Familial hypercholesterolemias: prevalence, genetics, diagnosis and screening recommendations from the National Lipid Association Expert Panel on Familial Hypercholesterolemia

Rapid identification of familial hypercholesterolemia from electronic health records: The SEARCH study

BACKGROUND

Little is known about prevalence, awareness, and control of familial hypercholesterolemia (FH) in the United States.

OBJECTIVE

To address these knowledge gaps, we developed an ePhenotyping algorithm for rapid identification of FH in electronic health records (EHRs) and deployed it in the Screening Employees And Residents in the Community for Hypercholesterolemia (SEARCH) study.

METHODS

We queried a database of 131,000 individuals seen between 1993 and 2014 in primary care practice to identify 5992 (mean age 52 ± 13 years, 42% men) patients with low-density lipoprotein cholesterol (LDL-C) ≥190 mg/dL, triglycerides <400 mg/dL and without secondary causes of hyperlipidemia.

RESULTS

Our EHR-based algorithm ascertained the Dutch Lipid Clinic Network criteria for FH using structured data sets and natural language processing for family history and presence of FH stigmata on physical examination. Blinded expert review revealed positive and negative predictive values for the SEARCH algorithm at 94% and 97%, respectively. The algorithm identified 32 definite and 391 probable cases with an overall FH prevalence of 0.32% (1:310). Only 55% of the FH cases had a diagnosis code relevant to FH. Mean LDL-C at the time of FH ascertainment was 237 mg/dL; at follow-up, 70% (298 of 423) of patients were on lipid-lowering treatment with 80% achieving an LDL-C ≤100 mg/dL. Of treated FH patients with premature CHD, only 22% (48 of 221) achieved an LDL-C ≤70 mg/dL.

CONCLUSIONS

In a primary care setting, we found the prevalence of FH to be 1:310 with low awareness and control. Further studies are needed to assess whether automated detection of FH in EHR improves patient outcomes.

Identifying familial hypercholesterolemia in acute coronary syndrome

PURPOSE OF REVIEW

Familial hypercholesterolemia is a frequent genetic disorder characterized by elevated LDL-cholestrol and premature coronary heart disease. Familial hypercholesterolemia remains largely underdiagnosed in the general population and for many patients the initial clinical manifestation is acute coronary syndromes (ACS). Furthermore, many missed diagnosis of familial hypercholesterolemia can also occur during hospitalization for ACS. In this review, we aim to discuss the identification and prognosis of familial hypercholesterolemia after hospitalization for ACS.

RECENT FINDINGS

The prevalence of familial hypercholesterolemia was about 10 times higher among patients hospitalized for ACS compared with the general population. Although 70% of patients with familial hypercholesterolemia were discharged with high-intensity statins, and 65% attended cardiac rehabilitation, less than 5% reached the recommended LDL-cholesterol target less than 1.8 mmol/l 1 year after ACS. Furthermore, patients with familial hypercholesterolemia and ACS were at high-risk of recurrence of cardiovascular events after discharge.

SUMMARY

A systematic screening strategy to identify patients with familial hypercholesterolemia at the time ACS is required to maximize secondary prevention and improve lipid management. It is expected that a substantial number of familial hypercholesterolemia patients would benefit from more effective lipid-lowering drugs after ACS, in addition to statins.

Challenges in the Diagnosis and Treatment of Homozygous Familial Hypercholesterolemia

Homozygous familial hypercholesterolemia (HoFH) is a rare, genetic disorder characterized by an absence or impairment of low-density lipoprotein receptor (LDLR) function resulting in significantly elevated low-density lipoprotein cholesterol (LDL-C) levels. The cholesterol exposure burden beginning in utero greatly increases the risk for atherosclerotic cardiovascular disease (ASCVD) and premature death. The genetic heterogeneity of HoFH results in a wide range of LDL-C levels among both untreated and treated patients. Diagnosis of HoFH should, therefore, be based on a comprehensive evaluation of clinical criteria and not exclusively LDL-C levels. As treatment goals, the European Atherosclerosis Society and International FH Foundation suggest target LDL-C levels of <100 mg/dL (<2.5 mmol/L) in adults or <70 mg/dL (<1.8 mmol/L) in adults with clinical coronary artery disease or diabetes. The National Lipid Association (NLA) recommends that LDL-C levels be reduced to <100 mg/dL (<2.5 mmol/L) or by at least ≥50 % from pretreatment levels. Conventional therapy combinations that lower atherogenic lipoproteins levels in the blood, such as statins, ezetimibe, bile acid sequestrants and niacin, as well as lipoprotein apheresis, are usually unable to reduce LDL-C levels to recommended targets. Two recently approved agents that reduce lipoprotein synthesis and secretion by the liver are lomitapide, a microsomal triglyceride transfer protein inhibitor, and mipomersen, an apolipoprotein B antisense oligonucleotide. The newly approved inhibitor of proprotein convertase subtilisin/kexin type 9 (PCSK9), evolocumab, also shows promise for the management of FH. Because of the extremely high risk for ASCVD, HoFH patients should be identified early.

