Diagnostic et traitement des hypercholestérolémies familiales (HF) chez l’adulte : recommandations de la Nouvelle société française d’athérosclérose (NSFA)

A new 165-SNP low-density lipoprotein cholesterol polygenic risk score based on next generation sequencing outperforms previously published scores in routine diagnostics of familial hypercholesterolemia

Genetic diagnosis of familial hypercholesterolemia (FH) remains unexplained in 30 to 70% of patients after exclusion of monogenic disease. There is now a growing evidence that a polygenic burden significantly modulates LDL-cholesterol (LDL-c) concentrations. Several LDL-c polygenic risk scores (PRS) have been set up. However, the balance between their diagnosis performance and their practical use in routine practice is not clearly established. Consequently, we set up new PRS based on our routine panel for sequencing and compared their diagnostic performance with previously-published PRS. After a meta-analysis, four new PRS including 165 to 1633 SNP were setup using different softwares. They were established using two French control cohorts (MONA LISA n=1082 and FranceGenRef n=856). Then the explained LDL-c variance and the ability of each PRS to discriminate monogenic negative FH patients (M-) versus healthy controls were compared with 4 previously-described PRS in 785 unrelated FH patients. Between all PRS, the 165-SNP PRS developed with PLINK showed the best LDL-c explained variance (adjusted R²=0.19) and the best diagnosis abilities (AUROC=0.77, 95%CI=0.74-0.79): it significantly outperformed all the previously-published PRS (p<1 × 10^-4). By using a cut-off at the 75th percentile, 61% of M- patients exhibited a polygenic hypercholesterolemia with the 165-SNP PRS versus 48% with the previously published 12-SNP PRS (p =3.3 × 10^-6). These results were replicated using the UK biobank. This new 165-SNP PRS, usable in routine diagnosis, exhibits better diagnosis abilities for a polygenic hypercholesterolemia diagnosis. It would be a valuable tool to optimize referral for whole genome sequencing.

Lipoprotein(a): Pathophysiology, measurement, indication and treatment in cardiovascular disease. A consensus statement from the Nouvelle Société Francophone d'Athérosclérose (NSFA)

Lipoprotein(a) is an apolipoprotein B100-containing low-density lipoprotein-like particle that is rich in cholesterol, and is associated with a second major protein, apolipoprotein(a). Apolipoprotein(a) possesses structural similarity to plasminogen but lacks fibrinolytic activity. As a consequence of its composite structure, lipoprotein(a) may: (1) elicit a prothrombotic/antifibrinolytic action favouring clot stability; and (2) enhance atherosclerosis progression via its propensity for retention in the arterial intima, with deposition of its cholesterol load at sites of plaque formation. Equally, lipoprotein(a) may induce inflammation and calcification in the aortic leaflet valve interstitium, leading to calcific aortic valve stenosis. Experimental, epidemiological and genetic evidence support the contention that elevated concentrations of lipoprotein(a) are causally related to atherothrombotic risk and equally to calcific aortic valve stenosis. The plasma concentration of lipoprotein(a) is principally determined by genetic factors, is not influenced by dietary habits, remains essentially constant over the lifetime of a given individual and is the most powerful variable for prediction of lipoprotein(a)-associated cardiovascular risk. However, major interindividual variations (up to 1000-fold) are characteristic of lipoprotein(a) concentrations. In this context, lipoprotein(a) assays, although currently insufficiently standardized, are of considerable interest, not only in stratifying cardiovascular risk, but equally in the clinical follow-up of patients treated with novel lipid-lowering therapies targeted at lipoprotein(a) (e.g. antiapolipoprotein(a) antisense oligonucleotides and small interfering ribonucleic acids) that markedly reduce circulating lipoprotein(a) concentrations. We recommend that lipoprotein(a) be measured once in subjects at high cardiovascular risk with premature coronary heart disease, in familial hypercholesterolaemia, in those with a family history of coronary heart disease and in those with recurrent coronary heart disease despite lipid-lowering treatment. Because of its clinical relevance, the cost of lipoprotein(a) testing should be covered by social security and health authorities.

