevention of hypercholesterolemia-related diseases.

Low-Cost High-Throughput Genotyping for Diagnosing Familial Hypercholesterolemia

BACKGROUND

Familial hypercholesterolemia (FH) is a common but underdiagnosed genetic disorder characterized by high low-density lipoprotein cholesterol levels and premature cardiovascular disease. Current sequencing methods to diagnose FH are expensive and time-consuming. In this study, we evaluated the accuracy of a low-cost, high-throughput genotyping array for diagnosing FH.

METHODS

An Illumina Global Screening Array was customized to include probes for 636 variants, previously classified as FH-causing variants. First, its theoretical coverage was assessed in all FH variant carriers diagnosed through next-generation sequencing between 2016 and 2022 in the Netherlands (n=1772). Next, the performance of the array was validated in another sample of FH variant carriers previously identified in the Dutch FH cascade screening program (n=1268).

RESULTS

The theoretical coverage of the array for FH-causing variants was 91.3%. Validation of the array was assessed in a sample of 1268 carriers of whom 1015 carried a variant in LDLR, 250 in APOB, and 3 in PCSK9. The overall sensitivity was 94.7% and increased to 98.2% after excluding participants with variants not included in the array design. Copy number variation analysis yielded a 89.4% sensitivity. In 18 carriers, the array identified a total of 19 additional FH-causing variants. Subsequent DNA analysis confirmed 5 of the additionally identified variants, yielding a false-positive result in 16 subjects (1.3%).

CONCLUSIONS

The FH genotyping array is a promising tool for genetically diagnosing FH at low costs and has the potential to greatly increase accessibility to genetic testing for FH. Continuous customization of the array will further improve its performance.

Safety Net Program to Improve Statin Initiation Among Adults With High Low-Density Lipoprotein Cholesterol

INTRODUCTION

Despite their effectiveness in reducing low-density lipoprotein cholesterol and cardiovascular disease risk, high-intensity statins are underutilized among adults with low-density lipoprotein cholesterol ≥190 mg/dL. This study determined whether a safety net program (SureNet) facilitating medication and laboratory test orders improved statin initiation and laboratory test completions after (SureNet period: April 2019-September 2021) and before implementation (pre-SureNet period: January 2016-September 2018).

METHODS

Kaiser Permanente Southern California members aged 20-60 years with low-density lipoprotein cholesterol ≥190 mg/dL and no statin use in previous 2-6 months were included in this retrospective cohort study. Statin orders within 14 days and statin fills, laboratory test completions, and improved low-density lipoprotein cholesterol within 180 days of the high low-density lipoprotein cholesterol (pre-SureNet) or outreach (SureNet period) were compared. Analyses were conducted in 2022.

RESULTS

Overall, 3,534 and 3,555 adults were eligible for statin initiation during the pre-SureNet and SureNet periods, respectively. Overall, 759 (21.5%) and 976 (27.5%) had a statin approved by their physician during pre-SureNet and SureNet periods, respectively (p<0.001). After multivariable adjustment for demographics and clinical characteristics, adults during the SureNet period had a higher likelihood of receiving a statin order (prevalence ratio=1.36, 95% CI=1.25, 1.48), filling their statin (prevalence ratio=1.32, 95% CI=1.26, 1.38), completing their laboratories (prevalence ratio=1.41, 95% CI=1.26, 1.58), and improving low-density lipoprotein cholesterol (prevalence ratio=1.21, 95% CI=1.07, 1.37) than in pre-Surenet period.

CONCLUSIONS

The SureNet program was able to improve prescription orders, fills, laboratory test completions, and lower low-density lipoprotein cholesterol. Optimizing both physician adherence to treatment guidelines; and patient adherence to the program may improve low-density lipoprotein cholesterol lowering.

Subtyping Severe Hypercholesterolemia by Genetic Determinant to Stratify Risk of Coronary Artery Disease

BACKGROUND

Severe hypercholesterolemia, defined as LDL (low-density lipoprotein) cholesterol (LDL-C) measurement ≥190 mg/dL, is associated with increased risk for coronary artery disease (CAD). Causes of severe hypercholesterolemia include monogenic familial hypercholesterolemia, polygenic hypercholesterolemia, elevated lipoprotein(a) [Lp(a)] hypercholesteremia, polygenic hypercholesterolemia with elevated Lp(a) (two-hit), or nongenetic hypercholesterolemia. The added value of using a genetics approach to stratifying risk of incident CAD among those with severe hypercholesterolemia versus using LDL-C levels alone for risk stratification is not known.

