A review on the diagnosis, natural history, and treatment of familial hypercholesterolaemia

Non-HDL or LDL cholesterol in heterozygous familial hypercholesterolaemia: findings of the Simon Broome Register

PURPOSE OF REVIEW

The role of non-HDL-C in the identification and management of lipid disorders is not clearly defined, although UK guidelines recommend its wider use in assessing the need for lipid-lowering therapy and as a treatment target.

RECENT FINDINGS

We examined the implications of the use of non-HDL-C as opposed to LDL-C in 253 people with hypercholesterolaemia before treatment and 573 after treatment in whom fasting total serum cholesterol, HDL-C and LDL-C had been recorded and the diagnosis of heterozygous familial hypercholesterolemia (heFH) was investigated by genetic testing. The difference and the limits of agreement between non-HDL-C and LDL-C calculated using the Friedewald formula were assessed in those with and without heFH-causing mutations.

SUMMARY

There were 147 mutation-positive and 106 mutation-negative pretreatment participants and 395 mutation-positive and 178 mutation-negative patients receiving treatment. The difference between non-HDL-C and LDL-C pretreatment in mutation-positive people (mean LDL-C 7.73 mmol/l) was 0.67 mmol/l (95% CI 0.62-0.73) and posttreatment (mean LDL-C 4.71 mmol/l) was 0.62 mmol/l (95% CI 0.59-0.65) with wide limits of agreement of -0.02 to 1.37 and 0.07-1.18 mmol/l, respectively. Among patients with heterozygous familial hypercholesterolaemia, use of estimated LDL-C derived from non-HDL-C in place of calculated LDL-C may result in diagnostic misclassification and difficulty in assessing the true reduction in LDL-C with treatment, because of the wide inter-individual limits of agreement around the mean difference between non-HDL-C and LDL-C.

Genetic Diagnosis of Familial Hypercholesterolemia in Asia

Familial hypercholesterolemia (FH) is a common genetic disease with an incidence of about 1 in 200-500 individuals. Genetic mutations markedly elevate low-density lipoprotein cholesterol and atherosclerotic cardiovascular disease (ASCVD) in FH patients. With advances in clinical diagnosis and genetic testing, more genetic mutations have been detected, including those in low-density lipoprotein receptor (LDLR), apolipoprotein B (APOB), proprotein convertase subtilisin/kexin type 9 (PCSK9), and so on. Globally, most FH patients remain undiagnosed, untreated, or inappropriately treated. Recently, there was a Global Call to Action by the Global Familial Hypercholesterolemia Community to reduce the health burden of FH. Asia, despite being the most populous continent with half of the global population, has low FH detection rates compared to Western countries. Therefore, we aimed to review the current status of FH genetic diagnosis in Asia to understand the gaps in FH diagnosis and management in this region.

The Prevalence and Diagnostic Ratio of Familial Hypercholesterolemia (FH) and Proportion of Acute Coronary Syndrome in Japanese FH Patients in a Healthcare Record Database Study

Background

Familial hypercholesterolemia (FH) is a genetic disorder characterized by high levels of low-density lipoprotein cholesterol (LDL-C). Because of underdiagnosis, acute coronary syndrome (ACS) is often the first clinical manifestation of FH. In Japan, there are few reports on the prevalence and diagnostic ratios of FH and the proportion of ACS among FH patients in clinical settings.

Methods

This retrospective, observational study used anonymized data from electronic healthcare databases between April 2001 and March 2015 of patients who had ≥2 LDL-C measurements recorded after April 2009. The index date was defined as the date of the first LDL-C measurement after April 2009. The primary endpoint was the prevalence of definite or suspected FH; secondary endpoints included the proportion of FH patients hospitalized for ACS, the proportion of patients using lipid-lowering drugs (LLDs), and LDL-C levels.

Results

Of the 187,781 patients screened, 1547 had definite or suspected FH (0.8%) based on data from the entire period; 832 patients with definite (n = 299, 0.16%) or suspected FH (n = 533, 0.28%) before the index date were identified in the main analysis cohort. LLDs were used in 214 definite FH patients (71.6%) and 137 suspected FH patients (25.7%). Among definite or suspected FH patients with ACS (n = 84) and without ACS (n = 748), 32.1% and 30.1% with definite FH and 3.2% and 2.4% with suspected FH had LDL-C levels < 2.6 mmol/L (<100 mg/dL), respectively. Sixty patients (7.2%) were hospitalized due to ACS at the index date.

Conclusions

The prevalence of FH in this Japanese cohort of patients with ≥2 LDL-C measurements at hospitals was 0.8%, which is higher than that currently reported in epidemiological studies (0.2-0.5%). Patients with suspected FH, with or without ACS, had poorly controlled LDL-C levels and were undertreated. The proportion of FH patients who were hospitalized due to ACS was 7.2%.

Analysis of incidence and prevalence of cardiovascular risk factors and evaluation of their control in epidemiological survey in the Czech Republic

OBJECTIVE

The aim of this analysis was to analyze the presence of the most important cardiovascular (CV) risk factors and to discuss patterns of LDL cholesterol management in the population studied.

METHODS

We enrolled 961 males, average age of 42.9 ± 4.7, and 851 females, average age of 51.2 ± 3.6. Data on personal, pharmacological and family history, and laboratory examinations were collected. Cardiovascular (CV) risk was calculated using the Systematic Coronary Risk Evaluation (SCORE) algorithm with modifications according to the guidelines.

RESULTS

The distribution of CV risk in the observed cohort was as follows: 24% of the subjects had low, 51% moderate, 17% high and 8% very high risk. The percentage of patients who reached target values of LDL cholesterol was dramatically lower in the groups with very high (1%) and high (3%) risk than in the groups with moderate (14%) or low risk (59%). Dyslipidemia was newly identified in 20% of both sexes. Arterial hypertension was newly diagnosed in 8% of males and 5% of females, and type 2 diabetes mellitus was newly diagnosed in 3% of both the males and females. Dyslipidemia was present in 39% of males and 41% of females; arterial hypertension in 43% of males and 45% of females, and type 2 diabetes mellitus was diagnosed in 11% of the subjects of both sexes. 49% of males and 31% of females were overweight and 32% of both genders were obese. There were 36% of male smokers and 22% of female smokers. 48% of the participants were pharmacologically treated. Non-pharmacological treatment was recommended to 62% of male and to 65% of female participants. Pharmacological intervention was started in 53% of males and 51% of females. In both gender antihypertensive treatment with angiotensin-converting enzyme (ACE) inhibitors (29% of males and 27% of females) and lipid lowering therapy with a statin (28% of males, 27% of females) were the most commonly initiated treatments. In the subgroup of the 101 patients with LDL cholesterol levels > 5 mmol/L 56% were not treated with a statin. The analysis of relationship between the positive family history of any of the followed CV risks showed significant increases of the risk for arterial hypertension, type 2 diabetes mellitus and dyslipidemia.

CONCLUSION

European guidelines suggest general screening for risk factors, including analysis of lipid profiles in the population of 40-year-old males and 50-year-old or postmenopausal women. Our study documents high prevalence and incidence of CV risk factors together with insufficient control of the risk factors in Czech patients of this age range. This finding suggests that preventive examinations should be undertaken earlier (e.g., in 30-year-old males and 40-year-old women). Exact timing of the preventive check-ups to yield the best cost-benefit ratio needs to be verified.

Detection of familial hypercholesterolaemia: external validation of the FAMCAT clinical case-finding algorithm to identify patients in primary care

BACKGROUND

The vast majority of individuals with familial hypercholesterolaemia in the general population remain unidentified worldwide. Recognising patients most likely to have the condition, to enable targeted specialist assessment and treatment, could prevent major coronary morbidity and mortality. We aimed to evaluate a clinical case-finding algorithm, the familial hypercholesterolaemia case ascertainment tool (FAMCAT), and compare it with currently recommended methods for detection of familial hypercholesterolaemia in primary care.

