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

Increasing the Detection of Familial Hypercholesterolaemia Using General Practice Electronic Databases

BACKGROUND

Familial hypercholesterolaemia (FH) is a common autosomal co-dominant condition that causes premature cardiovascular disease. Awareness of FH is poor and only 10-15% of the affected population is identified. Electronic health records provide an opportunity to increase detection and awareness in general practice OBJECTIVE: To determine whether a simple electronic extraction tool can increase detection of FH in general practice.

METHOD

An extraction tool applied to general practice electronic health records (EHR) to screen for FH, total cholesterol and low density lipoprotein cholesterol (LDL-c) levels in association with entered diagnostic criteria and demographic data in five general practices.

RESULTS

Of 157,290 active patients examined, 0.7% (n=1081) had an LDL-c>5.0 mmol/L representing 1 in 146 of active patients. An additional 0.8% (n=1276) patients were at possible risk of FH. Of those with an LDL-c>5.0 mmol/L 43.7% of patients had no record of being prescribed statins. Twenty patients (0.013%) had a clinical diagnosis of FH entered in the EHR.

CONCLUSIONS

Patients at high risk of FH can be identified by a simple electronic screening method in general practice. Clinical data entry is variable in general practice. Targeted screening enables clinical assessment of patients at risk of cardiovascular disease and using the DLCNS will enable primary care to increase identification of FH. Approximately one in five patients extracted using this method, are likely to have phenotypically probable FH, making it a useful screening tool.

Transitioning from pediatric to adult health care with familial hypercholesterolemia: Listening to young adult and parent voices

BACKGROUND

Young adults with familial hypercholesterolemia (FH) are at a critical period for establishing behaviors to promote future cardiovascular health.

OBJECTIVE

To examine challenges transitioning to adult care for young adults with FH and parents of FH-affected young adults in the context of 2 developmental tasks, transitioning from childhood to early adulthood and assuming responsibility for self-management of a chronic disorder.

METHODS

Semistructured, qualitative interviews were conducted with 12 young adults with FH and 12 parents of affected young adults from a pediatric subspecialty preventive cardiology program in a northeastern academic medical center. Analyses were conducted using a modified grounded theory framework.

RESULTS

Respondents identified 5 challenges: (1) recognizing oneself as a decision maker, (2) navigating emerging independence, (3) prioritizing treatment for a chronic disorder with limited signs and symptoms, (4) managing social implications of FH, and (5) finding credible resources for guidance. Both young adults and parents proposed similar recommendations for addressing these challenges, including the need for family and peer involvement to establish and maintain diet and exercise routines and to provide medication reminders. Systems-level recommendations included early engagement of adolescents in shared decision-making with health care team; providing credible, educational resources regarding FH; and using blood tests to track treatment efficacy.

CONCLUSION

Young adults with FH transitioning to adult care may benefit from explicit interventions to address challenges to establishing healthy lifestyle behaviors and medication adherence as they move toward being responsible for their medical care. Further research should explore the efficacy of recommended interventions.

The prevalence and prognostic importance of possible familial hypercholesterolemia in patients with myocardial infarction

AIMS

Familial hypercholesterolemia (FH) is a common genetic disorder causing accelerated atherosclerosis and premature cardiovascular disease. The aim of this study was to examine the prevalence and prognostic significance of possible FH in patients with myocardial infarction (MI).

METHODS AND RESULTS

By individual-level linkage of data from the Eastern Danish Heart Registry and national administrative registries, a study population of patients referred for coronary angiography due to MI was selected. The study population was divided into "unlikely FH" and "possible FH" based on the Dutch Lipid Clinic Network criteria, which included a plasma low-density lipoprotein cholesterol (LDL-C) and age for onset of cardiac disease. A score of ≥3 points was used as the cutpoint between the 2 groups. Among the study population of 13,174 MI patients, 1,281 (9.7%) had possible FH. These patients were younger (59.1 vs 65.7 years, P ≤ .0001), had similar levels of comorbidities, and were treated more aggressively with cholesterol-lowering drugs compared with patients with unlikely FH. During a median of 3.3 years of follow-up, the unadjusted and adjusted event rates of recurrent MI were higher in patients with possible FH compared with unlikely FH (16% vs 11%, adjusted hazard ratio 1.28, 95% CI 1.09-1.51, P = .003.). Differences in adjusted all-cause mortality were not statistically significant (17% vs 23%, adjusted hazard ratio 0.89 [0.74-1.04], P = .1).

CONCLUSION

We found that MI patients with possible FH have higher risk of recurrent MI but similar risk of mortality compared with unlikely FH patients. Further studies on secondary prevention are warranted.

LDL-Cholesterol: Standards of Treatment 2016: A German Perspective

Decreasing low-density lipoprotein cholesterol (LDL-C) is one of the few established and proven principles for the prevention and treatment of atherosclerosis. The higher the individual cardiovascular risk, the higher the benefit of lipid-lowering pharmacotherapy. Therefore, treatment options are chosen based on a patient's total cardiovascular risk. The latter depends not only on the levels of LDL-C but also on the presence of cardiovascular disease (CVD) and on the number and severity of other risk factors. Current guidelines recommend the lowering of LDL-C to 115 mg/dl (3 mmol/l) in patients with low and moderate risk. The LDL-C treatment target is <100 mg/dl (2.6 mmol/l) for patients at high risk and <70 mg/dl (1.8 mmol/l) for patients at very high risk. Although lifestyle measures remain a fundamental part of treatment, many patients require drug therapy to achieve their LDL-C targets. Statins are the drugs of choice, with other options including ezetimibe and the newly available monoclonal antibodies against PCSK9 (proprotein convertase subtilisin/kexin type 9). In some cases, bile acid-binding sequestrants and fibrates can also be considered. Nicotinic acid is no longer available in Germany. PCSK9 antibodies decrease LDL-C about 50-60 % and are well tolerated. Their effects on clinical endpoints are being investigated in large randomized trials. The aim of the present review is to summarize the current guidelines and treatment options for hypercholesterolemia. Moreover, we provide an appraisal of PCSK9 antibodies and propose their use in selected patient populations, particularly in those at very high cardiovascular risk whose LDL-C levels under maximally tolerated lipid-lowering therapy are significantly over their treatment target.

