Predictors of cardiovascular events after one year of molecular screening for Familial hypercholesterolemia

Sex differences in treatment of familial hypercholesterolaemia: a meta-analysis

BACKGROUND AND AIMS

Familial hypercholesterolaemia (FH) is a highly prevalent monogenic disorder characterized by elevated LDL cholesterol (LDL-C) levels and premature atherosclerotic cardiovascular disease. Sex disparities in diagnosis, lipid-lowering therapy, and achieved lipid levels have emerged worldwide, resulting in barriers to care in FH. A systematic review was performed to investigate sex-related disparities in treatment, response, and lipid target achievement in FH (PROSPERO, CRD42022353297).

METHODS

MEDLINE, Embase, The Cochrane library, PubMed, Scopus, PsycInfo, and grey literature databases were searched from inception to 26 April 2023. Records were eligible if they described sex differences in the treatment of adults with FH.

RESULTS

Of 4432 publications reviewed, 133 met our eligibility criteria. In 16 interventional clinical trials (eight randomized and eight non-randomized; 1840 participants, 49.4% females), there were no differences between males and females in response to fixed doses of lipid-lowering therapy, suggesting that sex was not a determinant of response. Meta-analysis of 25 real-world observational studies (129 441 participants, 53.4% females) found that females were less likely to be on lipid-lowering therapy compared with males (odds ratio .74, 95% confidence interval .66-.85). Importantly, females were less likely to reach an LDL-C < 2.5 mmol/L (odds ratio .85, 95% confidence interval .74-.97). Similarly, treated LDL-C levels were higher in females. Despite this, male sex was associated with a two-fold greater relative risk of major adverse cardiovascular events including myocardial infarction, atherosclerotic cardiovascular disease, and cardiovascular mortality.

CONCLUSIONS

Females with FH were less likely to be treated intensively and to reach guideline-recommended LDL-C targets. This sex bias represents a surmountable barrier to clinical care.

Association Between Familial Hypercholesterolemia and Risk of Cardiovascular Events and Death in Different Cohorts: A Meta-Analysis of 1.1 Million Subjects

Background and Aims

The association of familial hypercholesterolemia (FH) with risk of cardiovascular events (CVE) and death in different cohorts is controversial. We aimed to assess the risk of CVE and death in patients with FH in different cohorts, including CHD and ACS patients, White and Asian, different diagnostic criteria.

Methods

We searched PubMed, MEDLINE, and Web of Science electronic databases through May 2021 to identify cohort studies of CVE and death in patients with FH.

Results

We found 18 eligible studies with 1,139,788 participants, including 34,261 patients. There were 31,287 ACS patients, of whom 2,338 were combined with FH. Randomized-effects meta-analysis showed that in patients with FH, relative risk (RR) of CVE and death was 1.87 (95% CI 1.21–2.88), among which CVE was 2.14 (95%CI 1.26–3.64), all-cause of death RR = 1.12 (95% CI 0.89–1.41), and cardiac death RR = 1.03 (95% CI 0.59–1.79). Risk of CVE and death in general population with FH was 2.85 (95% CI 0.72–11.21), hyperlipidemia population RR = 1.59 (95% CI 1.05–2.41), coronary heart disease patients (CHD) RR = 1.46 (95% CI 1.24–1.72), and acute coronary syndrome patients (ACS) RR = 1.71 (95% CI 1.19–2.46). Among ACS patients, the RR of CVE in patients with FH was 1.91 (95% CI 1.55–2.35), the RR of all-cause of death was 1.03 (95% CI 0.80–1.32), and the RR of cardiac death was 1.03 (95% CI 0.59–1.79). The risk of CVE and death in ACS patients with FH in White was 1.69 (95% CI 1.09–2.64) and Asian 1.90 (95% CI 1.31–2.75). RR in patients with Dutch Lipid Network criteria (DLCN) ≥6 vs. <3 points was higher (RR = 2.24, 95% CI 1.69–2.97). RR for long-term follow-up was 1.68 (95% CI 1.09–2.61) and for short-term follow-up was 1.80 (95% CI 1.16–2.78). The results of the overall population were similar, but RR for overall population during a short-term follow-up was 1.49 (95% CI 0.81–2.73). We followed PRISMA checklist to complete meta-analysis.