Screening and treatment of familial hypercholesterolemia in a French sample of ambulatory care patients: A retrospective longitudinal cohort study

Background and aims

Untreated Familial Hypercholesterolemia (FH) leads to premature morbidity and mortality. In France, its epidemiology and management are understudied in ambulatory care. We described the clinical profile, pharmacological management, and clinical outcomes in a French sample of FH patients.

Methods

This was a retrospective longitudinal study on patients from The Health Improvement Network (THIN^®) database in France, between October 2016-June 2019. Patients ≥18 years, with probable/definite FH based on the Dutch Lipid Clinic Network (DLCN) criteria were included. Baseline characteristics, lipid profile, lipid-lowering therapy (LLT), low-density lipoprotein-cholesterol (LDL-C) goal achievement; and disease management at 6-month of follow-up were analyzed.

Results

116 patients with probable (n = 70)/definite (n = 46) FH were included (mean age:57.8±14.0 years; 56.0% women; 9.5% with personal history of cardiovascular events); 90 patients had data available at follow-up. At baseline, 77.6% of patients had LDL-C>190 mg/dL, 27.6% were not receiving LLTs, 37.9% received statins alone, 20.7% statins with other LLTs, and 7.7% other LLTs. High-intensity statins were prescribed to 11.2% of patients, 30.2% received moderate-intensity statins, and 8.6% low-intensity statins. Only 6.0% of patients achieved LDL-C goal. At 6-month of follow-up, statins discontinuation and switching were 22.7% and 2.3%, respectively. None of the patients received proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors at baseline nor follow-up.

Conclusions

Despite the existence of effective LLTs, FH patients are suboptimally-treated, do not achieve LDL-C goal, and exhibit worsened pharmacological management over time. Future studies with longer follow-up periods and assessment of factors affecting LDL-C management, including lifestyle and diet, are needed.

Reducing the Clinical and Public Health Burden of Familial Hypercholesterolemia: A Global Call to Action

Importance

Familial hypercholesterolemia (FH) is an underdiagnosed and undertreated genetic disorder that leads to premature morbidity and mortality due to atherosclerotic cardiovascular disease. Familial hypercholesterolemia affects 1 in 200 to 250 people around the world of every race and ethnicity. The lack of general awareness of FH among the public and medical community has resulted in only 10% of the FH population being diagnosed and adequately treated. The World Health Organization recognized FH as a public health priority in 1998 during a consultation meeting in Geneva, Switzerland. The World Health Organization report highlighted 11 recommendations to address FH worldwide, from diagnosis and treatment to family screening and education. Research since the 1998 report has increased understanding and awareness of FH, particularly in specialty areas, such as cardiology and lipidology. However, in the past 20 years, there has been little progress in implementing the 11 recommendations to prevent premature atherosclerotic cardiovascular disease in an entire generation of families with FH.

Observations

In 2018, the Familial Hypercholesterolemia Foundation and the World Heart Federation convened the international FH community to update the 11 recommendations. Two meetings were held: one at the 2018 FH Foundation Global Summit and the other during the 2018 World Congress of Cardiology and Cardiovascular Health. Each meeting served as a platform for the FH community to examine the original recommendations, assess the gaps, and provide commentary on the revised recommendations. The Global Call to Action on Familial Hypercholesterolemia thus represents individuals with FH, advocacy leaders, scientific experts, policy makers, and the original authors of the 1998 World Health Organization report. Attendees from 40 countries brought perspectives on FH from low-, middle-, and high-income regions. Tables listing country-specific government support for FH care, existing country-specific and international FH scientific statements and guidelines, country-specific and international FH registries, and known FH advocacy organizations around the world were created.