METHODS

To determine whether risk stratification by genetic cause provided better 10-year incident CAD risk stratification than LDL-C level, a retrospective cohort study comparing incident CAD risk among severe hypercholesterolemia subtypes (genetic and nongenetic causes) was performed among 130 091 UK Biobank participants. Analyses were limited to unrelated, White British or Irish participants with available exome sequencing data. Participants with cardiovascular disease at baseline were excluded from analyses of incident CAD.

RESULTS

Of 130 091 individuals, 68 416 (52.6%) were women, and the mean (SD) age was 56.7 (8.0) years. Of the cohort, 9.0% met severe hypercholesterolemia criteria. Participants with LDL-C between 210 and 229 mg/dL and LDL-C ≥230 mg/dL showed modest increases in incident CAD risk relative to those with LDL-C between 190 and 209 mg/dL (210-229 mg/dL: hazard ratio [HR], 1.3 [95% CI, 1.1-1.7]; ≥230 mg/dL: HR, 1.3 [95% CI, 1.0-1.7]). In contrast, when risk was stratified by genetic subtype, monogenic familial hypercholesterolemia, elevated Lp(a), and two-hit hypercholesterolemia subtypes had increased rates of incident CAD relative to the nongenetic hypercholesterolemia subtype (monogenic familial hypercholesterolemia: HR, 2.3 [95% CI, 1.4-4.0]; elevated Lp(a): HR, 1.5 [95% CI, 1.2-2.0]; two-hit: HR, 1.9 [95% CI, 1.4-2.6]), while polygenic hypercholesterolemia did not.

CONCLUSIONS

Genetics-based subtyping for monogenic familial hypercholesterolemia and Lp(a) in those with severe hypercholesterolemia provided better stratification of 10-year incident CAD risk than LDL-C-based stratification.

Attainment of Low-Density Lipoprotein Cholesterol Targets and Prescribing Pattern of Lipid-Lowering Medications among Patients with Familial Hypercholesterolemia Attending Specialist Clinics

AIMS

Patients with familial hypercholesterolemia (FH) are known to have higher exposure to coronary risk than those without FH with similar low-density lipoprotein cholesterol (LDL-C) level. Lipid-lowering medications (LLMs) are the mainstay treatments to lower the risk of premature coronary artery disease in patients with hypercholesterolemia. However, the LLM prescription pattern and its effectiveness among Malaysian patients with FH are not yet reported. The aim of this study was to report the LLM prescribing pattern and its effectiveness in lowering LDL-C level among Malaysian patients with FH treated in specialist hospitals.

METHODS

Subjects were recruited from lipid and cardiac specialist hospitals. FH was clinically diagnosed using the Dutch Lipid Clinic Network Criteria. Patients' medical history was recorded using a standardized questionnaire. LLM prescription history and baseline LDL-C were acquired from the hospitals' database. Blood samples were acquired for the latest lipid profile assay.

RESULTS

A total of 206 patients with FH were recruited. Almost all of them were on LLMs (97.6%). Only 2.9% and 7.8% of the patients achieved the target LDL-C of ＜1.4 and ＜1.8 mmol/L, respectively. The majority of patients who achieved the target LDL-C were prescribed with statin-ezetimibe combination medications and high-intensity or moderate-intensity statins. All patients who were prescribed with ezetimibe monotherapy did not achieve the target LDL-C.

CONCLUSION

The majority of Malaysian patients with FH received LLMs, but only a small fraction achieved the therapeutic target LDL-C level. Further investigation has to be conducted to identify the cause of the suboptimal treatment target attainment, be it the factors of patients or the prescription practice.