Molecular testing for familial hypercholesterolaemia-associated mutations in a UK-based cohort: development of an NGS-based method and comparison with multiplex polymerase chain reaction and oligonucleotide arrays

Background Detection of disease-associated mutations in patients with familial hypercholesterolaemia is crucial for early interventions to reduce risk of cardiovascular disease. Screening for these mutations represents a methodological challenge since more than 1200 different causal mutations in the low-density lipoprotein receptor has been identified. A number of methodological approaches have been developed for screening by clinical diagnostic laboratories. Methods Using primers targeting, the low-density lipoprotein receptor, apolipoprotein B, and proprotein convertase subtilisin/kexin type 9, we developed a novel Ion Torrent-based targeted re-sequencing method. We validated this in a West Midlands-UK small cohort of 58 patients screened in parallel with other mutation-targeting methods, such as multiplex polymerase chain reaction (Elucigene FH20), oligonucleotide arrays (Randox familial hypercholesterolaemia array) or the Illumina next-generation sequencing platform. Results In this small cohort, the next-generation sequencing method achieved excellent analytical performance characteristics and showed 100% and 89% concordance with the Randox array and the Elucigene FH20 assay. Investigation of the discrepant results identified two cases of mutation misclassification of the Elucigene FH20 multiplex polymerase chain reaction assay. A number of novel mutations not previously reported were also identified by the next-generation sequencing method. Conclusions Ion Torrent-based next-generation sequencing can deliver a suitable alternative for the molecular investigation of familial hypercholesterolaemia patients, especially when comprehensive mutation screening for rare or unknown mutations is required.

Regression of Achilles Tendon Xanthomas Evaluated by CT Scan After Hypolipidemic Treatment with Simvastatin

Familial hypercholesterolemia (FH) is a relatively common autosomal monogenic disease with dominant inheritance and threefold to fourfold increase in relative risk of cardiovascular death in untreated patients. For a “definitive” clinical diagnosis of FH the Simon Broome Register proposes the presence of tendon xanthomas as a key feature. However, detection of tendon xanthomas by physical examination is subjective and difficult to use for follow-up purposes. Several instrumental methods have been reported to be more sensitive than physical examination for the evaluation of xanthomas. The present case illustrates the usefulness of computed tomography (CT) to detect xanthomas in the Achilles tendons (XAT) and their regression in response to hypolipidemic drug treatment in a heterozygous FH patient. As XAT are atherosclerotic plaque-like depositions of lipids it is likely that their progression or regression follows the behavior of vascular atherosclerotic lesions.

Cascade Screening for Familial Hypercholesterolemia: PCR Methods with Melting-Curve Genotyping for the Targeted Molecular Detection of Apolipoprotein B and LDL Receptor Gene Mutations to Identify Affected Relatives

BACKGROUND

A key objective of the UK National Institute for Health and Care Excellence (NICE) pathway for diagnosis of familial hypercholesterolemia (FH) is the identification of affected relatives of index cases through cascade screening. At present, there is no systematic appraisal of available methodological options to identify the appropriate diagnostic testing protocol that would allow cost-effective cascade genetic screening. The majority of FH-causing mutations identified in the LDL receptor (LDLR) or apolipoprotein B (APOB) genes are single-nucleotide changes. This pattern of mutations suggests that PCR methods using melting curve-based genotyping might offer a convenient methodological approach for screening relatives.

METHODS

We developed and validated one-tube PCR methods for the mutations APOB c.10580G>A (p.Arg3527Gln), LDLR c.1474G>A (p.Asp492Asn), and c.2054C>T (p.Pro685Leu) and 3 novel LDLR mutations identified in the Coventry and Warwickshire population: LDLR c.1567G>C (p.Val523Leu), c.487dupC (p.Gln163Profs17), and c.647G>C (p.Cys216Ser).

RESULTS

These methods successfully amplified target sequence from genomic DNA extracted from either peripheral blood or saliva. They also demonstrated acceptable analytical performance characteristics (specificity of amplification, repeatability, and reproducibility) over a wide range of DNA concentrations and purity. This approach was used for cascade testing of relatives of index FH cases with confirmed mutations and identified family members with high plasma LDL cholesterol as heterozygous for disruptive alleles.

CONCLUSIONS

Our study generates proof-of-concept evidence of methods suitable for detecting single nucleotide substitutions and insertions that can deliver reliable, easy, low-cost, and rapid family screening of FH patients and can be adopted by nonspecialist molecular diagnostic laboratories.

Association between physical activity, adiposity, and lipid abnormalities in children with familial hyperlipidemia

BACKGROUND

The benefits of physical activity in children have been studied extensively; however, its role in children with familial hyperlipidemia (FH) is unknown.

OBJECTIVE

To determine associations between physical activity, adiposity, and lipid profiles in children with FH.

DESIGN

A physical activity questionnaire was completed by 147 children with FH. Correlations between activity levels, body mass index (BMI), and fasting lipid profiles were determined.

RESULTS

The mean age of patients was 12.5+/-3.2 years with a mean total cholesterol of 6.17 mmol/l (238 mg/dl), low-density lipoprotein-cholesterol of 4.43 (171), high-density lipoprotein-cholesterol of 1.08 (42), and triglyceride levels of 1.51 (134). Patients had greater weight for height indices than normal, with a mean BMI z score of +0.90+/-1.30 SD (P<0.001 versus normal), and with 21% of the participants being more than 2 SD above normal. Higher BMI z scores significantly correlated with higher triglyceride levels (r=0.33; P<0.0001) and greater time spent in sedentary pursuits (r=0.24; P=0.004), in particular watching television (r=0.26; P=0.003). The increased time that other family members spent in physical activity significantly correlated with a lower BMI z score (r=-0.21; P=0.01) of the patient and greater time spent in physical activity (r=0.24; P=0.003). There was no association between patients' physical activity levels and lipid profile or BMI.

CONCLUSION

Similar to the general population, children with FH are also at risk of becoming overweight. Increased adiposity significantly correlated with the greater sedentary activities of the patient, lower physical activities of the family, and higher triglyceride levels. Physical activity levels of the patient correlated with family activity levels.