Conclusions and Relevance

By adopting the 9 updated public policy recommendations created for this document, covering awareness; advocacy; screening, testing, and diagnosis; treatment; family-based care; registries; research; and cost and value, individual countries have the opportunity to prevent atherosclerotic heart disease in their citizens carrying a gene associated with FH and, likely, all those with severe hypercholesterolemia as well.

Long-term outcomes after acute myocardial infarction in patients with familial hypercholesterolemia: The French registry of Acute ST-elevation and non-ST-elevation Myocardial Infarction program

BACKGROUND

Patients with familial hypercholesterolemia (FH) are prone to develop acute myocardial infarction (AMI) at a younger age.

OBJECTIVES

The aim of the present study was to assess 5-year outcomes after AMI according to the presence of FH in a large multicenter cohort of patients.

METHODS

The French registry of Acute ST-elevation and non-ST-elevation Myocardial Infarction consists of nationwide surveys recruiting patients over a 1- to 2-month period every 5 years. Patients recruited in 2005 and 2010 were followed up to 5 years.

RESULTS

Of 5147 patients discharged alive and in whom FH status could be assessed, 2.8% had probable/definite FH, using an adapted Dutch Lipid Clinic score. They were 12 years younger, on average, than non-FH patients. Before adjustment, their 5-year survival and event-free survival did not differ from non-FH patients. After adjustment, however, both mortality (hazard ratio [HR] 1.82, 95% confidence interval [CI] 1.15-2.89; P = .011) and the combined endpoint of death, AMI, or stroke (HR 2.22, 95% CI: 1.51-3.26; P < .001) were higher in FH patients. The higher risk in FH patients was also present in patients receiving high-intensity lipid-lowering therapy at discharge: adjusted HR for mortality 2.29, 95% CI: 1.18 to 4.47, P = .015; HR for cardiovascular events 2.57, 95% CI: 1.48 to 4.48, P = .001. Concordant results were observed in propensity score-marched cohorts.

CONCLUSIONS

The risk of long-term mortality and cardiovascular events is twice as high in FH than in non-FH patients, when adjusted on baseline characteristics, even for those receiving high-intensity lipid-lowering therapy. Additional therapeutic measures are needed in these patients.

Overview of the current status of familial hypercholesterolaemia care in over 60 countries - The EAS Familial Hypercholesterolaemia Studies Collaboration (FHSC)

BACKGROUND AND AIMS

Management of familial hypercholesterolaemia (FH) may vary across different settings due to factors related to population characteristics, practice, resources and/or policies. We conducted a survey among the worldwide network of EAS FHSC Lead Investigators to provide an overview of FH status in different countries.

METHODS

Lead Investigators from countries formally involved in the EAS FHSC by mid-May 2018 were invited to provide a brief report on FH status in their countries, including available information, programmes, initiatives, and management.

RESULTS

63 countries provided reports. Data on FH prevalence are lacking in most countries. Where available, data tend to align with recent estimates, suggesting a higher frequency than that traditionally considered. Low rates of FH detection are reported across all regions. National registries and education programmes to improve FH awareness/knowledge are a recognised priority, but funding is often lacking. In most countries, diagnosis primarily relies on the Dutch Lipid Clinics Network criteria. Although available in many countries, genetic testing is not widely implemented (frequent cost issues). There are only a few national official government programmes for FH. Under-treatment is an issue. FH therapy is not universally reimbursed. PCSK9-inhibitors are available in ∼2/3 countries. Lipoprotein-apheresis is offered in ∼60% countries, although access is limited.

CONCLUSIONS

FH is a recognised public health concern. Management varies widely across countries, with overall suboptimal identification and under-treatment. Efforts and initiatives to improve FH knowledge and management are underway, including development of national registries, but support, particularly from health authorities, and better funding are greatly needed.

[PCSK9 inhibitors: What place in the management of dyslipidemia?]