Searching for new genes associated with the familial hypercholesterolemia phenotype using whole-genome sequencing and machine learning

One of the most common congenital metabolic disorders is familial hypercholesterolemia. Familial hypercholesterolemia is a condition caused by a type of genetic defect leading to a decreased rate of removal of low-density lipoproteins from the bloodstream and a pronounced increase in the blood level of total cholesterol. This disease leads to the early development of cardiovascular diseases of atherosclerotic etiology. Familial hypercholesterolemia is a monogenic disease that is predominantly autosomal dominant. Rare pathogenic variants in the LDLR gene are present in 75-85 % of cases with an identified molecular genetic cause of the disease, and variants in other genes (APOB, PCSK9, LDLRAP1, ABCG5, ABCG8, and others) occur at a frequency of < 5 % in this group of patients. A negative result of genetic screening for pathogenic variants in genes of the low-density lipoprotein receptor and its ligands does not rule out a diagnosis of familial hypercholesterolemia. In 20-40 % of cases, molecular genetic testing fails to detect changes in the above genes. The aim of this work was to search for new genes associated with the familial hypercholesterolemia phenotype by modern high-tech methods of sequencing and machine learning. On the basis of a group of patients with familial hypercholesterolemia (enrolled according to the Dutch Lipid Clinic Network Criteria and including cases confirmed by molecular genetic analysis), decision trees were constructed, which made it possible to identify cases in the study population that require additional molecular genetic analysis. Five probands were identified as having the severest familial hypercholesterolemia without pathogenic variants in the studied genes and were analyzed by whole-genome sequencing on the HiSeq 1500 platform (Illumina). The whole-genome sequencing revealed rare variants in three out of five analyzed patients: a heterozygous variant (rs760657350) located in a splicing acceptor site in the PLD1 gene (c.2430-1G>A), a previously undescribed single-nucleotide deletion in the SIDT1 gene [c.2426del (p.Leu809CysfsTer2)], new missense variant c.10313C>G (p.Pro3438Arg) in the LRP1B gene, and single-nucleotide deletion variant rs753876598 [c.165del (p.Ser56AlafsTer11)] in the CETP gene. All these variants were found for the first time in patients with a clinical diagnosis of familial hypercholesterolemia. Variants were identified that may influence the formation of the familial hypercholesterolemia phenotype.

Polygenic Risk, Rare Variants, and Family History: Independent and Additive Effects on Coronary Heart Disease

Background

Genetic factors are not included in prediction models for coronary heart disease (CHD).

Objectives

The authors assessed the predictive utility of a polygenic risk score (PRS) for CHD (defined as myocardial infarction, coronary revascularization, or cardiovascular death) and whether the risks due to monogenic familial hypercholesterolemia (FH) and family history (FamHx) are independent of and additive to the PRS.

Methods

In UK-biobank participants, PRSCHD was calculated using metaGRS, and 10-year risk for incident CHD was estimated using the pooled cohort equations (PCE). The area under the curve (AUC) of the receiver operator curve and net reclassification improvement (NRI) were assessed. FH was defined as the presence of a pathogenic or likely pathogenic variant in LDLR, APOB, or PCSK9. FamHx was defined as a diagnosis of CHD in first-degree relatives. Independent and additive effects of PRSCHD, FH, and FamHx were evaluated in stratified analyses.

Results

In 323,373 participants with genotype data, the addition of PRSCHD to PCE increased the AUC from 0.759 (95% CI: 0.755-0.763) to 0.773 (95% CI: 0.769-0.777). The AUC and NRIEvent for PRSCHD were higher before the age of 55 years. Of 199,997 participants with exome sequence data, 10,000 had a PRSCHD ≥95th percentile (PRSP95), 673 had FH, and 46,163 had FamHx. The CHD risk associated with PRSP95 was independent of FH and FamHx. The risks associated with combinations of PRSCHD, FH, and FamHx were additive and comprehensive estimates could be obtained by multiplying the risk from each genetic factor.

Conclusions

Incorporating PRSCHD into the PCE improves risk prediction for CHD, especially at younger ages. The associations of PRSCHD, FH, and FamHx with CHD were independent and additive.

Impact of providing genetics-based future cardiovascular risk on LDL-C in patients with familial hypercholesterolemia

BACKGROUND

Familial hypercholesterolemia (FH) is an autosomal dominant monogenic disease characterized by high low-density lipoprotein cholesterol (LDL-C) levels. Although carrying causative FH variants is associated with coronary heart disease (CHD), it remains unclear whether disclosing its associated cardiovascular risk affects outcomes in patients with FH.

OBJECTIVE

We aimed to evaluate the efficacy of providing future cardiovascular risk based on genetic testing in addition to a standard FH education program.