Pharmacoeconomics of PCSK9 inhibitors in 103 hypercholesterolemic patients referred for diagnosis and treatment to a cholesterol treatment center

Background

PCSK9 inhibitor therapy has been approved by the FDA as an adjunct to diet-maximal tolerated cholesterol lowering drug therapy for adults with heterozygous familial hypercholesterolemia (HeFH) or clinical atherosclerotic cardiovascular disease (ASCVD) with suboptimal LDL cholesterol (LDLC) lowering despite maximal diet-drug therapy. With an estimated ~24million of US hypercholesterolemic patients potentially eligible for PCSK9 inhibitors, costing ~ $14,300/patient/year, it is important to assess health-care savings arising from PCSK9 inhibitors vs ASCVD cost.

Methods

In 103 patients with HeFH, and/or ASCVD and/or suboptimal LDLC lowering despite maximally tolerated diet-drug therapy, we assessed pharmacoeconomics of PCSK9 inhibitor therapy with lowering of LDLC. For HeFH diagnosis, we applied Simon Broome’s or WHO Dutch Lipid Criteria (score >8). Estimates of direct and indirect costs for ASCVD events were calculated using American Heart Association (AHA), U.S. DHHS, Healthcare Bluebook, and BMC Health Services Research databases. We used the ACC/AHA 10-year ASCVD risk calculator to estimate 10-year ASCVD risk and estimated corresponding direct and indirect costs. Assuming a 50 % reduction in ASCVD events on PCSK9 inhibitors, we calculated direct and indirect health-care savings.

Results

We started 103 patients (58 [56 %] women and 45 [44 %] men), on either alirocumab (62 %) or evolocumab (38 %), median age 63, BMI 29.0, and LDLC 149 mg/dl. Of the 103 patients, 28 had both HeFH and ASCVD, 33 with only ASCVD, 33 with only HeFH, and 9 had neither. Of the 103 patients, 61 had a first ASCVD event at median age 55 and on best tolerated cholesterol-lowering therapy median LDLC was 137 mg/dl. In these 61 patients, total direct costs attributable to ASCVD were $8,904,361 ($4,328,623 direct, $4,575,738 indirect), the median 10-year risk of a new CVD event was calculated to be 13.1 % with total cost $1,654,758. Assuming a 50 % reduction in ASCVD events on PCSK9 inhibitors in our 61 patients, $4,452,180 would have been saved in the past; and future 10-year savings would be $1,123,345.

Conclusion

In the 61 CVD patients, net costs/patient/year were estimated to be $7,000 in the past, with future 10-year intervention net costs/patient/year being $12,459, both below the $50,000/year quality adjusted life-year gained by PCSK9 inhibitor therapy.

US physician practices for diagnosing familial hypercholesterolemia: data from the CASCADE-FH registry

BACKGROUND

In the US familial hypercholesterolemia (FH), patients are underidentified, despite an estimated prevalence of 1:200 to 1:500. Criteria to identify FH patients include Simon Broome, Dutch Lipid Clinic Network (DLCN), or Make Early Diagnosis to Prevent Early Deaths (MEDPED). The use of these criteria in US clinical practices remains unclear.

OBJECTIVE

To characterize the FH diagnostic criteria applied by US lipid specialists participating in the FH Foundation's CASCADE FH (CAscade SCreening for Awareness and DEtection of Familial Hypercholesterolemia) patient registry.

METHODS

We performed an observational, cross-sectional analysis of diagnostic criteria chosen for each adult patient, both overall and by baseline patient characteristics, at 15 clinical sites that had contributed data to the registry as of September 8, 2015. A sample of 1867 FH adults was analyzed. The median age at FH diagnosis was 50 years, and the median pretreatment low-density lipoprotein cholesterol (LDL-C) value was 238 mg/dL. The main outcome was the diagnostic criteria chosen. Diagnostic criteria were divided into five nonexclusive categories: "clinical diagnosis," MEDPED, Simon Broome, DLCN, and other.

RESULTS

Most adults enrolled in CASCADE FH (55.0%) received a "clinical diagnosis." The most commonly used formal criteria was Simon-Broome only (21%), followed by multiple diagnostic criteria (16%), MEDPED only (7%), DLCN only (1%), and other (0.5%), P < .0001. Of the patients with only a "clinical diagnosis," 93% would have met criteria for Simon Broome, DLCN, or MEDPED based on the data available in the registry.

CONCLUSIONS

Our findings demonstrate heterogeneity in the application of FH diagnostic criteria in the United States. A nationwide consensus definition may lead to better identification, earlier treatment, and ultimately CHD prevention.

Knowledge gaps in the management of familial hypercholesterolaemia. A UK based survey

BACKGROUND AND AIMS

Untreated individuals with familial hypercholesterolaemia (FH) are at increased risk of developing premature cardiovascular disease (CVD). Early diagnosis and treatment can result in a normal life expectancy. A recent survey commissioned by the European Atherosclerosis Society (EAS) reported a lack of awareness of FH in the general population. We conducted a survey to assess knowledge among healthcare professionals involved in the assessment and management of cardiovascular risk and disease in the United Kingdom.

METHODS

A survey designed to assess knowledge of diagnostic criteria, risk assessment, the role of cascade screening, and management options for patients with FH was distributed to 1000 healthcare professionals (response rate 44.3%). The same survey was redistributed following attendance at an educational session on FH.

RESULTS

151 respondents (40.5%) reported having patients under their care who would meet the diagnostic criteria for FH, but just 61.4% recognized that cardiovascular risk estimation tools cannot be applied in FH, and only 22.3% understood the relative risk of premature CVD compared to the general population. Similarly, just 65.9% were aware of recommendations regarding cascade screening.

CONCLUSIONS

The prevalence and associated risk of FH continue to be underestimated, and knowledge of diagnostic criteria and treatment options is suboptimal. These results support the recent Consensus Statement of the EAS and production of quality standards by the National Institute for Health and Care Excellence. Further work is required to formulate interventions to improve FH awareness and knowledge, and to determine the effect these interventions have on patient outcomes.