PCSK9 protein is a key regulator of LDL receptor activity. Gain-of-function mutations in PCSK9 are one of the genetic causes of familial hypercholesterolemia. Conversely, loss-of-function mutations are associated with lower levels of LDL cholesterol and reduced coronary heart disease. Monoclonal antibodies targeting PCSK9 are highly efficacious in lowering LDL-C levels, with a good tolerability and safety profile. Two PCSK9 inhibitors, alirocumab and evolocumab, have demonstrated a cardiovascular benefit in addition to statin therapy in patients with established cardiovascular disease. A recent European consensus has defined the candidates for PCSK9 inhibitors, e.g., patients with established cardiovascular disease and patients with familial hypercholesterolemia in primary prevention, with substantially elevated LDL-C levels despite maximally tolerated statin with or without ezetimibe therapy.

[Screening for familial hypercholesterolemia from low-density lipoprotein cholesterol levels at admission in the coronary care unit]

BACKGROUND

Familial hypercholesterolemia (FH) is a frequent genetic disorder that leads to premature atherosclerosis and coronary artery disease. However, knowledge of FH by cardiologists is weak, and FH remains underdiagnosed in France. FH should be suspected when low-density lipoprotein cholesterol (LDLc) levels exceed 1.9g/L (4.9mmol/L) without lipid lowering therapy.

PURPOSE

This multicenter retro- and prospective observational study aimed at estimating the prevalence of high LDLc levels in patients admitted in coronary care units, and the impact for the personal and familial follow-up for lipid status.

METHODS

Retrospective analysis of all plasma lipid measurements performed at admission in coronary care unit of 4 hospitals in 2017. Retrospective analyses of demographic, clinical, and coronary data of consecutive patients with LDLc levels≥1.9g/L. Prospective 1 year follow-up focused on lipid levels, treatments, and personal and familial screening for FH.

RESULTS

Lipid measurement has been performed in 2172 consecutive patients, and 108 (5%) had LDLc level≥1.9g/L (mean age 64±14 years, men 51%). The primary cause of the hospitalisation was acute coronary syndrome (78%), and 22% of patients were free off coronary artery disease. Lipid lowering therapy was present in 9% of patients at admission, and 84% at discharge, with high statins regimen. At 1-year follow-up, control of LDLc level was not performed in 20% of patients, and statin dose was decreased (36%) or withdrawn (7%) in 43%. Lipid measurement has been performed in at least one first degree relative in 37% of patients, and genetic exploration has been done for 3 patients.

CONCLUSIONS

Screening of FH in CCU should be routinely performed using the Dutch Score when LDLc is above 1.9g/L. Individual and familial management of patients at high risk for FH screened in CCU should be optimized, both for diagnosis and therapeutic purposes.

[Familial hypercholesterolemia: An under-diagnosed and under-treated disease. Survey of 495 physicians]

INTRODUCTION

Heterozygous familial hypercholesterolemia (FH) is one of the most frequent genetic diseases with a prevalence of 1/250. It is characterized by a very high cholesterol level since birth and is often complicated by cardiovascular diseases (CV) in young patients. While early diagnosis and appropriate therapeutic management can avoid CV complications, HF is largely under-diagnosed and therefore under-treated.

METHODS

To investigate the management of HF in France, we conducted a survey with 495 general practitioners (n=200) and specialists (n=295).

RESULTS

The results revealed: a large underestimation of the CV risk and a high therapeutic inertia in the management of the affected patients. The practitioners reported a real need for more information about the disease.

CONCLUSION

Given the high frequency of HF and the associated cardiovascular morbidity and mortality, general practitioners have a decisive role to play for the identification and the management of these patients. The recent publication of HAS recommendations on family screening procedures and care of HF patients should improve the management of this disease.