Conclusions

The risk of CVE and death was increased in patients with CHD, especially in patients with ACS. DLCN ≥ 6 points was suggested for clinical diagnosis of FH. The risk of long-term and short-term CVE and death increased in ACS patients with FH.

Registration Number

INPLASY2021110010.

Assessment of Associations Between Serum Lipoprotein (a) Levels and Atherosclerotic Vascular Diseases in Hungarian Patients With Familial Hypercholesterolemia Using Data Mining and Machine Learning

Background and aims: Premature mortality due to atherosclerotic vascular disease is very high in Hungary in comparison with international prevalence rates, though the estimated prevalence of familial hypercholesterolemia (FH) is in line with the data of other European countries. Previous studies have shown that high lipoprotein(a)- Lp(a) levels are associated with an increased risk of atherosclerotic vascular diseases in patients with FH. We aimed to assess the associations of serum Lp(a) levels and such vascular diseases in FH using data mining methods and machine learning techniques in the Northern Great Plain region of Hungary.

Methods: Medical records of 590,500 patients were included in our study. Based on the data from previously diagnosed FH patients using the Dutch Lipid Clinic Network scores (≥7 was evaluated as probable or definite FH), we trained machine learning models to identify FH patients.

Results: We identified 459 patients with FH and 221 of them had data available on Lp(a). Patients with FH had significantly higher Lp(a) levels compared to non-FH subjects [236 (92.5; 698.5) vs. 167 (80.2; 431.5) mg/L, p < .01]. Also 35.3% of FH patients had Lp(a) levels >500 mg/L. Atherosclerotic complications were significantly more frequent in FH patients compared to patients without FH (46.6 vs. 13.9%). However, contrary to several other previous studies, we could not find significant associations between serum Lp(a) levels and atherosclerotic vascular diseases in the studied Hungarian FH patient group.

Conclusion: The extremely high burden of vascular disease is mainly explained by the unhealthy lifestyle of our patients (i.e., high prevalence of smoking, unhealthy diet and physical inactivity resulting in obesity and hypertension). The lack of associations between serum Lp(a) levels and atherosclerotic vascular diseases in Hungarian FH patients may be due to the high prevalence of these risk factors, that mask the deleterious effect of Lp(a).

Past, Present, and Future of Familial Hypercholesterolemia Management

Familial hypercholesterolemia (FH) is a monogenic form of severe hypercholesterolemia that, if left untreated, is associated with early onset of atherosclerosis. FH derives from genetic variants that lead to inefficient hepatic clearance of low-density lipoprotein (LDL) particles from the circulation. The FH phenotype is encountered in approximately 1 of every 300 people. The risk of atherosclerotic cardiovascular disease (ASCVD) is higher in those with FH than in normolipidemic individuals and in those with polygenic hypercholesterolemia. FH is usually diagnosed by clinical scores that consider hypercholesterolemia, family history of early ASCVD and hypercholesterolemia, and cutaneous stigmata. Genetic diagnosis is important and should be offered to individuals suspected of FH. Family cascade screening is important to identify asymptomatic hypercholesterolemic individuals. Despite the high risk of ASCVD, this risk is heterogenous in heterozygous FH and depends not only on high LDL cholesterol (LDL-C) but also on other risk biomarkers. Risk can be evaluated by considering biomarkers such as male sex, late-onset therapy (> age 40), LDL-C > 310 mg/dL, low high-density lipoprotein cholesterol, elevated lipoprotein(a), obesity, diabetes, and hypertension by using specific risk equations and by detecting subclinical coronary atherosclerosis. Statins are the main therapy for FH and change the natural history of ASCVD; however, most individuals persist with elevated LDL-C. PCSK9 inhibitors provide robust and safe LDL-C lowering in FH, although elevated costs preclude their widespread use. Newer therapies such as ANGPTL3 inhibitors add intensive LDL-C lowering for refractory forms of FH. Finally, while it is possible to normalize LDL-C in people with FH, the disease unfortunately is still severely underdiagnosed and undertreated.