Translational Research for Improving the Care of Familial Hypercholesterolemia: The "Ten Countries Study" and Beyond

Familial hypercholesterolemia (FH) is the most common and serious form of inherited hyperlipidaemia. Dominantly inherited with high penetrance, untreated FH leads to premature death from coronary artery disease due to accelerated atherosclerosis from birth. Despite its importance, there is still a major shortfall in awareness, detection and treatment of FH worldwide. International models of care for FH have recently been published, but their effective implementation requires the garnering of more knowledge about the condition. The "Ten Countries Study" aims to investigate diagnostic, epidemiological and service aspects, as well as physician practices and patient experiences of FH in several countries in the Asia-Pacific Region and the Southern Hemisphere. Five observational studies are being undertaken that will systematically investigate the following aspects of FH: the phenotypic predictors of low-density lipoprotein receptor mutations, the point prevalence in available community populations, current knowledge and clinical practices among primary care physicians, availability and utilisation of services and facilities, and patient perceptions and personal experiences of the condition. The information gathered will inform better clinical practice and will enable the development of country-specific models of care for FH.

Familial hypercholesterolaemia: cholesterol efflux and coronary disease

BACKGROUND

Coronary heart disease (CHD) risk inversely associates with levels of high-density lipoprotein cholesterol (HDL-C). The protective effect of HDL is thought to depend on its functionality, such as its ability to induce cholesterol efflux.

MATERIALS AND METHODS

We compared plasma cholesterol efflux capacity between male familial hypercholesterolaemia (FH) patients with and without CHD relative to their non-FH brothers, and examined HDL constituents including sphingosine-1-phosphate (S1P) and its carrier apolipoprotein M (apoM).

RESULTS

Seven FH patients were asymptomatic and six had experienced a cardiac event at a mean age of 39 years. Compared to their non-FH brothers, cholesterol efflux from macrophages to plasma from the FH patients without CHD was 16 ± 22% (mean ± SD) higher and to plasma from the FH patients with CHD was 7 ± 8% lower (P = 0·03, CHD vs. non-CHD). Compared to their non-FH brothers, FH patients without CHD displayed significantly higher levels of HDL-cholesterol, HDL-S1P and apoM, while FH patients with CHD displayed lower levels than their non-FH brothers.

CONCLUSIONS

A higher plasma cholesterol efflux capacity and higher S1P and apoM content of HDL in asymptomatic FH patients may play a role in their apparent protection from premature CHD.

Interpretative comments specifically suggesting specialist referral increase the detection of familial hypercholesterolaemia

Familial hypercholesterolaemia (FH) is an under-diagnosed inherited condition characterised by elevated low density lipoprotein (LDL)-cholesterol and premature coronary artery disease. The requesting general practitioner of individuals with extremely elevated LDL-cholesterol measured by St John of God Pathology receives an interpretative comment on the lipid results highlighting possible FH. We sought to determine whether specifically recommending referral to the regional Lipid Disorders Clinic (LDC) increased referral and FH detection rates. A prospective case-control study of individuals with LDL-cholesterol ≥6.5 mmol/L was conducted. All individuals received an interpretative comment highlighting the possibility of FH. The cases comment also suggested LDC referral, and a subset of cases received the LDC's fax number (fax-cases) in addition. There were 231 individuals with an LDL-cholesterol ≥6.5 mmol/L; 96 (42%) controls and 135 (58%) cases, of which 99 were fax-cases. Twenty-four (18%) cases were referred to clinic compared with eight (8%) controls (p = 0.035). After specialist review and genetic testing, four probable and four definite FH individuals were detected amongst controls, compared with seven possible, eight probable and nine definite FH amongst cases. Genetic testing was performed in 31 (94%) individuals, 13 (42%) had a causative mutation identified. Interpretative commenting specifically recommending specialist review augments the detection of FH in the community.

Rationale and Design of the PROSPECTIVE Trial: Probucol Trial for Secondary Prevention of Atherosclerotic Events in Patients with Prior Coronary Heart Disease

BACKGROUND

Reduction of serum LDL-cholesterol by statins was shown to improve clinical outcomes in patients with coronary heart disease (CHD). Although intensive statin therapy significantly reduced cardiovascular risks, atherosclerotic cardiovascular events have not been completely prevented. Therefore, effective pharmacologic therapy is necessary to improve "residual risks" in combination with statins. Probucol has a potent antioxidative effect, inhibits the oxidation of LDL, and reduces xanthomas. Probucol Trial for Secondary Prevention of Atherosclerotic Events in Patients with Prior Coronary Heart Disease (PROSPECTIVE) is a multicenter, randomized, prospective study designed to test the hypothesis that the addition of probucol to other lipid-lowering drugs will prevent cerebro- and cardiovascular events in patients with prior coronary events and high LDL cholesterol levels.

STUDY DESIGN

The study will recruit approximately 860 patients with a prior CHD and dyslipidemia with LDL-C level ≥140 mg/dl without any medication and those treated with any lipid-lowering drugs with LDL-C level ≥100 mg/dl. Lipid-lowering agents are continuously administered during the study period in control group, and probucol (500 mg/day, 250 mg twice daily) is added to lipid-lowering therapy in the test group. The efficacy and safety of probucol with regard to the prevention of cerebro- and cardiovascular events and the intima-media thickness of carotid arteries as a surrogate marker will be evaluated.

SUMMARY

PROSPECTIVE will determine whether the addition of probucol to other lipid-lowering drugs improves cerebro- and cardiovascular outcomes in patients with prior coronary heart disease. Furthermore, the safety of a long-term treatment with probucol will be clarified.

My Approach to the Patient With Familial Hypercholesterolemia

Familial hypercholesterolemia (FH), a relatively common Mendelian genetic disorder, is associated with a dramatically increased lifetime risk of premature atherosclerotic cardiovascular disease due to elevated plasma low-density lipoprotein cholesterol (LDL-C) levels. The diagnosis of FH is based on clinical presentation or genetic testing. Early identification of patients with FH is of great public health importance because preventive strategies can lower the absolute lifetime cardiovascular risk and screening can detect affected relatives. However, low awareness, detection, and control of FH pose hurdles in the prevention of FH-related cardiovascular events. Of the estimated 0.65 million to 1 million patients with FH in the United States, less than 10% carry a diagnosis of FH. Based on registry data, a substantial proportion of patients with FH are receiving no or inadequate lipid-lowering therapy. Statins remain the mainstay of treatment for patients with FH. Lipoprotein apheresis and newly approved lipid-lowering drugs are valuable adjuncts to statin therapy, particularly when the LDL-C-lowering response is suboptimal. Monoclonal antibodies targeting proprotein convertase subtilisin/kexin type 9 provide an additional approximately 60% lowering of LDL-C levels and are approved for use in patients with FH. For homozygous FH, 2 new drugs that work independent of the LDL receptor pathway are available: an apolipoprotein B antisense oligonucleotide (mipomersen) and a microsomal triglyceride transfer protein inhibitor (lomitapide). This review attempts to critically examine the available data to provide a summary of the current evidence for managing patients with FH, including screening, diagnosis, treatment, and surveillance.