Familial hypercholesterolemia in very young myocardial infarction

Familial hypercholesterolemia (FH) is one of the most common causes of premature myocardial infarction (MI). However, The patterns of FH remained unrecognized in clinical care, especially in very young patients (VYPs, ≤35 years) with MI. The present study enrolled a total of 1,093 VYPs (≤35 years) presenting a first MI. Clinical diagnosis of FH was made using Dutch Lipid Clinic Network criteria. Coronary severity was assessed by Gensini score (GS). Patients were followed for a median of 40-months with cardiac death, stroke, MI, post-discharge revascularization or unstable angina as primary endpoints. The detected rates of definite/probable FH were 6.5%. The prevalence reached up to 10.3% in patients ≤25 years. The FH had similar levels of comorbidities but was younger, more likely to be very high risk (VHR) and had higher GS (p < 0.05) than unlikely FH. Notably, the FH on prior lipid-lowering medication presented a lower GS compared to those untreated. Differences in event rates were similar in FH as unlikely FH (11.8% vs. 8.1%, adjusted hazard ratio 1.35 [0.64–2.86], p = 0.434) but patients on treatment improved outcome (6.5% vs. 10.5%, adjusted hazard ratio 0.35[0.13–0.95], p = 0.039). The early identification and treatment might be critical to reduce cardiovascular risk in VYPs with MI.

Familial hypercholesterolemia: experience from France

PURPOSE OF REVIEW

We provide an overview of molecular diagnosis for familial hypercholesterolemia in France including descriptions of the mutational spectrum, polygenic susceptibility and perspectives for improvement in familial hypercholesterolemia diagnosis.

RECENT FINDINGS

Molecular testing for familial hypercholesterolemia is recommended for patients with a LDL-cholesterol level above 190 mg/dl (adults) associated with criteria related to personal and family history of hypercholesterolemia and premature cardiovascular disease. Among the 3381 index cases included with these characteristics in the French registry for familial hypercholesterolemia, 2054 underwent molecular diagnosis and 1150 (56%) were found to have mutations (93.5% in LDL Receptor (LDLR), 4.7% in apolipoprotein B and 1.8% in Proprotein convertase subtilisin/kexin type 9). A total of 416 different pathogenic variants were found in the LDLR gene. Based on gene score calculation, a polygenic origin may be suggested in 36% of nonmutated patients. Involvement of genetic counselors and education of healthcare professionals for genetics of familial hypercholesterolemia are underway with the aim of improving the efficiency of the diagnosis.

SUMMARY

Genetic cascade screening for familial hypercholesterolemia is currently implemented in France with the complexity to address the diversity of its molecular cause in index cases. Optimization of patient care pathways is critical to improve both the rate of diagnosis and the management of familial hypercholesterolemia patients.

Beyond cascade screening: detection of familial hypercholesterolaemia at childhood immunization and other strategies

PURPOSE OF REVIEW

Familial hypercholesterolaemia is a common genetic disorder that accelerates premature coronary heart disease. Although effective treatments are available, the majority of individuals remain undiagnosed. We review new evidence for improving the detection of familial hypercholesterolaemia.

RECENT FINDINGS

Recent studies have demonstrated that universal screening of children for familial hypercholesterolaemia may be highly effective at the time of immunization if combined with reverse cascade testing of adult family members, who have a more immediate risk of a coronary event. Alerts on laboratory reports and the application of bioinformatics to electronic health records may also be useful for identifying familial hypercholesterolaemia in community settings. Effective detection, diagnosis, and codification of familial hypercholesterolaemia are essential for the development of registries.

SUMMARY

Although the cost-effectiveness of screening programs for familial hypercholesterolaemia in childhood remains to be established, combining universal and reverse cascade screening, complemented by opportunistic identification of individuals in high-risk settings, use of laboratory alerts, and screening of electronic health records are likely to have a high yield in the detection of familial hypercholesterolaemia in the community.