METHODS

In this external validation study, FAMCAT regression equations were applied to a retrospective cohort of patients aged 16 years or older with cholesterol assessed, who were randomly selected from 1500 primary care practices across the UK contributing to the QResearch database. In the main analysis, we assessed the ability of FAMCAT to detect familial hypercholesterolaemia (ie, its discrimination) and compared it with that of other established clinical case-finding approaches recommended internationally (Simon Broome, Dutch Lipid Clinic Network, Make Early Diagnosis to Prevent Early Deaths [MEDPED] and cholesterol concentrations higher than the 99th percentile of the general population in the UK). We assessed discrimination by area under the receiver operating curve (AUROC; ranging from 0·5, indicating pure chance, to 1, indicating perfect discrimination). Using a probability threshold of more than 1 in 500 (prevalence of familial hypercholesterolaemia), we also assessed sensitivity, specificity, positive predictive values, and negative predictive values in the main analysis.

FINDINGS

A sample of 750 000 patients who registered in 1500 UK primary care practices that contribute anonymised data to the QResearch database between Jan 1, 1999, and Sept 1, 2017, was randomly selected, of which 747 000 patients were assessed. FAMCAT showed a high degree of discrimination (AUROC 0·832, 95% CI 0·820-0·845), which was higher than that of Simon Broome criteria (0·694, 0·681-0·703), Dutch Lipid Clinic Network criteria (0·724, 0·710-0·738), MEDPED criteria (0·624, 0·609-0·638), and screening cholesterol concentrations higher than the 99th percentile (0·581, 0·570-0·591). Using a 1 in 500 probability threshold, FAMCAT achieved a sensitivity of 84% (1028 predicted vs 1219 observed cases) and specificity of 60% (443 949 predicted vs 745 781 observed non-cases), with a corresponding positive predictive value of 0·84% and a negative predictive value of 99·2%.

INTERPRETATION

FAMCAT identifies familial hypercholesterolaemia with greater accuracy than currently recommended approaches and could be considered for clinical case finding of patients with the highest likelihood of having hypercholesterolaemia in primary care.

FUNDING

UK National Institute for Health Research School for Primary Care Research.

Prevalence of Familial Hypercholesterolemia Among the General Population and Patients With Atherosclerotic Cardiovascular Disease

Background:

Contemporary studies suggest that familial hypercholesterolemia (FH) is more frequent than previously reported and increasingly recognized as affecting individuals of all ethnicities and across many regions of the world. Precise estimation of its global prevalence and prevalence across World Health Organization regions is needed to inform policies aiming at early detection and atherosclerotic cardiovascular disease (ASCVD) prevention. The present study aims to provide a comprehensive assessment and more reliable estimation of the prevalence of FH than hitherto possible in the general population (GP) and among patients with ASCVD.

Methods:

We performed a systematic review and meta-analysis including studies reporting on the prevalence of heterozygous FH in the GP or among those with ASCVD. Studies reporting gene founder effects and focused on homozygous FH were excluded. The search was conducted through Medline, Embase, Cochrane, and Global Health, without time or language restrictions. A random-effects model was applied to estimate the overall pooled prevalence of FH in the general and ASCVD populations separately and by World Health Organization regions.

Results:

From 3225 articles, 42 studies from the GP and 20 from populations with ASCVD were eligible, reporting on 7 297 363 individuals/24 636 cases of FH and 48 158 patients/2827 cases of FH, respectively. More than 60% of the studies were from Europe. Use of the Dutch Lipid Clinic Network criteria was the commonest diagnostic method. Within the GP, the overall pooled prevalence of FH was 1:311 (95% CI, 1:250–1:397; similar between children [1:364] and adults [1:303], P =0.60; across World Health Organization regions where data were available, P =0.29; and between population-based and electronic health records–based studies, P =0.82). Studies with ≤10 000 participants reported a higher prevalence (1:200–289) compared with larger cohorts (1:365–407; P <0.001). The pooled prevalence among those with ASCVD was 18-fold higher than in the GP (1:17 [95% CI, 1:12–1:24]), driven mainly by coronary artery disease (1:16; [95% CI, 1:12–1:23]). Between-study heterogeneity was large ( I 2 >95%). Tests assessing bias were nonsignificant ( P >0.3).

Conclusions:

With an overall prevalence of 1:311, FH is among the commonest genetic disorders in the GP, similarly present across different regions of the world, and is more frequent among those with ASCVD. The present results support the advocacy for the institution of public health policies, including screening programs, to identify FH early and to prevent its global burden.

Assessment of medical intern's knowledge, awareness and practice of familial hypercholesterolemia at academic institutes in Jeddah, Saudi Arabia

Background

Familial Hypercholesterolemia (FH) is a serious under-diagnosed disease characterized by raised low-density lipoprotein cholesterol (LDL-C) and premature coronary artery diseases (CAD). The scarcity of FH reported patients in Saudi Arabia indicates lack of FH awareness among physicians.

Objective

The goal of this research was to assess knowledge, awareness, and practice (KAP) about FH disorder among Saudi medical interns and to identify areas that need educational attention.

Methods

This cross-sectional study involved 170 Saudi medical interns (83 males and 87 females) from academic institutes in Jeddah, Saudi Arabia. The interns were asked to fill an online FH-KAP questionnaire. Total score for each separate domain measured by adding correct answers.

Results

Although, knowledge of FH definition (76.5%) and classical lipid profile (52.4%) were reasonable; knowledge on inheritance (43.5%), prevalence (12.4%) and CAD risks (7.1%) were poor. Knowledge score was significantly higher in female than male (7.5 ± 3 vs. 5.3 ± 2.6, P < 0.001). Regarding awareness, 54.1% were familiar with FH disorder, 50.6% with the presence of lipid clinic but only 16.5% were acquainted with guidelines. Furthermore, in the practice domain 82.9% selected statin as first line treatment and 62.9% chose routinely checking the rest of the family, while 15.3% chose ages 13–18 years to screen for hypercholesterolemia in patients with a positive family history of premature CAD.

Conclusion

Substantial defects in FH-KAP among Saudi medical interns were found, emphasizing the importance of professional training. Extensive and constant medical education programs as early as an internship are required to close the gap in CAD prevention.

The evaluation and management of patients with LDL-C ≥ 190 ​mg/dL in a large health care system

Objectives

Patients with severe hyperlipidemia (low-density lipoprotein-cholesterol (LDL-C) ≥190 ​mg/dL) have a significantly increased risk of cardiovascular disease (CVD) and are more likely to have familial hypercholesterolemia (FH). We sought to determine how often health care providers recognize the implications of and adjust therapy for an LDL-C ≥190 ​mg/dL.

Methods

We conducted a retrospective review of patients with an LDL-C measurement in the medical record of a large health care system between November 2015 and June 2016. Patients were restricted to those with LDL-C ≥190 ​mg/dL and without secondary causes of dyslipidemia, with sensitivity analyses for those with LDL-C ≥220 ​mg/dL.

Results

Of 27,963 patients, 227 had LDL-C ≥190 ​mg/dL. Only 21% were on a statin at the time of LDL-C measurement. More than 90% had a follow-up clinic visit, but 41% had no change in treatment. FH was only included in the differential for 14%. The presence/absence of a family history of dyslipidemia, myocardial infarction, and premature CVD were documented in 26%, 29%, and 31%. Only 20.7% and 22.1% had documentation of the presence or absence of tendinous xanthomas or corneal arcus, respectively. Among those without prior specialist care (cardiologist or endocrinologist), only 13% were referred. These measures were only slightly better for those with LDL-C ≥220 ​mg/dL.