METHODS

We conducted a randomized, wait-list controlled, open-label, single-center trial. In the intervention group, we reported a future cardiovascular risk based on the genetic testing adding to standard FH education at week 0. In the wait-list control group, we only disseminated standard FH education according to the guidelines at week 0; they later received a genetic testing-based cardiovascular risk assessment at week 24. The primary endpoint of this study was the plasma LDL-C level at week 24.

RESULTS

Fifty eligible patients with clinically diagnosed FH, without a history of CHD, were allocated to the intervention group (n = 24) or the wait-list control group (n = 26). At week 24, the intervention group had a significantly greater reduction in LDL-C levels than the wait-list control group (mean changes, -13.1 mg/dL vs. 6.6 mg/dL; difference, -19.7 mg/dL; 95% confidence interval, -34 to -5.6; p = 0.009). This interventional effect was consistent with FH causative variant carriers but not with non-carriers.

CONCLUSIONS

In addition to standard FH care, providing future cardiovascular risk based on genetic testing can further reduce plasma LDL-C levels, particularly among FH causal variant carriers.

REGISTRATION

Japan Registry of Clinical Trials (jRCTs04218002). URL: https://jrct.niph.go.jp/latest-detail/jRCTs042180027.

The German CaRe high registry for familial hypercholesterolemia - Sex differences, treatment strategies, and target value attainment

Background and aims

Familial hypercholesterolemia (FH) is among the most common genetic disorders in primary care. However, only 15% or less of patients are diagnosed, and few achieve the goals for low-density lipoprotein cholesterol (LDL-C). In this analysis of the German Cascade Screening and Registry for High Cholesterol (CaRe High), we examined the status of lipid management, treatment strategies, and LDL-C goal attainment according to the ESC/EAS dyslipidemia guidelines.

Methods

We evaluated consolidated datasets from 1501 FH patients diagnosed clinically and seen either by lipid specialists or general practitioners and internists. We conducted a questionnaire survey of both the recruiting physicians and patients.

Results

Among the 1501 patients, 86% regularly received lipid-lowering drugs. LDL-C goals were achieved by 26% and 10% of patients with atherosclerotic cardiovascular disease (ASCVD) according to the 2016 and 2019 ESC/EAS dyslipidemia guidelines, respectively. High intensity lipid-lowering was administered more often in men than in women, in patients with ASCVD, at higher LDL-C and in patients with a genetic diagnosis of FH.

Conclusions

FH is under-treated in Germany compared to guideline recommendations. Male gender, genetic proof of FH, treatment by a specialist, and presence of ASCVD appear to be associated with increased treatment intensity. Achieving the LDL-C goals of the 2019 ESC/EAS dyslipidemia guidelines remains challenging if pre-treatment LDL-C is very high.

Targeting PCSK9 to tackle cardiovascular disease

Lowering blood cholesterol levels efficiently reduces the risk of developing atherosclerotic cardiovascular disease (ASCVD), including coronary artery disease (CAD), which is the main cause of death worldwide. CAD is caused by plaque formation, comprising cholesterol deposits in the coronary arteries. Proprotein convertase subtilisin kexin/type 9 (PCSK9) was discovered in the early 2000s and later identified as a key regulator of cholesterol metabolism. PCSK9 induces lysosomal degradation of the low-density lipoprotein (LDL) receptor in the liver, which is responsible for clearing LDL-cholesterol (LDL-C) from the circulation. Accordingly, gain-of-function PCSK9 mutations are causative of familial hypercholesterolemia, a severe condition with extremely high plasma cholesterol levels and increased ASCVD risk, whereas loss-of-function PCSK9 mutations are associated with very low LDL-C levels and protection against CAD. Since the discovery of PCSK9, extensive investigations in developing PCSK9 targeting therapies have been performed. The combined delineation of clear biology, genetic risk variants, and PCSK9 crystal structures have been major drivers in developing antagonistic molecules. Today, two antibody-based PCSK9 inhibitors have successfully progressed to clinical application and shown to be effective in reducing cholesterol levels and mitigating the risk of ASCVD events, including myocardial infarction, stroke, and death, without any major adverse effects. A third siRNA-based inhibitor has been FDA-approved but awaits cardiovascular outcome data. In this review, we outline the PCSK9 biology, focusing on the structure and nonsynonymous mutations reported in the PCSK9 gene and elaborate on PCSK9-lowering strategies under development. Finally, we discuss future perspectives with PCSK9 inhibition in other severe disorders beyond cardiovascular disease.