Knowns and unknowns in the care of pediatric familial hypercholesterolemia

Familial hypercholesterolemia (FH) is a common genetic disorder that causes elevated LDL cholesterol levels from birth. Untreated FH accelerates atherosclerosis and predisposes individuals to premature coronary artery disease (CAD) in adulthood. Mendelian randomization studies have demonstrated that LDL cholesterol has both a causal and cumulative effect on the risk of CAD. This supports clinical recommendations that children with FH commence pharmacological treatment from the age of 8 to 10 years, to reduce the burden of hypercholesterolemia. Worldwide, the majority of children with FH remain undiagnosed. Recent evidence suggests that the frequency of FH is at least 1 in 250 and this constitutes a public health issue. We review and identify the knowns and unknowns concerning the detection and management of pediatric FH that impact on the developing model of care for this condition.

[Familial hypercholesterolemia: A largely underestimated cardiovascular risk]

BACKGROUND

Familial hypercholesterolemia is a monogenic autosomal dominant dyslipidemia characterized by a permanent and isolated increase of cholesterol carried by low-density lipoproteins. The prevalence of its heterozygous form is estimated between 1/500 and 1/250, and in the absence of specific treatment, this form is responsible for an increase by a factor of 13 of the risk of premature coronary artery disease compared to patients non-affected by the disease.

OBJECTIVES

To perform an inventory of the knowledge of heterozygous familial hypercholesterolemia in France for physicians involved in the management of the disease.

METHODS

A survey was conducted (by phone and internet) among a representative sample of 495 physicians (cardiologists, endocrinologists/diabetologists, gynecologists, general practitioners) who, in parallel, completed 579 patient records.

RESULTS

Thirty-two percent (95% CI [27.8; 36.2]) of physicians reported the difference between polygenic hypercholesterolemia and familial hypercholesterolemia. The presence of tendinous xanthomas, a key element of diagnosis, was spontaneously mentioned by 44% (95% CI [34; 54.2]) of cardiologists. Six percent (95% CI [2.2; 12.6]) of them gave a correct estimate of the prevalence of familial hypercholesterolemia. The likelihood of transmission of heterozygous familial hypercholesterolemia, when one parent is affected, was known for 59% (95% CI [48.7; 68.7]) of surveyed cardiologists. A cascade screening was performed systematically by 4% (95% CI [1.1; 9.9]) of them. Eighteen percent (95% CI [11; 26.9]) of cardiologists gave an accurate estimation of cardiovascular risk of heterozygous familial hypercholesterolemia. Fifty-seven percent (95% CI [46.7; 66.8]) of cardiologists admitted being misinformed about the heterozygous familial hypercholesterolemia and 83% (95% CI [74.1; 89.7]) expressed a need for information about this disease.

CONCLUSION

The lack of knowledge of heterozygous familial hypercholesterolemia and its associated cardiovascular risk is probably the cause of a diagnostic default leading to inappropriate management of this disease.

Severe dyslipidemia in pregnancy: The role of therapeutic apheresis

During pregnancy physiological changes occur in the lipid metabolism due to changing hormonal conditions: the LDL cholesterol (LDL-C), triglycerides (TG) and lipoprotein(a) [Lp(a)] increase throughout pregnancy. Common lipoprotein disorders are associated in pregnancy with two major clinical disorders: severe hypertriglyceridemia (SHTG) is a potent risk factor for development of acute pancreatitis and elevated cholesterol due to greater concentrations of LDL and remnant lipoproteins and reduced levels of HDL promote atherosclerosis. The combination of homozygous Familial Hypercholesterolemia (HoFH) and pregnancy can be a fatal condition. Therapeutic plasma exchange (TPE) may be used for an urgent need of a fast and effective lowering of TG levels in order to prevent a severe pancreatitis episode or hypertriglyceridemia-induced complications during pregnancy. LDL apheresis can decrease LDL-C and prevent complications and can be considered in the treatment of pregnancies complicated by high LDL-C. These conditions are configured in patients with HeFH who were taking statins before pregnancy (selected cases), patients already receiving apheresis before pregnancy suffering from HoFH, patients suffering from hypertriglyceridemia due to familial hyperlipoproteinemia types I and V, and cases of hypertriglyceridemia secondary to diabetes.