Conclusion

In a large health care system, the possibility of FH was rarely acknowledged in those with residual LDL-C ≥190 ​mg/dL, few were referred to specialists, and therapeutic adjustments were suboptimal. Additional efforts are required to understand barriers to improving the evaluation and management of patients with LDL-C ≥190 ​mg/dL.

Probucol Trial for Secondary Prevention of Atherosclerotic Events in Patients with Coronary Heart Disease (PROSPECTIVE)

AIMS

Although intensive statin therapy reduced cardiovascular risks, cardiovascular events have not been completely prevented. Probucol is a potent antioxidant and reduces tendon xanthomas in familial hypercholesterolemia patients despite reduction of high-density lipoprotein (HDL)-cholesterol (HDL-C). We investigated whether probucol can reduce cardiovascular events on top of conventional lipid-lowering therapy in patients with coronary heart disease (CHD).

METHODS

PROSPECTIVE is a multicenter, randomized, prospective study that recruited 876 Japanese patients with CHD and dyslipidemia with a low-density lipoprotein (LDL)-cholesterol (LDL-C) level of ≥ 140 mg/dL without medication or those treated with lipid-lowering drugs. Lipid-lowering agents were administered during the study period in the control group (n=438), and probucol 500 mg/day was added to lipid-lowering therapy in the probucol group (n=438). Patients were randomly assigned to two treatment groups by adjusting the LDL-C level and presence of diabetes and hypertension and followed up for more than 3 years. The primary end point was a composite of cerebrovascular and cardiovascular events (cardiovascular disease death including sudden death, nonfatal myocardial infarction, nonfatal stroke, hospitalization for unstable angina, hospitalization for heart failure, or coronary revascularization). The secondary end point was carotid intima-media thickness in a subset of patients.

RESULTS

The incidence of the primary end point showed a trend to be lower in the probucol group compared with that in the control group despite reduced HDL-C without serious adverse events. Anti-atherogenic effects of probucol may be attributed to its potent antioxidative function and enhancement of reverse cholesterol transport.

CONCLUSION

Since there was no statistical significance between the probucol and control groups despite a marked reduction of HDL-C, further studies on the clinical outcomes of probucol on top of conventional therapy may be necessary in the future (UMIN000003307).

Effects of a low-fat dietary regimen enriched with soy in children affected with heterozygous familial hypercholesterolemia

INTRODUCTION

Familial hypercholesterolemia (FH) is an inheritable, autosomal dominant disorder leading to pathologically increased levels of low-density-lipoprotein cholesterol (LDL-C). Dietary treatment remains an important tool in the management of affected children even after the decision for the initiation of pharmacotherapy is made. However, little evidence is available regarding the optimal dietary regimen for the treatment of children affected with FH.

METHODS

We present results from a randomized controlled trial in paediatric patients affected with heterozygous FH, assessing the effect of a soy-enriched fat modified diet (soy group) compared to fat modified diet (Control group) alone on LDL-C over a period of 13 weeks. Furthermore, we monitored isoflavone levels in plasma and urine as markers of adherence to the dietary treatments.

RESULTS

LDL-C decrease was statistically significantly greater in the soy group compared to the control group at week 7 (Control group 176.3 ± 27.8 mg/dl, soy group 154.7 ± 29.2 mg/dl, p = 0.038), and showed a trend towards significant at week 13 (Control group 179.9 ± 41.8 mg/dl, soy group 155.0 ± 30.2 mg/dl, p = 0.089). Relative LDL-C decrease correlated significantly with the following plasma isoflavone concentrations measured in week 7: daidzein (p < 0.004, r = 0.576) and genistein (p < 0.017, r = 0.490).

CONCLUSIONS

We provide evidence from a small randomized-controlled trial for the effectiveness and safety of a dietary treatment with soy in paediatric patients affected with heterozygous FH. The decrease in LDL-C was highly correlated with isoflavone levels, further highlighting a direct effect of soy ingestion. This study was registered under ClinicalTrials.gov Identifier No. NCT03563547.

Reference values for lipid profile in Iranian children and adolescents: the CASPIAN-V study

BACKGROUND

We aimed to develop the age- and sex-specific reference values for lipid profile of Iranian pediatric population.

METHODS

Fasting lipid profiles of 3843 participants, aged 7 to 18 years, were extracted from a surveillance survey on Iranian children and adolescents living in 30 provinces across the country.

RESULTS

The mean (SD) age of participants was 12.3(3.1) years, and 52.3% of them were boys. Significant differences were observed between genders comparing the levels of triglyceride (TG) (P = 0.04), total cholesterol (TC) (P = 0.02), low-density lipoprotein- cholesterol (LDL-C) (P = 0.01), and non-high-density lipoprotein cholesterol (non-HDL-C) (P = 0.03). In both genders, TG levels increased with age in the 75th and higher percentiles. Among boys, TC showed a decreasing trend at all percentiles and all age groups. In girls, TC levels increased with age at all percentiles except for the 75th and 90th percentiles. Among boys, the levels of LDL-C and HDL-C decreased with age in all percentiles. However, LDL-C and HDL-C concentrations increased up to the 50th percentile in girls and then decreased with age. The non-HDL-C level decreased in the 50th and higher percentiles among boys and in the 90th and 95th percentiles among girls. The TG/HDL-C ratio increased with age at all percentiles in boys. In girls, TG/HDL-C ratio increased with age in the 50th and higher percentiles.

CONCLUSIONS

Based on the observed differences, it seems necessary to determine age- and sex-specific cut-off values for lipid parameters of children and adolescents in different populations.

Genetic analysis of familial hypercholesterolemia in Asian Indians: A single-center study

BACKGROUND

Familial hypercholesterolemia (FH), an autosomal codominant disorder characterized by very high low-density lipoprotein cholesterol, is strongly associated with premature coronary artery disease.

OBJECTIVES

Molecular landscape of FH in Asian Indians is not well studied, although this ethnic group comprises a large proportion of the world population. Knowledge of mutations in these groups is useful for identifying persons affected with FH, saving their lives, and cascade screening in their relatives.

METHODS

Potential cases of FH (n = 100) were identified by criteria adapted for the Indian population from Dutch Lipid Clinic Network criteria. Pathogenic variants were analyzed in LDLR, APOB 100 (exons 26 and 29), PCSK9, and APOE genes using Sanger sequencing and multiplex ligation-dependent probe amplification technique. Cases in whom there were no pathogenic variants were tested by next-generation sequencing using a targeted panel of genes.

RESULTS

Thirty-eight pathogenic variants were identified in 47 of 100 unrelated probands. Of these variants, 33 were identified in LDLR, 3 in APOB, and 2 in PCSK9 genes. Ten pathogenic variants were novel. Mutations were detected in 91.4% of those subjects classified as definite, 40% as probable, and in 18.8% as possible FH cases based on modified Dutch Lipid Clinic Network criteria. A likely founder mutation in intron 10 (c.1587-1G>A) of LDLR gene was observed in 6 North Indian families. The conventional pathogenic variants in APOB and PCSK9 genes and those previously reported in LDLR gene among Asian Indians were not detected in this cohort.

CONCLUSION

This study demonstrates genetic heterogeneity of FH in India. The variants observed were different from those described in Western populations. Next-generation sequencing technology helped identify new mutations in APOB gene, suggesting that in less-studied populations, it is better to sequence the whole gene rather than test for specific mutations.