Improving detection of familial hypercholesterolaemia in primary care using electronic audit and nurse-led clinics

RATIONALE, AIMS AND OBJECTIVES

In the UK fewer than 15% of familial hypercholesterolemia (FH) cases are diagnosed, representing a major gap in coronary heart disease prevention. We wished to support primary care doctors within the Medway Clinical Commissioning Group (CCG) to implement NICE guidance (CG71) and consider the possibility of FH in adults who have raised total cholesterol concentrations, thereby improving the detection of people with FH.

METHODS

Utilizing clinical decision support software (Audit+) we developed an FH Audit Tool and implemented a systematic audit of electronic medical records within GP practices, first identifying all patients diagnosed with FH or possible FH and next electronically flagging patients with a recorded total cholesterol of >7.5 mmol L(-1) or LDL-C > 4.9 mmol L(-1) (in adults), for further assessment. After a 2-year period, a nurse-led clinic was introduced to screen more intensely for new FH index cases. We evaluated if these interventions increased the prevalence of FH closer to the expected prevalence from epidemiological studies.

RESULTS

The baseline prevalence of FH within Medway CCG was 0.13% (1 in 750 persons). After 2 years, the recorded prevalence of diagnosed FH increased by 0.09% to 0.22% (1 in 450 persons). The nurse advisor programme ran for 9 months (October 2013-July 2014) and during this time, the recorded prevalence of patients diagnosed with FH increased to 0.28% (1 in 357 persons) and the prevalence of patients 'at risk and unscreened' reduced from 0.58% to 0.14%.

CONCLUSIONS

Our study shows that two simple interventions increased the detection of FH. This systematic yet simple electronic case-finding programme with nurse-led review allowed the identification of new index cases, more than doubling the recorded prevalence of detected disease to 1 in 357 (0.28%). This study shows that primary care has an important role in identifying patients with this condition.

[PCSK9 inhibitors : Recommendations for patient selection]

The 2 or 4‑week subcutaneous therapy with the recently approved antibodies alirocumab and evolocumab for inhibition of proprotein convertase subtilisin-kexin type 9 (PCSK9) reduces low-density lipoprotein cholesterol (LDL-C) in addition to statins and ezetimibe by 50-60 %. The therapy is well-tolerated. The safety profile in the published studies is comparable to placebo. Outcome data and information on long-term safety and the influence on cardiovascular events are not yet available but the results of several large trials are expected in 2016-2018. At present (spring 2016) PCSK9 inhibitors represent an option for selected patients with a high cardiovascular risk and high LDL-C despite treatment with the maximum tolerated oral lipid-lowering therapy. This group includes selected patients with familial hypercholesterolemia and high-risk individuals with statin-associated muscle symptoms (SAMS).

Familial hypercholesterolemia in a large ambulatory population: Statin use, optimal treatment, and identification for advanced medical therapies

BACKGROUND

Familial hypercholesterolemia (FH) is an autosomal dominant genetic disease resulting in elevated serum low-density lipoprotein cholesterol (LDL-C) levels. Patients with FH have a very high lifetime risk of cardiovascular disease, but FH often goes unrecognized in clinical care. New treatments including PCSK9 inhibitors are now available for this population, and the use of the electronic record may be able to help identify potential patients for therapy.

OBJECTIVES

The goal of this study was to determine the period prevalence of FH in a large ambulatory care population, including the homozygous form. In addition, use of cholesterol lowering therapy in individuals with FH was characterized.

METHODS

A retrospective analysis was carried out among patients seen in an upper Midwest health care system between 2009 and 2012. In a search of electronic health records (EHR) and using the current National Lipid Association guidelines, FH patients (including homozygous cases) were identified based on age and highest LDL-C. Statin therapy was characterized according to current FH treatment guidelines.

RESULTS

There were 391,166 individuals with available measures during the study timeframe. Of these, 841 were identified as having probable HeFH, representing a prevalence of 0.21% (about 1 in 470 patients) in this population. HoFH was identified as probable in 6 patients. For the total group, two-thirds of FH patients were on a statin, but only half were treated adequately. The remaining one-third of FH patients were not on statin therapy, with only 27% of those not on statin therapy having a documented statin intolerance.

CONCLUSIONS

FH is often underdiagnosed and suboptimally treated in clinical practice. Statin therapy in this population rarely went beyond low-moderate doses. These findings support EHR-based population health efforts to initiate an FH cascade-screening model and ensure higher quality care for this high-risk population and identify those who may benefit from advanced therapy.

Cardiovascular risk stratification in familial hypercholesterolaemia

Familial hypercholesterolaemia (FH) is a common autosomal-dominant disorder in most European countries. Patients with FH are characterised by a raised level of low-density lipoprotein cholesterol and a high risk of premature coronary heart disease (CHD). Currently there is no consensus regarding the clinical utility to predict future coronary events or testing for the presence of subclinical atherosclerotic disease in asymptomatic patients with FH. Family screening of patients with FH as recommended by the UK National Institute of Health and Care Excellence guideline would result in finding many young individuals with a diagnosis of FH who are clinically asymptomatic. The traditional CHD risk scores, that is, the Framingham score, are insufficient in risk prediction in this group of young individuals. In addition, a better understanding of the genetic aetiology of the FH phenotype and CHD risk in monogenic FH and polygenic hypercholesterolaemia is needed. Non-invasive imaging methods such as carotid intima-media thickness measurement might produce more reliable information in finding high-risk patients with FH. The potential market authorisation of novel therapeutic agents such as PCSK9 monoclonal inhibitors makes it essential to have a better screening programme to prioritise the candidates for treatment with the most severe form of FH and at higher risk of coronary events. The utility of new imaging techniques and new cardiovascular biomarkers remains to be determined in prospective trials.