Familial Hypercholesterolemia: Do HDL Play a Role?

Cardiovascular disease (CVD) in heterozygous familial hypercholesterolemia (HeFH), the most frequent monogenic disorder of human metabolism, is largely driven by low-density lipoprotein (LDL) cholesterol concentrations. Since the CVD rate differs considerably in this population, beyond the lifetime LDL cholesterol vascular accumulation, other classical risk factors are involved in the high cardiovascular risk of HeFH. Among other lipoprotein disturbances, alterations in the phenotype and functionality of high-density lipoproteins (HDL) have been described in HeFH patients, contributing to the presence and severity of CVD. In fact, HDL are the first defensive barrier against the burden of high LDL cholesterol levels owing to their contribution to reverse cholesterol transport as well as their antioxidant and anti-inflammatory properties, among others. In this context, the present narrative review aimed to focus on quantitative and qualitative abnormalities in HDL particles in HeFH, encompassing metabolic, genetic and epigenetic aspects.

Familial hypercholesterolemia and vulnerability of coronary plaque in patients with coronary artery disease

Objectives

Patients with familial hypercholesterolemia (FH) are at a very high risk of coronary artery diseases. The aim of the present study was to clarify the characteristics of coronary plaque in patients with FH.

Design

and Methods: A total of 569 patients who underwent optical coherence tomography (OCT) imaging of culprit plaque were included. The characteristics of culprit plaque were compared between patients with and without FH.

Results

A total of 38 patients (6.7%) were clinically diagnosed with FH. The location of the culprit plaque was significantly different (p ​< ​0.001) with a trend toward higher frequency of left main lesion in the FH group than in the group with no FH (7.9 vs. 0%). Culprit plaque was significantly shorter in patients with FH than those without FH (28.1 vs. 33.2 ​mm, p ​= ​0.016). A trend toward higher prevalence of plaque with macrophage accumulation in patients with FH than those without FH (50.0 vs. 34.7%, p ​= ​0.056) was observed, although the prevalence of other vulnerable characteristics including thin-cap fibroatheroma (TCFA) was comparable between patients with and without FH. Among patients with FH, significant increases in the prevalence of lipid-rich plaque (p ​= ​0.028) and TCFA (p ​= ​0.003) were observed according to the increase in low-density lipoprotein cholesterol (LDL-C) levels.

Conclusions

Patients with FH had shorter culprit plaque without significant difference in the prevalence of vulnerable plaque components compared with patients without FH. A higher LDL-C level was associated with higher prevalence of vulnerable plaque in patients with FH.

Subclinical coronary atherosclerosis and cardiovascular risk stratification in heterozygous familial hypercholesterolemia patients undergoing statin treatment

PURPOSE OF REVIEW

To discuss the heterogeneity of atherosclerotic cardiovascular disease (ASCVD) risk in heterozygous familial hypercholesterolemia and evidence and limitations of clinical risk scores and subclinical coronary atherosclerosis (SCA) imaging to evaluate risk.

RECENT FINDINGS

Risk evaluation in contemporary familial hypercholesterolemia cohorts needs to consider the cause of the familial hypercholesterolemia phenotype, for example the presence of autosomal molecular defects that impart a greater ASCVD risk than in polygenic hypercholesterolemia, prospective follow-up and the impact of statin treatment. As atherosclerosis is multifactorial, clinical scores like the Montreal familial hypercholesterolemia score and SAFEHEART risk equation have been proposed to stratify ASCVD in statin-treated, molecularly defined familial hypercholesterolemia individuals. However, these scores need further validation. SCA distribution in familial hypercholesterolemia individuals undergoing conventional lipid-lowering treatment is heterogeneous, with 45-50% of individuals not presenting any coronary artery calcification (CAC). One study suggests that the absence of CAC associates with no ASCVD events in asymptomatic familial hypercholesterolemia individuals undergoing statin therapy despite elevated residual LDL-cholesterol levels. In contrast, the presence of CAC was independently associated with ASCVD events.

SUMMARY

ASCVD risk is heterogeneous in statin-treated familial hypercholesterolemia individuals. Further studies are necessary to determine how risk stratification, especially with SCA detection, impacts on prescription of proprotein convertase subtilisin kexin type 9 inhibitors within a cost-constrained environment.