Cardiovascular Disease Prevention: The Earlier the Better? A Review of Plant Sterol Metabolism and Implications of Childhood Supplementation

Atherosclerosis is the underlying cause of major cardiovascular events. The development of atherosclerotic plaques begins early in life, indicating that dietary interventions in childhood might be more effective at preventing cardiovascular disease (CVD) than treating established CVD in adulthood. Although plant sterols are considered safe and consistently effective in lowering plasma cholesterol, the health effects of early-life supplementation are unclear. Studies suggest there is an age-dependent effect on plant sterol metabolism: at a younger age, plant sterol absorption might be increased, while esterification and elimination might be decreased. Worryingly, the introduction of low-cholesterol diets in childhood may unintentionally favor a higher intake of plant sterols. Although CVD prevention should start as early as possible, more studies are needed to better elucidate the long-term effects of plant sterol accumulation and its implication on child development.

Familial Hypercholesterolaemia in 2020: A Leading Tier 1 Genomic Application

Familial hypercholesterolaemia (FH) is caused by a major genetic defect in the low-density lipoprotein (LDL) clearance pathway. Characterised by LDL-cholesterol elevation from birth, FH confers a significant risk for premature coronary artery disease (CAD) if overlooked and untreated. With risk exposure beginning at birth, early detection and intervention is crucial for the prevention of CAD. Lowering LDL-cholesterol with lifestyle and statin therapy can reduce the risk of CAD. However, most individuals with FH will not reach guideline recommended LDL-cholesterol targets. FH has an estimated prevalence of approximately 1:250 in the community. Multiple strategies are required for screening, diagnosing and treating FH. Recent publications on FH provide new data for developing models of care, including new therapies. This review provides an overview of FH and outlines some recent advances in the care of FH for the prevention of CAD in affected families. The future care of FH in Australia should be developed within the context of the National Health Genomics Policy Framework.

Endoplasmic reticulum quality control in lipoprotein metabolism

Lipids play a critical role in energy metabolism, and a suite of proteins is required to deliver lipids to tissues. Several of these proteins require an intricate endoplasmic reticulum (ER) quality control (QC) system and unique secondary chaperones for folding. Key examples include apolipoprotein B (apoB), which is the primary scaffold for many lipoproteins, dimeric lipases, which hydrolyze triglycerides from circulating lipoproteins, and the low-density lipoprotein receptor (LDLR), which clears cholesterol-rich lipoproteins from the circulation. ApoB requires specialized proteins for lipidation, dimeric lipases lipoprotein lipase (LPL) and hepatic lipase (HL) require a transmembrane maturation factor for secretion, and the LDLR requires several specialized, domain-specific chaperones. Deleterious mutations in these proteins or their chaperones may result in dyslipidemias, which are detrimental to human health. Here, we review the ER quality control systems that ensure secretion of apoB, LPL, HL, and LDLR with a focus on the specialized chaperones required by each protein.

Genes Potentially Associated with Familial Hypercholesterolemia

This review addresses the contribution of some genes to the phenotype of familial hypercholesterolemia. At present, it is known that the pathogenesis of this disease involves not only a pathological variant of low-density lipoprotein receptor and its ligands (apolipoprotein B, proprotein convertase subtilisin/kexin type 9 or low-density lipoprotein receptor adaptor protein 1), but also lipids, including sphingolipids, fatty acids, and sterols. The genetic cause of familial hypercholesterolemia is unknown in 20%–40% of the cases. The genes STAP1 (signal transducing adaptor family member 1), CYP7A1 (cytochrome P450 family 7 subfamily A member 1), LIPA (lipase A, lysosomal acid type), ABCG5 (ATP binding cassette subfamily G member 5), ABCG8 (ATP binding cassette subfamily G member 8), and PNPLA5 (patatin like phospholipase domain containing 5), which can cause aberrations of lipid metabolism, are being evaluated as new targets for the diagnosis and personalized management of familial hypercholesterolemia.

Comparison of the characteristics at diagnosis and treatment of children with heterozygous familial hypercholesterolaemia (FH) from eight European countries

Background and aims

For children with heterozygous familial hypercholesterolaemia (HeFH), European guidelines recommend consideration of statin therapy by age 8–10 years for those with a low density lipoprotein cholesterol (LDL-C) >3.5 mmol/l, and dietary and lifestyle advice. Here we compare the characteristics and lipid levels in HeFH children from Norway, UK, Netherlands, Belgium, Czech Republic, Austria, Portugal and Greece.

Methods

Fully-anonymized data were analysed at the London centre. Differences in registration and on treatment characteristics were compared by standard statistical tests.

Results

Data was obtained from 3064 children. The median age at diagnosis differed significantly between countries (range 3–11 years) reflecting differences in diagnostic strategies. Mean (SD) LDL-C at diagnosis was 5.70 (±1.4) mmol/l, with 88% having LDL-C>4.0 mmol/l. The proportion of children older than 10 years at follow-up who were receiving statins varied significantly (99% in Greece, 56% in UK), as did the proportion taking Ezetimibe (0% in UK, 78% in Greece). Overall, treatment reduced LDL-C by between 28 and 57%, however, in those >10 years, 23% of on-treatment children still had LDL-C>3.5 mmol/l and 66% of those not on a statin had LDL-C>3.5 mmol/l.

Conclusions

The age of HeFH diagnosis in children varies significantly across 8 countries, as does the proportion of those >10 years being treated with statin and/or ezetimibe. Approximately a quarter of the treated children and almost three quarters of the untreated children older than 10 years still have LDL-C concentrations over 3.5 mmol/l. These data suggest that many children with FH are not receiving the full potential benefit of early identification and appropriate lipid-lowering treatment according to recommendations.

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The age of HeFH diagnosis varies significantly between 8 European countries.

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The proportion of HeFH children being treated varies across 8 European countries.

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A quarter of FH children on statins have LDL-C above the target (>3.5 mmol/L).

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Many FH children are not getting the full benefit of early diagnosis and treatment.

Clinical Evaluation Of Evolocumab For The Treatment Of Homozygous Familial Hypercholesterolemia In Chinese Patients

Evolocumab, which can lower low-density lipoprotein (LDL) cholesterol levels by approximately 60% and prevent cardiovascular events in patients with cardiovascular disease, is a monoclonal antibody that inhibits proprotein convertase subtilisin/kexin type 9 (PCSK9). Some studies have investigated its efficacy and safety in the treatment of the homozygous form of familial hypercholesterolemia (HoFH), and others have focused on its efficacy and safety in Asians with high cardiovascular risk. Although no direct evolocumab clinical trials have been conducted in Chinese HoFH patients, its efficacy and safety in the Chinese population should be similar to those in other ethnic groups.

The curative treatment of familial hypercholesterolemia: Liver transplantation

BACKGROUND

Familial hypercholesterolemia (FH) is an autosomal dominant genetic disorder characterized by premature mortal cardiovascular complications. Liver transplantation (LT) is the only curative treatment option. In this study, the long-term clinical follow-up data of 8 patients who underwent LT with a diagnosis of FH in our center are presented.

MATERIALS AND METHODS

A total of 638 LT were performed between December 1985 and June 2019 at Baskent University, of which 8 patients underwent LT with a diagnosis of FH and were evaluated retrospectively.

RESULTS

Of the 8 patients, 4 underwent deceased donor and 4 living donor transplantation. Five patients had preoperative cardiovascular disease and consequent interventional operations. There was significant reduction in postoperative LDL-C and TC levels starting from the first week, and stabilizing at the first month and first year. The median survival time of patients was 5 years (2-12 years). All patients are still alive. None of the complications of patients with preoperative cardiovascular complications had progressed.

CONCLUSION

Liver transplantation is the preferred curative treatment for the pathophysiology of FH. In our study, LDL-C levels were brought under control with LT performed on patients with FH. Median 5-year follow-up of patients showed that the progression of cardiac complications was abated.