Characteristics and Vascular Complications of Familial Hypercholesterolemia in Korea

Familial hypercholesterolemia (FH) is presently an important health issue worldwide. This condition shows phenotypic and genetic variations among affected people, and clinical and genetic data on FH are critical for effective diagnosis and management. Korean FH patients have relatively low levels of cholesterol and prevalence of xanthoma than patients from other countries, as determined by previous studies. The best predictive value of low-density lipoprotein cholesterol (LDL-C) for pathogenic mutations is suggested as 225 mg/dL. Many known and novel mutations on LDLR and some on APOB or PCSK9 have been identified in one-third of clinically diagnosed probands, and their locations on genes varied. Coronary artery disease was reported in 28% Korean FH patients, and traditional cardiovascular risk factors were associated with this complication. Aortic valve changes were also prevalent. However, the achievement rate of LDL-C target using lipid-lowering therapy is not satisfactory and is only 21%-44%. A further expanded registry and additional analysis may provide a more useful clinical tool for the diagnosis and treatment of Korean FH patients.

PCSK9 antibodies: A new class of lipid-lowering drugs

The serine protease proprotein convertase subtilisin/kexin type 9 (PCSK9) binds to the low-density lipoprotein (LDL) receptor (LDLR) and directs it to the lysosome for degradation. This results in decreased numbers of LDLR available on the cell surface to bind LDL particles and remove them from the circulation and a subsequent increase in circulating LDL-cholesterol (LDL-C) concentrations. Since the role PCSK9 plays in LDL-C metabolism has been discovered in 2003, there have been major efforts in finding efficient and safe methods to inhibit it. Amongst those, the PCSK9 antibodies are the furthest in development, with multiple phase III and cardiovascular endpoint trials already underway. These fully human monoclonal antibodies have been extensively studied in a wide range of subjects such as in those with statin intolerance, as add-on to statin therapy, as monotherapy and in patients with familial hypercholesterolemia. PCSK9 antibodies have shown to be associated with a consistent robust additional decrease in LDL-C concentrations of around 50-70%. If the safety data from the ongoing phase III trials remain as reassuring as the data available till now, PCSK9 antibodies are going to offer a new, powerful therapeutic option to decrease LDL-C concentrations and hopefully cardiovascular risk.

Successful Direct Adsorption of Lipoproteins (DALI) Apheresis During Pregnancy in an Omani Woman with Homozygous Familial Hypercholesterolemia

We report our experience with Direct Adsorption of Lipoproteins (DALI) apheresis in an Omani pregnant woman affected by homozygous familial hypercholesterolemia. To the best of our knowledge this is the first successful pregnancy treated with DALI apheresis. The patient had a history of coronary artery disease, supra-aortic valvular stenosis and severe carotid artery disease with right carotid artery stenting. She was on a regular biweekly DALI apheresis since 2008. In May 2013, she became pregnant and rosuvastatin and ezetimibe were stopped while she continued on DALI apheresis biweekly. This treatment during pregnancy was successful with no major complications. The average low-density lipoprotein cholesterol reduction during therapy was 50%. She spontaneously delivered a healthy male infant (2,400 g) at 37 weeks. We showed that DALI apheresis therapy was safe during pregnancy with a good outcome for both mother and neonate.

The hinterland of familial hypercholesterolaemia: what do we not know?

PURPOSE OF REVIEW

Familial hypercholesterolaemia is the commonest autosomal dominant disorder in man, but many questions about familial hypercholesterolaemia remain to be answered. Guidelines are increasing in importance as healthcare becomes standardized. The review suggests areas that require more investigation or where pertinent guidelines may need to be reviewed.

RECENT FINDINGS

Familial hypercholesterolaemia is commoner than previously thought, but its epidemiology needs further investigation against a background of changing environmental and lifestyle factors that may bear on its phenotypic expression. Screening for familial hypercholesterolaemia may be more difficult than might be thought as cascade testing may not capture all cases effectively and universal screening appears compelling, but requires testing and evaluation. Cardiovascular disease guidelines are moving to being risk based, but familial hypercholesterolaemia stands alone as defined by large database of lipids-cholesterol criteria. A risk-based approach may need to be considered for familial hypercholesterolaemia, but a good evidence base is required. The effects of older therapies on prognosis in familial hypercholesterolaemia are based on surrogate as opposed to cardiovascular disease outcomes. Novel efficacious but expensive therapies are on the horizon, but no specific outcome trials in familial hypercholesterolaemia are planned and they may not be cost-effective outside very severe familial hypercholesterolaemia. Further research is also required to trial and test different models of care for familial hypercholesterolaemia.

SUMMARY

Despite familial hypercholesterolaemia being a common genetic condition, aspects of basic epidemiology, risk assessment, treatment, and models of care remain uncertain.

Development of Aortic Valve Disease in Familial Hypercholesterolemic Swine: Implications for Elucidating Disease Etiology

Background

Familial hypercholesterolemia (FH) is a prevalent hereditary disease associated with increased atherosclerosis and calcific aortic valve disease (CAVD). However, in both FH and non‐FH individuals, the role of hypercholesterolemia in the development of CAVD is poorly understood. This study used Rapacz FH (RFH) swine, an established model of human FH, to investigate the role of hypercholesterolemia alone in the initiation and progression of CAVD. The valves of RFH swine have not previously been examined.

Methods and Results

Aortic valve leaflets were isolated from wild‐type (0.25‐ and 1‐year‐old) and RFH (0.25‐, 1‐, 2‐, and 3‐year‐old) swine. Adult RFH animals exhibited numerous hallmarks of early CAVD. Significant leaflet thickening was found in adult RFH swine, accompanied by extensive extracellular matrix remodeling, including proteoglycan enrichment, collagen disorganization, and elastin fragmentation. Increased lipid oxidation and infiltration of macrophages were also evident in adult RFH swine. Intracardiac echocardiography revealed mild aortic valve sclerosis in some of the adult RFH animals, but unimpaired valve function. Microarray analysis of valves from adult versus juvenile RFH animals revealed significant upregulation of inflammation‐related genes, as well as several commonalities with atherosclerosis and overlap with human CAVD.

Conclusions

Adult RFH swine exhibited several hallmarks of early human CAVD, suggesting potential for these animals to help elucidate CAVD etiology in both FH and non‐FH individuals. The development of advanced atherosclerotic lesions, but only early‐stage CAVD, in RFH swine supports the hypothesis of an initial shared disease process, with additional stimulation necessary for further progression of CAVD.

Screening for Familial Hypercholesterolemia in Children: What Can We Learn From Adult Screening Programs?