[Primary disorders of lipid metabolism: their place in current dyslipidemia guidelines and treatment innovations]

According to current guidelines, the selection and intensity of lipid-effective therapies are based on the risk to be treated. The sole clinical categories of primary and secondary prevention of cardiovascular diseases result in over- and under-treatment, which may be a contributory cause of incomplete implementation of current guidelines in everyday practice. For the extent of benefit in cardiovascular outcome studies with lipid-lowering drugs, the importance of dyslipdemia for the pathogenesis of atherosclerosis-related diseases is crucial. Primary lipid metabolism disorders are characterized by life-long increased exposure to atherogenic lipoproteins. This article describes the relevance of new data for low density lipoprotein-effective therapy: inhibition of proprotein convertase subtilisin/kexin type 9 (PCSK9), adenosine triphosphate (ATP) citrate lyase with bempedoic acid, and ANGPTL3 with special consideration of primary lipid metabolism disorders, which are insufficiently taken into account, or not taken into account at all, in current guidelines. This is due to their apparently low prevalence rate and thus the lack of large outcome studies. The authors also discuss the consequences of increased lipoprotein (a), which cannot be sufficiently reduced until the ongoing intervention studies examining antisense oligonucleotides and small interfering RNA (siRNA) against apolipoprotein (a) are completed. Another challenge in practice is the treatment of rare, massive hypertriglyceridemia, especially with the aim of preventing pancreatitis. For this purpose, the apolipoprotein C3 (ApoC3) antisense oligonucleotide volenasorsen is available, which binds to the mRNA for ApoC3 and lowers triglycerides by around three quarters.

Premature morbidity and mortality associated with potentially undiagnosed familial hypercholesterolemia in the general population

Background

Familial hypercholesterolemia (FH) is common, but underdiagnosed, and few systematic early screening programs exist.

Objective

To assess health outcomes among those with a recorded diagnosis of FH and potential cases of FH with no recorded diagnosis.

Methods

Retrospective cohort study using the UK Clinical Practice Research Datalink. Records of adults were classified as diagnosed FH (FHCoded), or via accepted algorithms using LDL-C and clinical characteristics as potential FH (FHPotential) or unlikely FH (FHUnlikely) using the DLCN or EUROASPIRE criteria (but no record of FH). Outcomes assessed were premature cardiovascular (CV) events, premature deaths and life expectancy.

Results

Among 1,729,046 individuals free from CV events, a record of FHCoded before the age of 40 was 0.3/1000 (IQR 0.3-0.4) and increased with age. Where LDL-C levels were available, 1.8/1000 (IQR 1.6-2.0) could be classified as FHPotential. LDL-C was higher for both FHCoded and FHPotential vs FHUnlikely (185.6 and 216.6 vs 116 mg/dL, respectively, p<0.001). Compared to FHUnlikely both FHCoded and FHPotential cohorts had a higher risk of premature cardiovascular events (both p<0.001) with highest rates among FHCoded. Risk of premature deaths did not differ between FHCoded and FHUnlikely, but was 1.88 (95% CI 1.27-2.78, p = 0.002) for FHPotential vs FHCoded and 2.40 (95% CI 1.57-3.67, p<0.001) for FHPotential vs FHUnlikely. At age 18, the FHPotential cohort had a life expectancy 16 years lower than the FHCoded cohort (p<0.001).

Conclusions

Potential cases of FH had a doubling in risk of premature death and a large reduction in life expectancy compared to individuals with a recorded diagnosis of FH. These findings strengthen the critical importance of identifying potential cases of FH early and early treatment.