Identification of a novel LDLR disease-causing variant using capture-based next-generation sequencing screening of familial hypercholesterolemia patients in Taiwan

BACKGROUND AND AIMS

Familial hypercholesterolemia (FH) is an autosomal dominant disorder with paramount health impacts. However, less than 1% FH patients in Taiwan were formally diagnosed, partly due to the lack of reliable cost-effective genetic testing. We aimed at using a next-generation sequencing (NGS) platform as the clinical genetic testing method for FH.

METHODS

We designed probes to capture the whole LDLR gene and all coding sequences of APOB and PCSK9, and then sequenced with Illumina MiSeq platform (2 × 300 bps). The entire pipeline was tested on 13 DNA samples with known causative variants (including 3 large duplications and 2 large deletions). Then we enrolled a new cohort of 28 unrelated FH patients with Dutch Lipid Clinic Network score ≥5. Relatives were included in the cascade screening.

RESULTS

From the 13 DNA samples, we correctly identify all the variants, including big duplications and deletions. From the new cohort, we identified the causative variants in 21 of the 28 unrelated probands; five of them carrying a novel splice site variant c.1186+2T>G in LDLR. Among the family members, the concentration of LDL cholesterol was 7.82 ± 2.13 mmol/l in LDLR c.1186+2T>G carrier group (n = 26), and was significantly higher than 3.18 ± 1.36 mmol/l in the non-carrier group (n = 25).

CONCLUSIONS

This is the first capture-based NGS testing for FH to cover the whole LDLR genomic region, and therefore making reliable structural variation detection. This panel can comprehensively detect disease-causing variants in LDLR, APOB, and PCSK9 for FH patients.

Practical definitions of severe versus familial hypercholesterolaemia and hypertriglyceridaemia for adult clinical practice

Diagnostic scoring systems for familial hypercholesterolaemia and familial chylomicronaemia syndrome often cannot differentiate between adults who have extreme dyslipidaemia based on a simple monogenic cause versus people with a more complex cause involving polygenic factors and an environmental component. This more complex group of patients carries a substantial risk of atherosclerotic cardiovascular disease in the case of marked hypercholesterolaemia and pancreatitis in the case of marked hypertriglyceridaemia. Complications are mainly a function of the degree of disturbance in lipid metabolism resulting in elevated lipid levels, so the added value of knowing the precise genetic cause in clinical decision making is unclear and does not lead to clinically meaningful benefit. We propose that for severe elevations of plasma low density lipoprotein cholesterol or triglyceride, the primary factor driving intervention should be the biochemical perturbation rather than the clinical risk score. This underscores the importance of expanding the definition of severe dyslipidaemias and to not rely solely on clinical scoring systems to identify individuals who would benefit from appropriate treatment approaches. We advocate for the use of simple, practical, clinical, and largely biochemically based definitions for severe hypercholesterolaemia (eg, LDL cholesterol >5 mmol/L) and severe hypertriglyceridaemia (triglyceride >10 mmol/L), which complement current definitions of familial hypercholesterolaemia and familial chylomicronaemia syndrome. Irrespective of the precise genetic cause, individuals diagnosed with severe hypercholesterolaemia and severe hypertriglyceridaemia require intensive therapy, including special consideration for new effective but more expensive therapies.

Mutational analysis of the LDLR gene in a cohort of Colombian families with familial hypercholesterolemia

BACKGROUND AND AIMS

Familial hypercholesterolemia (FH) is characterized by elevated serum cholesterol levels due to high low-density lipoprotein (LDL) cholesterol levels. FH is an autosomal dominant genetic disorder and one of the most common dominant hereditary diseases in the world. However, the frequency of mutations in Colombia is unknown. The purpose of this preliminary study was to identify mutations in the LDL receptor (LDLR) gene in a Colombian population with FH.

METHODS

The study included 24 families with clinical diagnosis of sure/probable FH. The 18 exons of the LDLR were sequenced by Sanger method.

RESULTS

Among 18 variants identified, 3 were known pathogenic mutations and were identified in nine individuals in five unrelated families. Five affected individuals were heterozygous for one mutation each. They were the p.W4X in two, the p.D139G in two and the p.G396D in one. Two affected individuals were homozygous for p.G396D. The variant c.1187-1G > T, which has uncertain significance in FH pathogenesis, was present in all the individuals with the p.D139G mutation.

CONCLUSIONS

In total, 18 variants were identified, of which 14 correspond to known nonpathogenic variants. Three pathogenic variants were identified in the LDLR. No pathological mutations were identified in the LDLR in 79% of the study population.

Clinical utility of the polygenic LDL-C SNP score in familial hypercholesterolemia

Mutations in any of three genes (LDLR, APOB and PCSK9) are known to cause autosomal dominant FH, but a mutation can be found in only ∼40% of patients with a clinical diagnosis of FH. In the remainder, a polygenic aetiology may be the cause of the phenotype, due to the co-inheritance of common LDL-C raising variants. In 2013, we reported the development of a 12-SNP LDL-C "SNP-Score" based on common variants identified as LDL-C raising from genome wide association consortium studies, and have confirmed the validity of this score in samples of no-mutation FH adults and children from more than six countries with European-Caucasian populations. In more than 80% of those with a clinical diagnosis of FH but with no detectable mutation in LDLR/APOB/PCSK9, the polygenic explanation is the most likely for their hypercholesterolaemia. Those with a low score (in the bottom two deciles) may have a mutation in a novel gene, and further research including whole exome or whole genome sequencing is warranted. Only in families where the index case has a monogenic cause should cascade testing be carried out, using DNA tests for an unambiguous identification of affected relatives. The clinical utility of the polygenic explanation is that it supports a more conservative (less aggressive) treatment care pathway for those with no mutation. The ability to distinguish those with a clinical diagnosis of FH who have a monogenic or a polygenic cause of their hypercholesterolaemia is a paradigm example of the use of genomic information to inform Precision Medicine using lipid lowering agents with different efficacy and costs.

Knowledge, awareness and practice regarding familial hypercholesterolaemia among primary care physicians in Malaysia: The importance of professional training

BACKGROUND AND AIMS

This study aimed to determine knowledge, awareness and practice (KAP) regarding familial hypercholesterolaemia (FH) among Malaysian primary care physicians (PCP), and to compare KAP between PCP with postgraduate qualification (PCP-PG-Qual) and PCP without PG qualification (PCP-noPG-Qual).

METHODS

This was a cross-sectional study involving PCP with ≥1-year working experience in Malaysian primary care settings. An adapted and validated 25-item FH-KAP questionnaire was disseminated during primary care courses. Total score for each domain was calculated by summing-up the correct responses, converted into percentage scores. Normality distribution was examined and comparisons of mean/median percentage scores were made between the two groups of PCP.

RESULTS

A total of 372 PCP completed the questionnaire. Regarding knowledge, 77.7% correctly defined FH. However, only 8.3% correctly identified coronary artery disease risk in untreated FH. The mean percentage knowledge score was significantly higher in PCP-PG-Qual compared to PCP-noPG-Qual (48.9, SD ± 13.92 vs. 35.2, SD ± 14.13), t(370) = 8.66, p < 0.001. Regarding awareness, 39% were aware of the NICE FH guideline and only 27.2% were aware of FH diagnostic criteria. The median percentage awareness score was significantly higher in PCP-PG-Qual compared to PCP-noPG-Qual (15.4, IqR ± 23.08 vs. 7.7, IqR ± 11.54), p = 0.013. Regarding practice, only 19.1% stratified FH patients as high risk irrespective of other risk factors. The mean percentage practice score was significantly higher in PCP-PG-Qual compared to PCP-noPG-Qual (52.4, SD ± 12.92 vs. 42.7, SD ± 16.63), t(370) = 9.65, p < 0.001.