Current Status of Familial Hypercholesterolemia in China: A Need for Patient FH Registry Systems

Background: Familial hypercholesterolemia (FH) greatly facilitates the development of cardiovascular disease (CVD). Without timely treatment, the incidence of coronary heart disease (CHD) in patients with FH is 3 to 4 times that in non-FH patients, and the onset of CVD would be advanced by approximately 10 years. There is ample evidence that the diagnosis and adequate treatment of FH are not properly considered for all ethnicities. The monogenic cause of FH includes apolipoprotein B (APOB), low-density lipoprotein receptor (LDLR), and proprotein convertase subtilisin/kexin 9 (PCSK9). There are approximately 2,765,420 to 6,913,550 cases of potential heterozygous FH (HeFH) and 2,205 to 4,609 cases of potential homozygous FH (HoFH) in China. Nevertheless, China lacks clinical diagnostic criteria specific to Chinese patients, such that most FH patients cannot be diagnosed until middle age or after their first cardiovascular event, thus precluding early treatment. Objective: This article explores the gene mutations, diagnosis and treatment of FH patients in China. Following the implementation of the two-child policy, there is a need to establish Chinese FH registry systems and genetic databases and to address the challenges in conducting cascade screening and long-term management. Conclusion: Advocating the establishment of FH registry systems and databases is an important rate-limiting step in improving long-term prognosis in FH patients, so that joint efforts of clinical experts and public communities are required. We recommend a process flow from case identification to entry into the registry system, and the widespread use of the system in clinical applications can provide the best treatment guidance for medical practice.

Atherosclerotic cardiovascular disease risk assessment in familial hypercholesterolemia: does one size fit all?

PURPOSE OF REVIEW

Familial hypercholesterolemia is a frequent genetic disease associated with lifelong elevation of LDL-cholesterol and premature atherosclerotic cardiovascular disease (ASCVD). Statins are the cornerstone of treatment. However, with the introduction of novel LDL-cholesterol-lowering therapies, it is necessary to identify familial hypercholesterolemia patients presenting a significantly high residual ASCVD risk. The aim of this review is to provide an update on the recent literature concerning cardiovascular risk stratification including the role of coronary imaging.

RECENT FINDINGS

Several factors have shown to be independent predictors of ASCVD in familial hypercholesterolemia. These include clinical scores with cardiovascular risk factors, coronary imaging and novel protein biomarkers. However, the recent introduction of the SAFEHEART risk-equation (SAFEHEART-RE) could allow a more accurate ASCVD risk prediction in familial hypercholesterolemia.

SUMMARY

This article highlights the SAFEHEART-RE as a model to predict incident ASCVD in familial hypercholesterolemia. This equation is a simple and widely applicable tool for use in every clinical setting. Furthermore, coronary atherosclerosis assessed by coronary computed-tomographic angiography (coronary-CTA) is independently associated to the cardiovascular risk estimated according to the SAFEHEART-RE. This equation, as well as coronary-CTA and new biomarkers, could increase individual ASCVD risk stratification and could improve the efficiency and the use of new lipid-lowering therapies in familial hypercholesterolemia.

Predictors of Family Enrollment in a Genetic Cascade Screening Program for Familial Hypercholesterolemia

Background

Genetic cascade screening is the most cost-effective method for the identification of individuals with familial hypercholesterolemia (FH), but the best strategies for the enrollment of at-risk individuals in a FH screening program are not fully known.

Objective

The aim of this study is to identify the best predictors of familial enrollment into genetic screening, using features derived from tested probands.

Methods

One hundred and eighty-three index-cases (ICs) with a positive genetic result that had relatives screened from 01/2011 to 07/2015 were included. The response variable was the number of relatives for each enrolled IC. All variables in the study were based on ICs’ derived clinical and socioeconomical features. The effect size of predictor variables were obtained through a general linear model using a negative binomial regression link function. Significance was considered with a p < 0.05.