Aortic Wall Thickness as a Surrogate for Subclinical Atherosclerosis in Familial and Nonfamilial Hypercholesterolemia: Quantitative 3D Magnetic Resonance Imaging Study and Interrelations with Computed Tomography Calcium Scores, and Carotid Ultrasonography

We aimed to compare the extent of subclinical atherosclerosis in the ascending and descending aortas by measuring wall area and thickness using 3D cardiovascular magnetic resonance imaging (aAWAI and dAWAI) in patients with asymptomatic familial hypercholesterolemia (FH) and nonfamilial hypercholesterolemia (NFH). We also aimed to establish the interrelations of CMR parameters with other subclinical atherosclerosis measurements, such as calcium scores, obtained using computed tomography in coronary arteries (CCS) and ascending and descending aorta (TCSasc and TCSdsc), as well as the carotid intima-media thicknesses (cIMT) using ultrasonography. A total of 60 patients with FH (29 men and 31 women), with a mean age of 52.3 ± 9.6 years, were analyzed. A subclinical atherosclerosis assessment was also performed on a group consisting of 30 age- and gender-matched patients with NFH, with a mean age of 52.5 ± 7.9 years. We found the ascending and descending aortic wall areas and thicknesses in the FH group to be significantly increased than those of the NFH group. A multivariate logistic regression analysis showed that a positive FH mutation value was a strong predictor of high aAWAI and dAWAI independent of the LDL cholesterol level. Correlations across CMR atherosclerotic parameters, calcium scores, and cIMT in the FH and NFH groups, were significant but low. Most of the atherosclerosis tests with high results belonged to the FH group. We found that patients with documented heterozygous FH had a higher atherosclerosis burden in the aorta compared to patients with severe hypercholesterolemia without FH gene mutation. Atherosclerosis is not severe in asymptomatic patients with FH, but is more pronounced and also more diffuse than in patients with NFH. The etiology of hypercholesterolemia, and not just cholesterol levels, plays a significant role in determining the degree of subclinical atherosclerosis.

Genetic Characteristics of Latvian Patients with Familial Hypercholesterolemia: The First Analysis from Genome-Wide Sequencing

BACKGROUND

There is limited data on the genetic characteristics of patients with familial hypercholesterolemia (FH) in Latvia. We aim to describe monogenic variants in patients from the Latvian Registry of FH (LRFH).

METHODS

Whole genome sequencing with 30× coverage was performed in unrelated index cases from the LRFH and the Genome Database of Latvian Population. LDLR, APOB, PCSK9, LDLRAP1, ABCG5, ABCG8, LIPA, LPA, CYP27A1, and APOE genes were analyzed. Only variants annotated as pathogenic (P) or likely pathogenic (LP) using the FH Variant Curation Expert Panel guidelines for LDLR and adaptations for APOB and PCSK9 were reported.

RESULTS

Among 163 patients, the mean highest documented LDL-cholesterol level was 7.47 ± 1.60 mmol/L, and 79.1% of patients had LDL-cholesterol ≥6.50 mmol/L. A total of 15 P/LP variants were found in 34 patients (diagnostic yield: 20.9%): 14 in the LDLR gene and 1 in the APOB gene. Additionally, 24, 54, and 13 VUS were detected in LDLR, APOB, and PCSK9, respectively. No P/LP variants were identified in the other tested genes.

CONCLUSIONS

Despite the high clinical likelihood of FH, confirmed P/LP variants were detected in only 20.9% of patients in the Latvian cohort when assessed with genome-wide next generation sequencing.

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.

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.

High-Throughput Microscopy Characterization of Rare LDLR Variants

Familial hypercholesterolemia (FH) is the most common inherited life-threatening disorder of lipid metabolism. Early diagnosis and treatment are the key to reduce the cumulative life-long cardiovascular burden of patients with FH. The high number of LDLR variants described as variants of unknown significance is the largest obstacle to achieve a definitive FH diagnosis. This study established a time- and cost-effective high-throughput cell-based assay to functionally profile LDLR variants, which allowed us to discriminate disruptive rare variants from silent ones. This work generated a valuable resource for systematic functional characterization of LDLR variants solving 1 of the major issues to achieve a definitive FH diagnosis.

Assessment of cardiovascular disease risk: a 2023 update

PURPOSE OF REVIEW

The aim of this study was to highlight the current best practice for atherosclerotic cardiovascular disease (CVD) risk evaluation, including selective use of adjunctive tools for risk stratification [e.g. coronary artery calcium (CAC) scoring] and risk enhancement [e.g. lipoprotein(a) [Lp(a)], polygenic risk scoring (PRS)].