CONCLUSIONS

Substantial gaps in FH-KAP among Malaysian PCP were identified, with PCP-PG-Qual having better knowledge, awareness and practice than PCP-noPG-Qual, emphasising the importance of professional training and certification.

Identifying Perceptions and Preferences of the General Public Concerning Universal Screening of Children for Familial Hypercholesterolaemia

BACKGROUND/AIMS

Familial hypercholesterolaemia (FH) is a common genetic disorder that, if untreated, predisposes individuals to premature coronary heart disease. As most individuals with FH remain undiagnosed, new approaches to detection are needed and should be considered a priority in public health genomics. Universal screening of children for FH has been proposed, and this study explores public perspectives on the acceptability of this approach.

METHODS

A one-day deliberative public forum was held in Perth, WA, Australia. Thirty randomly selected individuals were recruited, with self-reported sociodemographic characteristics used to obtain discursive representation. Participants were presented with information from a variety of perspectives and asked to discuss the information provided to identify points of consensus and disagreement. The data collected were analysed using thematic analysis.

RESULTS

Of the 17 participants at the forum, 16 deemed universal screening of children for FH to be acceptable. Fifteen of these 16 believed this was best performed at the time of an immunisation. Participants proposed a number of conditions that should be met to reduce the likelihood of unintended harm resulting from the screening process.

DISCUSSION/CONCLUSION

The outcomes of the forum suggest that establishing a universal screening programme for FH in childhood is acceptable to the general public in WA.

Characteristics of Children Referred to a Lipid Clinic Before and After the Universal Screening Guidelines

In 2011, universal lipid screening was recommended for children aged 9 to 11 years; the impact of this recommendation on the lipid clinic setting is unknown. We examined the rate of primary and secondary dyslipidemia diagnoses in a lipid clinic before (2010-2011) and after (2012-2015) the guideline recommendation. We conducted a retrospective study of new clinic patients aged 0 to 20 years seen between April 2010 and April 2015. Chi-square testing was applied. The 345 subjects were 58% males; 48% ≥13 years; 56% Hispanic; and 59% obese. There was no difference in the rate of dyslipidemia diagnoses between periods (before: primary 23%, secondary 73%, no dyslipidemia 4% vs after: 22%, 72%, 6%, respectively; P = .616). There was no significant difference between periods in subject demographics for the total sample, but among those with primary dyslipidemia, pre- to post-guideline percentage of subjects with public insurance decreased (71% to 39%; P = .006). Additional strategies to increase identification of children with dyslipidemia are needed.

High prevalence of genetic determined familial hypercholesterolemia in premature coronary artery disease

Background: Premature coronary artery disease (CAD) is a major cause of mortality and morbidity. Increased low-density lipoprotein-cholesterol (LDL-C) level is a major risk factor for CAD and thus the main target for its prevention. Familial Hypercholesterolemia (FH) is a genetic inherited disorder characterized by high LDL-C, and subsequent premature CAD development. Early drug treatment with lipid-lowering medications in FH prevents cardiovascular disease onset. The FH prevalence in the Northern European general population is 0.3%, and it is estimated that it explains 20% of premature CAD cases in individuals with familial clustering. Despite the wide number of papers showing the prevalence of clinical FH in cardiovascular disease, the prevalence of genetic FH in individuals with premature CAD is not yet well known. Here, we examined the prevalence of genetically determined FH in individuals with premature CAD. Patients and methods: 66 patients who underwent coronary angiography with suspected premature acute coronary syndrome (age <50 years for men and <55 years for women) underwent genetic screening to identify FH-causing mutations. All patients underwent physical and clinical examinations. Information about family and personal history, drug therapy and habits were also collected. Results: We found FH-causative mutations in 3/66 (4.5%) screened individuals with premature CAD. When considering individuals with confirmed CAD after coronary angiography, the FH mutation prevalence was 6.1% (3/49). After excluding individuals with classical risk factors for CAD other than hypercholesterolemia, the FH mutation prevalence raised to 15.8% (3/19). Conclusion: In conclusion, we found that individuals with premature CAD have a more than 15-fold increased prevalence of FH mutations compared to the general population.

Vitamin B3 impairs reverse cholesterol transport in Apolipoprotein E-deficient mice

INTRODUCTION

High Density Lipoproteins (HDL) are dysfunctional in hypercholesterolemia patients. The hypothesis was tested that nicotinamide (NAM) administration will influence HDL metabolism and reverse cholesterol transport from macrophages to the liver and feces in vivo (m-RCT) in a murine model of hypercholesterolemia.

METHODS

Apolipoprotein E-deficient (KOE) mice were challenged with a high-fat diet for 4 weeks. The effect of different doses of NAM on cholesterol metabolism, and the ability of HDL to promote m-RCT was assessed.

RESULTS

The administration of NAM to KOE mice produced an increase (∼1.5-fold; P<0.05) in the plasma levels of cholesterol, which was mainly accounted for by the non-HDL fraction. NAM produced a [³H]-cholesterol plasma accumulation (∼1.5-fold) in the m-RCT setting. As revealed by kinetic analysis, the latter was mainly explained by an impaired clearance of circulating non-HDL (∼0.8-fold). The relative content of [³H]-tracer was lowered in the livers (∼0.6-fold) and feces (>0.5-fold) of NAM-treated mice. This finding was accompanied by a significant (or trend close to significance) up-regulation of the relative gene expression of Abcg5 and Abcg8 in the liver (Abcg5: 2.9-fold; P<0.05; Abcg8: 2.4-fold; P=0.06) and small intestine (Abcg5: 2.1-fold; P=0.15; Abcg8: 1.9-fold; P<0.05) of high-dose, NAM-treated mice.

CONCLUSION

The data from this study show that the administration of NAM to KOE mice impaired m-RCT in vivo. This finding was partly due to a defective hepatic clearance of plasma non-HDL.

The tertiary hospital laboratory; a novel avenue of opportunistic screening of familial hypercholesterolemia

Background

Familial hypercholesterolemia (FH) is a common monogenic hereditary lipid disorder characterised by increased serum low-density lipoprotein cholesterol (LDL-cholesterol) concentrations and high risk of premature atherosclerotic cardiovascular disease. The prevalence of FH identified in a tertiary hospital laboratory was investigated by performing an opportunistic screen for index cases.

Methods

The prevalence of likely FH based on LDL-cholesterol thresholds >4.9 mmol/L as employed by the Dutch Lipid Clinic Network Criteria (DLCNC) score was evaluated retrospectively in a single tertiary hospital laboratory over a six-month period (July to December 2016).

Results

4943 lipid profiles screened, 106 patients (mean age 53.2 ± 12.9 and 41% male) had LDL-cholesterol of >4.9 mmol/L after exclusion of 5 patients (0.1%) with secondary causes. Possible (n = 90) and probable/definite (n = 16) FH according to DLCNC score was seen in 1.8% and 0.4% of the overall screened population, respectively.

Conclusions

Point prevalence of screening for FH in patients undergoing lipid profile testing in a tertiary hospital laboratory was comparable with prevalence of FH in general population (based on 1 in 200-250). This supports the benefit of establishing an efficient "alert system" in conjunction with a trigger "reflex testing" to facilitate further formal FH scoring and exclusion of possible secondary causes of hyperlipidemia in potential index FH.

Polygenic Hypercholesterolemia and Cardiovascular Disease Risk

Purpose of the Review

Identification of loci and common single-nucleotide polymorphisms (SNPs) that have modest effects on plasma lipids have been used to confirm or refute the causal role of lipid traits in the development of coronary heart disease (CHD), and as tools to identify individuals with polygenic hypercholesterolemia.

Recent Findings

Several groups have reported on the use of SNP scores in distinguishing individuals with a clinical diagnosis of familial hypercholesterolemia (FH) with a monogenic or polygenic etiology. We review evidence that those with monogenic FH have worse prognosis and discuss the possible mechanisms for this and their management.