Results

Mean IC age when enrolling into the program was 50 years old; 78.1% of individuals reported knowledge of relatives with dyslipidemia. Mean baseline LDL-cholesterol level was 316 ± 90 mg/dL. Referral origin through the cascade program website vs. tertiary care, IC LDL-cholesterol and familial history of high LDL-cholesterol levels were independent predictors associated with a higher number of enrolled relatives.

Conclusions

Our data suggest that FH cascade screening programs can predict family enrollment based on IC features. This information may be useful for devising better and more effective screening approaches for at-risk individuals.

Protein changes in non-LDL-lipoproteins in familial hypercholesterolemia: implications in cardiovascular disease manifestation and outcome

PURPOSE OF REVIEW

Familial hypercholesterolemia, represents one of the most extreme clinical entities associated with premature coronary artery disease (CAD). However, clinical manifestation of CAD varies across cohorts and individual patients suggesting the existence of additional non-LDL factors potentially contributing to their cardiovascular burden.

RECENT FINDINGS

Changes in HDL-associated proteins appear as one of the potential additional factors contributing to the cardiovascular risk in familial hypercholesterolemia. Specifically, the content of Apo M-SP1 in HDL3 has been directly associated with cholesterol efflux capacity. In addition, a coordinated decrease in the content of Apo L1 and LCAT in HDL3 has been related to the presence of corneal arcus and to bad prognosis in familial hypercholesterolemia patients after an acute ischemic event. In fact, HDL3 particles of familial hypercholesterolemia patients have diminished antioxidant and anti-inflammatory function.

SUMMARY

The identification of the specific changes in HDL-associated proteins that contribute to the increased cardiovascular risk of familial hypercholesterolemia patients could be useful for the development of novel therapeutic targets. These novel strategies, in combination with current lipid-lowering therapies, may help to reduce the residual risk found in these patients.

The role of registries and genetic databases in familial hypercholesterolemia

PURPOSE OF REVIEW

To review how leveraging familial hypercholesterolemia registries can impact molecular genetic research and precision medicine.

RECENT FINDINGS

Familial hypercholesterolemia is both much more common and more phenotypically heterogeneous than previously thought with some evidence for significant genotype to phenotype correlations. Genetic testing for familial hypercholesterolemia is becoming both more widely available and cheaper, spurring conversations about its clinical utility.

SUMMARY

In most countries, familial hypercholesterolemia is underdiagnosed and diagnosed later in life, often after the onset of coronary heart disease (CHD). Familial hypercholesterolemia is undertreated; low goal attainment and additional modifiable risk factors further increase CHD risk. Familial hypercholesterolemia epitomizes the goal of precision medicine to define a subset of individuals with a high risk of morbidity and mortality through genetic diagnosis to manage and treat the risk accordingly. Genetic cascade screening can be used to identify familial hypercholesterolemia patients at a younger age and start timely treatment to prevent CHD. Familial hypercholesterolemia registries are tools for clinical research and improving healthcare planning and patient care. As genotype and phenotype correlations in familial hypercholesterolemia become increasingly understood, this information will likely play a more important role in diagnosis and treatment especially as the cost of genetic testing continues to decline.

Phenotype vs. genotype in severe familial hypercholesterolemia: what matters most for the clinician?

PURPOSE OF REVIEW

Familial hypercholesterolemia is associated with a high lifetime risk of atherosclerotic cardiovascular disease (ASCVD). However, this risk is variable. This review evaluates recent evidence related to ASCVD risk stratification in familial hypercholesterolemia considering aspects of phenotype and genotype.

RECENT FINDINGS

The heterogeneity in clinical, laboratory characteristics, and in ASCVD risk in both homozygous and heterozygous familial hypercholesterolemia individuals in part can be attributed to the type of molecular defect. In most individuals with LDL cholesterol more than 190 mg/dl, a familial hypercholesterolemia-causing variant is not encountered, however, when present, a variant implicates an even higher ASCVD risk for such individuals. Previous ASCVD events, elevated blood lipoprotein(a), cutaneous markers of cholesterol deposit are among other factors that indicate a higher ASCVD risk in familial hypercholesterolemia individuals underlying a more severe form of the phenotype.

SUMMARY

Both clinical and genetic parameters help identify higher ASCVD risk among severe familial hypercholesterolemia individuals.