RECENT FINDINGS

New studies have evaluated the efficacy of various risk assessment tools. These studies demonstrate the role of Lp(a) as a risk-enhancing factor ready for more widespread use. CAC is the gold standard method of assessing subclinical atherosclerosis, enabling true risk stratification of patients, and informing net benefit assessment for initiating or titrating lipid-lowering therapy (LLT).

SUMMARY

Lp(a) concentration and CAC scoring, apart from the traditional risk factors, add the most value to the current CVD risk assessment approaches of all available tools, especially in terms of guiding LLT. In addition to new integrative tools such as the MESA CHD Risk Score and Coronary Age calculator, the future of risk assessment may include PRS and more advanced imaging techniques for atherosclerosis burden. Soon, polygenic risk scoring may be used to identify the age at which to begin CAC scoring, with CAC scores guiding preventive strategies.

Recent advances in the management and implementation of care for familial hypercholesterolaemia

Familial hypercholesterolaemia (FH) is a common autosomal semi-dominant and highly penetrant disorder of the low-density lipoprotein (LDL) receptor pathway, characterised by lifelong elevated levels of low-density lipoprotein cholesterol (LDL-C) and increased risk of atherosclerotic cardiovascular disease (ASCVD). However, many patients with FH are not diagnosed and do not attain recommended LDL-C goals despite maximally tolerated doses of potent statin and ezetimibe. Over the past decade, several cholesterol-lowering therapies such as those targeting proprotein convertase subtilisin/kexin type 9 (PCSK9) or angiopoietin-like 3 (ANGPTL3) with monoclonal antibody or ribonucleic acid (RNA) approaches have been developed that promise to close the treatment gap. The availability of new therapies with complementary modes of action of lipid metabolism has enabled many patients with FH to attain guideline-recommended LDL-C goals. Emerging therapies for FH include liver-directed gene transfer of the LDLR, vaccines targeting key proteins involved in cholesterol metabolism, and CRISPR-based gene editing of PCSK9 and ANGPTL3, but further clinical trials are required. In this review, current and emerging treatment strategies for lowering LDL-C, and ASCVD risk-stratification, as well as implementation strategies for the care of patients with FH are reviewed.

Longitudinal Trends in Severe Dyslipidemia in the Czech Population: The Czech MONICA and Czech Post-MONICA Study

Background: Severe hypercholesterolemia is associated with an increase in the risk of developing atherosclerotic cardiovascular disease. The aim of this analysis was to assess longitudinal trends in severe dyslipidemia (defined as total cholesterol > 8 mmol/L or LDL-cholesterol > 5 mmol/L) in a representative population sample of the Czech Republic and to analyze the longitudinal trends in the basic characteristics of individuals with severe dyslipidemia. Methods: Seven independent cross-sectional surveys were organized in the Czech Republic to screen for major cardiovascular risk factors (from 1985 to 2015-2018). A total of 20,443 randomly selected individuals aged 25-64 years were examined. Results: The overall prevalence of severe dyslipidemia was 6.6%, with a significant downward trend from the fifth survey onwards (2000/2001). Over the study period of 30+ years, the individuals with severe dyslipidemia became older, increased in BMI, and did not change their smoking habits. Total cholesterol and non-HDL-cholesterol decreased significantly in both sexes throughout the duration of the study. Conclusions: Despite a significant improvement in lipids in the Czech Republic from 1985, substantially contributing to the decline in cardiovascular mortality, the number of individuals with severe dyslipidemia remained high, and in most cases, they were newly detected during our screening examinations and were thus untreated.

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.

Screening for Lipid Disorders in Children and Adolescents: US Preventive Services Task Force Recommendation Statement

Importance

Familial hypercholesterolemia and multifactorial dyslipidemia are 2 conditions that cause abnormally high lipid levels in children, which can lead to premature cardiovascular events (eg, myocardial infarction and stroke) and death in adulthood.

Objective

The US Preventive Services Task Force (USPSTF) commissioned a systematic review to evaluate the benefits and harms of screening for lipid disorders in asymptomatic children and adolescents.

Population

Asymptomatic children and adolescents 20 years or younger without a known diagnosis of a lipid disorder.

Evidence Assessment

The USPSTF concludes that the current evidence is insufficient and the balance of benefits and harms for screening for lipid disorders in asymptomatic children and adolescents 20 years or younger cannot be determined.

Recommendation

The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for lipid disorders in children and adolescents 20 years or younger. (I statement).