Summary

Individuals with a clinical phenotype of FH and a monogenic cause are at greater risk of CHD than those where no causative mutation can be found. The patients with polygenic hypercholesterolemia would not require elaborate cascade screening or secondary care input for their management.

Clinical Management of High and Very High Risk Patients with Hyperlipidaemia in Central and Eastern Europe: An Observational Study

INTRODUCTION

A retrospective/prospective observational study was conducted to explore the current management of hyperlipidaemia in high-risk (HR) and very high risk (VHR) patients in central/eastern Europe and Israel.

METHODS

The study enrolled adult patients who were receiving lipid-lowering therapy and attending a specialist (cardiologist/diabetologist/lipidologist) or internist for a routine visit at 57 sites (including academic/specialist/internal medicine centres) across Bulgaria, Croatia, Czech Republic, Israel, Poland, Romania and Slovakia. Data were collected from medical records, for the 12 months before enrolment, with/without ≤ 6 months' additional prospective follow-up.

RESULTS

A total of 1244 patients, mean (SD) age 63.3 (11.3) years were included (307 with familial hypercholesterolaemia (FH), 943 secondary prevention patients). Almost all patients (98.1%) were receiving statins (76.7% monotherapy/21.4% combined therapy), with 53.1% receiving high-intensity statin therapy: 127 patients (10.2%) had adverse events attributed to statin intolerance. Mean (SD) low density lipoprotein cholesterol (LDL-C) levels were 3.3 (1.7) mmol/L at the first, and 2.7 (1.3) mmol/L at the last, visit of the retrospective phase of observation, with little change during the prospective phase. Less than one-quarter (23.8%; 95% CI 17.29-31.45%) of HR patients and less than half (42.0%; 39.05-44.98%) of VHR patients achieved their risk-based LDL-C targets of < 2.5 and < 1.8 mmol/L, respectively. Less than 15% of FH patients reached these targets (10.9% (5.6-18.7%) of HR and 12.1% (8.0-17.4%) of VHR patients). The revised 2016 ESC/EAS target for HR patients (2.6 mmol/L) was met by 28.5% (21.44-36.38%) of HR patients overall. Almost one-half of patients (42.1%) experienced one or more cardiovascular events during observation.

CONCLUSION

Our findings confirm that, despite widespread statin use, a substantial proportion of patients treated for hyperlipidaemia in central/eastern Europe and Israel, particularly those with FH, do not reach recommended LDL-C targets, thus remaining at risk of cardiovascular events.

FUNDING

Amgen (Europe) GmbH.

Improving the detection of familial hypercholesterolaemia

Familial hypercholesterolaemia (FH) is a dominantly inherited disorder of low-density lipoprotein (LDL) catabolism, which if untreated causes lifelong elevated LDL-cholesterol (LDL-c), accelerated atherosclerosis and premature cardiovascular disease. Recent evidence suggests the prevalence of heterozygous FH is ∼1:220, making FH the most common autosomal dominant condition. Lowering LDL-c with statin and lifestyle therapy reduces the risk of cardiovascular events. Furthermore, proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors significantly lower LDL-c in addition to statin therapy, and early outcome data suggest improved vascular outcomes with these agents in FH patients in addition to statins. However, the vast majority of people with FH still remain undiagnosed. The onus is on clinicians to identify kindreds with FH, as PCSK9 inhibitors, although expensive, are funded for patients with FH in Australia. Multiple strategies for detecting FH have been proposed. The detection of index cases can be achieved through applying electronic screening tools to general practice databases, universal screening of children during immunisation, and targeted screening of patients with premature cardiovascular disease. Advances in genomic technology have decreased costs of genetic testing, improved the understanding of the pathogenesis of FH and facilitated cascade screening. However, awareness of FH amongst clinicians and the general public still requires optimisation. This review outlines recent advances in FH detection, including emerging strategies and challenges for the next decade.

Grayscale ultrasonic and shear wave elastographic characteristics of the Achilles' tendon in patients with familial hypercholesterolemia: A pilot study

OBJECTIVE

To investigate the feasibility of grayscale ultrasound and quantitative shear wave elastography (SWE) for assessing the image features and stiffness of the Achilles tendon in patients with familial hypercholesterolemia (FH) compared with healthy controls.

METHODS

A total of 38 Achilles tendons from healthy control participants and 94 from patients with FH were examined with grayscale ultrasound and SWE. Each Achilles tendon examination was performed on 3 different segments (proximal, middle, and distal). The thickness, grayscale image features and elasticity modulus of each segment was measured on longitudinal views.

RESULTS

In Achilles tendons of healthy control participants, the thicknesses of the proximal, middle, and distal segments were (4.46 ± 0.68) mm, (5.41 ± 1.01) mm, and (4.41 ± 0.57) mm, respectively. The grayscale features were diffusely hypoechoic with parallel linear hyperechoic striations. The mean elasticity modulus of the proximal, middle, and distal sites was (418.08 ± 43.13) kPa, (425.78 ± 47.14) kPa, and (407.79 ± 38.74) kPa, respectively. In the FH group, the thicknesses of the proximal, middle, and distal segments were (7.65 ± 3.09) mm, (11.46 ± 4.84) mm, and (8.14 ± 2.90) mm, respectively. The grayscale features were hypoechoic with linear hyperechoic disordered fibre distribution (92/94). Two of 94 Achilles tendons had considerable focal hypoechogenicity. Seventeen of 94 Achilles tendons had calcifications. In the FH group, the mean elasticity modulus of the proximal, middle, and distal segments were (294.86 ± 58.13) kPa, (280.93 ± 63.58) kPa, and (282.41 ± 56.47) kPa, respectively. Statistically significant differences were found between the Achilles tendons of healthy control participants and FH patients in the thicknesses and mean elasticity modulus at the proximal, middle and distal segments of the Achilles tendons (all P < 0.001).

CONCLUSIONS

Our results suggest that the grayscale features and SWE characteristics of the Achilles tendon provided complementary biomechanical information for quantitative assessment the Achilles tendon in patients with FH.

Application of expanded genetic analysis in the diagnosis of familial hypercholesterolemia in patients with very early-onset coronary artery disease

Background

Patients with monogenic familial hypercholesterolemia (FH) have high risk for coronary artery disease (CAD). A recent FH Expert Panel suggested that FH was underdiagnosed and undertreated which needs early diagnosis. Moreover, the proportion of DNA-confirmed FH patients hospitalized with very early-onset (≤ 35 years) CAD remains uncertain.

Methods

One hundred and five patients with age ≤ 35 years and LDL-C ≥ 3.4 mmol/L were tested for 9 genes (LDLR, APOB, PCSK9, APOE, STAP1, LIPA, LDLRAP1, ABCG5/8). Dutch Lipid Clinic Network (DLCN) and Simon Broome (SB) criteria for FH were also performed.

Results

The prevalence of genetically confirmed FH was 38.1% (n = 40) in 105 patients. DLCN categorized 26.7% patients to probable and definite FH while SB identified 17.1% of patients with possible to definite FH. Twenty-five (62.5%) and seventeen (42.5%) patients with pathogenic mutations were undiagnosed according to SB and DLCN criteria. FH variant carriers, especially homozygotes, had significantly higher plasma LDL-C levels. The best LDL-C threshold for genetically confirmed FH was 4.56 mmol/L in the present study.

Conclusions

FH is really a common cause for very young CAD patients (≤ 35 years) with a 38.1% of causative mutations in China and best LDL-C threshold for predicting mutations was 4.56 mmol/L. The underdiagnostic rate of clinical criteria was around 42.5–62.5%, suggesting that the expanded genetic testing could indeed promote the diagnosis of FH.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1737-7) contains supplementary material, which is available to authorized users.