Familial hypercholesterolemia (FH), an autosomal dominant atherosclerotic disease, is a common monogenic subtype of cardiovascular disease. Patients with FH suffer an increased risk of early onset heart disease. Early identification of abnormally elevated cholesterol signpost clinicians to interventions that will significantly decrease risk of related morbidity and mortality. Cascade genetic testing can subsequently identify at-risk relatives. Accordingly, a number of screening approaches have been implemented for FH in countries including the UK and the Netherlands. However, incomplete identification of cases remains a challenge. Moreover, the potential for early intervention is now raising questions about the value of implementing universal cholesterol screening approaches that focus on children. In this report, we briefly discuss the potential benefit of such screening. Additionally, we submit that ever increasing genome technological capability will force a discussion of including genetic tests in these screening programs. We discuss the opportunities and challenges presented by such an approach. We close with recommendations that the success of such screening endeavors will rely on a better integrated practice model in public health genomics that bridges stakeholders including practitioners in primary care, clinical genetics and public health.

Small, dense high-density lipoprotein 3 particles exhibit defective antioxidative and anti-inflammatory function in familial hypercholesterolemia: Partial correction by low-density lipoprotein apheresis

BACKGROUND

Familial hypercholesterolemia (FH) features elevated oxidative stress and accelerated atherosclerosis driven by elevated levels of atherogenic lipoproteins relative to subnormal levels of atheroprotective high-density lipoprotein (HDL). Small, dense HDL3 potently protects low-density lipoprotein (LDL) against proinflammatory oxidative damage.

OBJECTIVE

To determine whether antioxidative and/or anti-inflammatory activities of HDL are defective in FH and whether such defects are corrected by LDL apheresis.

METHODS

Antioxidative and antiinflammatory activities of HDL were evaluated as protection of reference LDL from oxidative stress and capacity to prevent accumulation of proinflammatory oxidised lipids, respectively. Lipid surface rigidity of HDL was assessed using a fluorescent probe. HDL components were measured by analytical approaches. Systemic oxidative stress was characterized as plasma 8-isoprostanes.

RESULTS

Pre-LDL-apheresis, FH patients (n = 10) exhibited elevated systemic oxidative stress (3.3-fold, P < 0.001) vs. sex- and age-matched normolipidemic controls (n = 10). Both antioxidative and antiinflammatory activity of HDL3 were impaired (up to -91%, P < 0.01) in FH. Sphingomyelin and saturated fatty acid contents were elevated in FH HDL3, resulting in enhanced lipid surface rigidity. The surface lipid content (phospholipids, free cholesterol) was reduced in FH (up to -15%, P < 0.001), whereas content of core lipids (cholesteryl esters, triglycerides) was elevated (up to +17%, P < 0.001). Molar apolipoprotein A-I content of HDL3 was subnormal in FH. A single LDL-apheresis session partially corrected (by up to 76%) deficient HDL antiatherogenic activities, attenuated systemic oxidative stress and partially normalised both the lipid composition and surface rigidity of HDL particles.

CONCLUSIONS

FH features elevated oxidative stress and deficient antioxidative and anti-inflammatory activities of small, dense HDL3; such functional deficiency is intimately linked to anomalies in lipid and protein composition, which may impair the capacity of HDL to acquire and inactivate oxidized lipids.

Challenges in the care of familial hypercholesterolemia: a community care perspective

Familial hyperchoelsterolaemia (FH) remains under-diagnosed and under-treated in the community setting. Earlier evidence suggested a prevalence of 1:500 worldwide but newer evidence suggests it is more common. Less than 15% of FH patients are ever diagnosed, with children and young adults rarely tested despite having the most to gain given their lifetime exposure. Increasing awareness among primary care teams is critical to improve the detection profile for FH. Cascade testing in the community setting needs a sustainable approach to be developed to facilitate family tracing of index cases. The use of the Dutch Lipid Clinic Network Criteria score to facilitate a phenotypic diagnosis is the preferred approach adopted in Australia and eliminates the need to undertake genetic testing for all suspected FH cases.

New developments in atherosclerosis: clinical potential of PCSK9 inhibition

Pro-protein convertase subtilisin/kexin type 9 (PCSK9) is a secreted 692-amino acid protein that binds surface low-density lipoprotein (LDL) receptor (LDLR) and targets it toward lysosomal degradation. As a consequence, the number of LDLRs at the cell surface is decreased, and LDL-cholesterol (LDL-C) clearance is reduced, a phenomenon that is magnified by gain-of-function mutations of PCSK9. In contrast, loss-of-function mutations of PCSK9 result in increased surface LDLR and improved LDL-C clearance. This provides the rationale for targeting PCSK9 in hypercholesterolemic subjects as a means to lower LDL-C levels. Monoclonal antibodies (mAbs) against PCSK9 that block its interaction with the LDLR have been developed in the past decade. Two companies have recently received the approval for their anti-PCSK9 mAbs by the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) Regeneron/Sanofi, with alirocumab (commercial name – PRALUENT^®) and, Amgen with evolocumab (commercial name – Repatha™). The introduction of anti-PCSK9 mAbs will provide an alternative therapeutic strategy to address many of the unmet needs of current lipid-lowering therapies, such as inability to achieve goal LDL-C level, or intolerance and aversion to statins. This review will focus on the kinetics of PCSK9, pharmacokinetics and pharmacodynamics of anti-PCSK9 mAbs, and recent data linking PCSK9 and anti-PCSK9 mAbs to cardiovascular events. Moreover, it will highlight the unanswered questions that still need to be addressed in order to understand the physiologic function, kinetics, and dynamics of PCSK9.

Homozygous Familial Hypercholesterolemia Associated with Symmetric Subcutaneous Lipomatosis

Homozygous familial hypercholesterolemia is an autosomal dominant disorder of lipid metabolism, characterized by reduced clearance of low-density lipoprotein-cholesterol and a high risk of rapid development of cardiovascular diseases. Its incidence is relatively rare and estimated to be one in one million in general populations. Here, we report homozygous familial hypercholesterolemia in two Egyptian young siblings, presented with cutaneous, tendinous xanthomas, and corneal arcus. One of them has symmetric subcutaneous lipomatosis, which has not been reported before in association with familial hypercholesterolemia.