Statin Treatments And Dosages In Children With Familial Hypercholesterolemia: Meta-Analysis

Background

Children with familial hypercholesterolemia may develop early endothelial damage leading to a high risk for the development of cardiovascular disease (CVD). Statins have been shown to be effective in lowering LDL cholesterol levels and cardiovascular events in adults. The effect of statin treatment in the pediatric population is not clearly demonstrated.

Objective

To systematically review the literature to evaluate the effects of different statins and dosages in total cholesterol levels in children and adolescents with familial hypercholesterolemia. We also aimed to evaluate statin safety in this group.

Methods

PubMed, EMBASE, Bireme, Web of Science, Cochrane Library, SciELO and LILACS databases, were searched for articles published from inception until February 2016. Two independent reviewers performed the quality assessment of the included studies. We performed a meta-analysis with random effects and inverse variance, and subgroup analyses were performed.

Results

Ten trials involving a total of 1543 patients met the inclusion criteria. Our study showed reductions in cholesterol levels according to the intensity of statin doses (high, intermediate and low): (-104.61 mg/dl, -67.60 mg/dl, -56.96 mg/dl) and in the low-density lipoprotein cholesterol level: [-105.03 mg/dl (95% CI -115.76, -94.30), I2 19.2%], [-67.85 mg/dl (95% CI -83.36, -52.35), I2 99.8%], [-58.97 mg/dl (95% CI -67.83, -50.11), I2 93.8%. The duration of statin therapy in the studies ranged from 8 to 104 weeks, precluding conclusions about long-term effects.

Conclusion

Statin treatment is efficient in lowering lipids in children with FH. There is need of large, long-term and randomized controlled trials to establish the long-term safety of statins.

Prevalence and pharmacologic management of familial hypercholesterolemia in an unselected contemporary cohort of patients with stable coronary artery disease

INTRODUCTION

Familial hypercholesterolemia (FH) is an inherited disorder characterized by elevated plasma levels of low-density lipoprotein cholesterol (LDL-C) associated with premature cardiovascular disease.

METHODS

Using the data from the START (STable Coronary Artery Diseases RegisTry) study, a nationwide, prospective survey on patients with stable coronary artery disease (CAD), we described prevalence and lipid lowering strategies commonly employed in these patients. The study population was divided into "definite/probable FH," defined as a Dutch Lipid Clinic Network (DLCN) score ≥6, "possible FH" with DLCN 3-5, and "unlikely FH" in presence of a DLCN <3.

RESULTS

Among the 4030 patients with the DLCN score available, 132 (3.3%) were classified as FH (2.3% with definite/probable and 1.0% with possible FH) and 3898 (96.7%) had unlikely FH. Patients with both definite/probable and possible FH were younger compared to patients not presenting FH. Mean on-treatment LDL-C levels were 107.8 ± 41.5, 84.4 ± 40.9, and 85.8 ± 32.3 (P < 0.0001) and a target of ≤70 mg/dL was reached in 10.9%, 30.0%, and 22.0% (P < 0.0001) of patents with definite/probable, possible FH, and unlikely FH, respectively. Statin therapy was prescribed in 85 (92.4%) patients with definite/probable FH, in 38 (95.0%) with possible FH, and in 3621 (92.9%) with unlikely FH (P = 0.86). The association of statin and ezetimibe, in absence of other lipid-lowering therapy, was more frequently used in patients with definite/probable FH compared to patients without FH (31.5% vs 17.5% vs 9.5%; P < 0.0001).

CONCLUSIONS

In this large cohort of consecutive patients with stable CAD, FH was highly prevalent and generally undertreated with lipid lowering therapies.

Clinical management of heterozygous familial hypercholesterolemia in a Polish outpatient metabolic clinic: a retrospective observational study

INTRODUCTION

There are currently no reports available from a Polish clinical practice on heterozygous familial hypercholesterolemia (HeFH) management. The aim of this study was to test the efficacy of HeFH hypolipidemic treatment in a Polish outpatient metabolic clinic according to treatment targets outlined in the European Atherosclerosis Society (EAS) and European Society of Cardiology (ESC) guidelines.

MATERIAL AND METHODS

This retrospective, observational study was performed on HeFH patients who attended their routine follow-up visits in the metabolic outpatient clinic in the period between April and September 2016. According to EAS/ESC guidelines, the goal and intensity of therapy were assigned individually for every patient based on cardiovascular (CV) risk (high or very high). The treatment target was achievement of low-density lipoprotein cholesterol (LDL-C) levels < 1.8 mmol/l for very high CV risk patients and < 2.6 mmol/l for high CV risk patients. A ≥ 50% decrease in LDL-C over the observation period was an additional outcome measure.

RESULTS

In the overall group of 222 HeFH patients (mean age: 55.2 ±16.2 years, 72% women), LDL-C levels decreased on average by 52.6% (p < 0.001). More than half of the patients were treated with the maximum tolerated dose of statins. A total of 25.2% of patients attained target levels of LDL-C and 55.9% attained a ≥ 50% reduction in its concentration. Despite therapy, significantly elevated post-follow-up levels of LDL-C (> 4.1 mmol/l) remained in 14% of all patients.

CONCLUSIONS

Hypolipidemic therapy according to EAS/ESC guidelines was suboptimal for a significant number of HeFH patients. Additional clinical management should be considered.

Genetic testing for a patient with suspected familial hypercholesterolaemia

Familial hypercholesterolaemia (FH) is a genetic condition that results in elevated low-density lipoprotein (LDL) cholesterol (LDL-C) levels with consequent increased risk for premature cardiovascular disease events. Although it is considered an autosomal-dominant genetic condition, the underlying genetic causes of FH can be complex. Currently most guidelines rely on clinical criteria to diagnose FH. But this approach has some pitfalls. We present a patient who was not formally diagnosed with FH using commonly used and well-accepted clinical criteria but via genetic testing was found to have a mutation for this disorder. This case brings to fore the challenges clinicians face in diagnosing and managing such unusual cases optimally. Through this case report, we hope to stimulate a debate among clinicians as well as other stakeholders regarding the need to develop more efficient ways of selecting patients for genetic testing in response to elevated LDL levels.

Selective and Regenerable Surface Based on β-Cyclodextrin for Low-Density Lipoprotein Adsorption

Cyclodextrins (CDs) are a family of cyclic oligosaccharides, whose unique hydrophilic outer surface and lipophilic central cavity facilitate the formation of inclusion complexes with various biomolecules, such as cholesterol and phospholipids, via multi-interactions. Low-density lipoprotein (LDL) is the main carrier of cholesterol in bloodstream and is associated with the progression of atherosclerosis. The surface of LDL is composed of a shell of phospholipids monolayer containing most of the free unesterified cholesterol as well as the single copy of apolipoprotein B-100. To date, various LDL adsorbents have been fabricated to interact with the biomolecules on LDL surface. Owing to its elegant structure, CD is considered to be a promising choice for preparation of more economical and effective LDL-adsorbing materials. Therefore, in this study, interaction between β-CD and LDL in solution was investigated by dynamic light scattering, circular dichroism, and ultraviolet spectroscopy. Further, a supramolecular surface based on β-CD was simply prepared by self-assembled monolayer on gold surface. The effect of hydrogen bond and the cavity of β-CD on the interaction between β-CD and LDL was particularly explored by surface plasmon resonance (SPR) analysis. The SPR results showed that such β-CD-modified surface exhibited good selectivity and could be largely regenerated by sodium dodecyl sulfate wash. This study may extend the understanding of the interaction between LDL and LDL adsorbent or the design and development of more efficient and lower-cost LDL adsorbents in the future.