Systematic analysis of variants related to familial hypercholesterolemia in families with premature myocardial infarction

Familial hypercholesterolemia (FH) is an oligogenic disorder characterized by markedly elevated low-density lipoprotein cholesterol (LDLC) levels. Variants in four genes have been reported to cause the classical autosomal-dominant form of the disease. FH is largely under-diagnosed in European countries. As FH increases the risk for coronary artery disease (CAD) and myocardial infarction (MI), it might be specifically overlooked in the large number of such patients. Here, we systematically examined the frequency of potential FH-causing variants by exome sequencing in 255 German patients with premature MI and a positive family history for CAD. We further performed co-segregation analyses in an average of 5.5 family members per MI patient. In total, we identified 11 potential disease-causing variants that co-segregate within the families, that is, 5% of patients with premature MI and positive CAD family history had FH. Eight variants were previously reported as disease-causing and three are novel (LDLR.c.811G>A p.(V271I)), PCSK9.c.610G>A (p.(D204N)) and STAP1.c.139A>G (p.(T47A))). Co-segregation analyses identified multiple additional family members carrying one of these FH variants and the clinical phenotype of either FH (n=2) or FH and premature CAD (n=15). However, exome sequencing also revealed that some variants in FH genes, which have been reported to cause FH, do not co-segregate with FH. The data reveal that a large proportion of FH patients escape the diagnosis, even when they have premature MI. Hence, systematic molecular-genetic screening for FH in such patients may reveal a substantial number of cases and thereby allow a timely LDLC-lowering in both FH/MI patients as well as their variant-carrying family members.

Improving the cost-effectiveness equation of cascade testing for familial hypercholesterolaemia

PURPOSE OF REVIEW

Many international recommendations for the management of familial hypercholesterolaemia propose the use of cascade testing using the family mutation to unambiguously identify affected relatives. In the current economic climate DNA information is often regarded as too expensive. Here, we review the literature and suggest strategies to improve cost-effectiveness of cascade testing.

RECENT FINDINGS

Advances in next-generation sequencing have both speeded up the time taken for a genetic diagnosis and reduced costs. Also, it is now clear that, in the majority of patients with a clinical diagnosis of familial hypercholesterolaemia in whom no mutation can be found, the most likely cause of their elevated LDL-cholesterol (LDL-C) is because they have inherited a greater number than average of common LDL-C raising variants in many different genes. The major cost driver for cascade testing is not DNA testing but treatment over the remaining lifetime of the identified relative. With potent statins now off-patent, the overall cost has reduced considerably, and combining these three factors, a familial hypercholesterolaemia service based around DNA-cascade testing is now less than 25% of that estimated by NICE in 2008.

SUMMARY

Although all patients with a clinical diagnosis of familial hypercholesterolaemia need to have their LDL-C lowered, cascade testing should be focused on those with the monogenic form and not the polygenic form.

Efficacy and safety of ezetimibe monotherapy in children with heterozygous familial or nonfamilial hypercholesterolemia

OBJECTIVES

To evaluate the lipid-altering efficacy and safety of ezetimibe monotherapy in young children with heterozygous familial hypercholesterolemia (HeFH) or nonfamilial hypercholesterolemia (nonFH).

STUDY DESIGN

One hundred thirty-eight children 6-10 years of age with diagnosed HeFH or clinically important nonFH (low-density lipoprotein cholesterol [LDL-C] ≥ 160 mg/dL [4.1 mmol/L]) were enrolled into a multicenter, 12-week, randomized, double-blind, placebo-controlled study. Following screening/drug washout and a 5-week single-blind placebo-run-in with diet stabilization, subjects were randomized 2:1 to daily ezetimibe 10 mg (n = 93) or placebo (n = 45) for 12 weeks. Lipid-altering efficacy and safety were assessed in all treated patients.

RESULTS

Overall, mean age was 8.3 years, 57% were girls, 80% were white, mean baseline LDL-C was 228 mg/dL (5.9 mmol/L), and 91% had HeFH. After 12 weeks, ezetimibe significantly reduced LDL-C by 27% after adjustment for placebo (P < .001) and produced significant reductions in total cholesterol (21%), nonhigh-density lipoprotein cholesterol (26%), and apolipoprotein B (20%) (P < .001 for all). LDL-C lowering response in sex, race, baseline lipids, and HeFH/nonFH subgroups was generally consistent with overall study results. Ezetimibe was well tolerated, with a safety profile similar to studies in older children, adolescents, and adults.

CONCLUSIONS

Ezetimibe monotherapy produced clinically relevant reductions in LDL-C and other key lipid variables in young children with primary HeFH or clinically important nonFH, with a favorable safety/tolerability profile.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00867165.

Coenzyme Q10 remarkably improves the bio-energetic function of rat liver mitochondria treated with statins

CoQ10 shares a biosynthetic pathway with cholesterol therefore it can be a potential target of the widely available lipid-lowering agents such as statins. Statins are the most widely prescribed cholesterol-lowering drugs with the ability to inhibit HMG-CoA (3-hydroxy-3-methylglutaryl-coenzyme A) reductase. Preclinical and clinical safety data have shown that statins do not cause serious adverse effects in humans. However, their long-term administration is associated with a variety of myopatic complaints. The aim of this study was to investigate whether CoQ10 supplementation of animals under high fat diet (HFD) treated with statins is able to bypass the mitochondrial metabolic defects or not? Animals were divided into 7 groups and fed with either regular (RD) or HFD during experiments. The first group considered as regular control and fed with a RD. Groups 2-7 including HFD control, CoQ10 (10mg/kg), simvastatin (30mg/kg), atorvastatin (30mg/kg), simvastatin+CoQ10 or atorvastatin+CoQ10 treated orally for 30 days and fed with HFD. At the end of treatments, the animals were killed and blood samples were collected for biochemical examinations. The rat liver mitochondria were isolated and several mitochondrial indices including succinate dehydrogenase activity (SDA), ATP levels, mitochondrial membrane potential (MMP) and mitochondrial permeability transition pore (MPP) were determined. We found that triglyceride (Tg), cholesterol (Chol) and low-density lipoprotein (LDL) were augmented with HFD compared to RD and treatment with statins remarkably lowered the Tg, Chol and LDL levels. Mitochondrial parameters including, SDA, ATP levels, MMP and MPP were reduced with statin treatment and improved by co-administration with CoQ10.