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.

Long-Term Risk of Atherosclerotic Cardiovascular Disease in US Adults With the Familial Hypercholesterolemia Phenotype

BACKGROUND

Heterozygous familial hypercholesterolemia (FH) affects up to 1 in 200 individuals in the United States, but atherosclerotic cardiovascular disease (ASCVD) outcomes of FH in the general US population have not been described. We therefore sought to evaluate long-term coronary heart disease (CHD) and total ASCVD risks in US adults with an FH phenotype.

METHODS

Using individual pooled data from 6 large US epidemiological cohorts, we stratified participants by low-density lipoprotein cholesterol level at index ages from 20 to 79 years. For the primary analysis, low-density lipoprotein cholesterol levels ≥190 and <130 mg/dL defined the FH phenotype and referent, respectively. Sensitivity analyses evaluated the effects of varying the FH phenotype definition. We used Cox regression models to assess covariate-adjusted associations of the FH phenotype with 30-year hazards for CHD (CHD death or nonfatal myocardial infarction) and total ASCVD (CHD or stroke).

RESULTS

We included 68 565 baseline person-examinations; 3850 (5.6%) had the FH phenotype by the primary definition. Follow-up across index ages ranged from 78 985 to 308 378 person-years. After covariate adjustment, the FH phenotype was associated with substantially elevated 30-year CHD risk, with hazard ratios up to 5.0 (95% confidence interval, 1.1-21.7). Across index ages, CHD risk was accelerated in those with the FH phenotype by 10 to 20 years in men and 20 to 30 years in women. Similar patterns of results were found for total ASCVD risk, with hazard ratios up to 4.1 (95% confidence interval, 1.2-13.4). Alternative FH phenotype definitions incorporating family history, more stringent age-based low-density lipoprotein cholesterol thresholds, or alternative lipid fractions decreased the FH phenotype prevalence to as low as 0.2% to 0.4% without materially affecting CHD risk estimates (hazard ratios up to 8.0; 95% confidence interval, 1.0-61.6).

CONCLUSIONS

In the general US population, the long-term ASCVD burden related to phenotypic FH, defined by low-density lipoprotein cholesterol ≥190 mg/dL, is likely substantial. Our finding of CHD risk acceleration may aid efforts in risk communication.

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.

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.

Long-term mipomersen treatment is associated with a reduction in cardiovascular events in patients with familial hypercholesterolemia

BACKGROUND

Familial hypercholesterolemia (FH) is characterized by severely elevated LDL-cholesterol and up to a 20-fold increase in premature cardiovascular disease (CVD).

OBJECTIVE

Mipomersen has been shown to lower the levels of these atherogenic lipoproteins, but whether it lowers major adverse cardiac events (MACEs) has not been addressed.

METHODS

This post hoc analysis of prospectively collected data of three randomized trials and an open-label extension phase included patients that were exposed to ≥12 months of mipomersen. MACE rates that occurred during 24 months before randomization in the mipomersen group were compared to MACE rates after initiation of mipomersen. Data from the trials included in this report are registered in Clinicaltrials.gov (NCT00607373, NCT00706849, NCT00794664, NCT00694109). The occurrence of MACE events, defined as cardiovascular death, nonfatal acute myocardial infarction, hospitalization for unstable angina, coronary revascularization and nonfatal ischemic stroke, was obtained from medical history data pre-treatment and adjudicated by an independent adjudication committee for events occurring post-treatment with mipomersen.

RESULTS

MACEs were identified in 61.5% of patients (64 patients with 146 events [39 myocardial infarctions, 99 coronary revascularizations, 5 unstable angina episodes, 3 ischemic strokes]) during 24 months before mipomersen treatment, and in 9.6% of patients (10 patients with 13 events [1 cardiovascular death, 2 myocardial infarctions, 6 coronary interventions, 4 unstable angina episodes]) during a mean of 24.4 months after initiation of mipomersen (MACE rate 25.7 of 1000 patient-months vs 3.9 of 1000 patient-months, OR = 0.053 [95% CI, 0.016-0.168], P < .0001 by the exact McNemar test). The reduction in MACE coincided with a mean absolute reduction in LDL-C of 70 mg/dL (-28%) and of non-HDL cholesterol of 74 mg/dL (-26%) as well as reduction in Lp(a) of 11 mg/dL (-17%).

CONCLUSION

Long-term mipomersen treatment not only lowers levels of atherogenic lipoproteins but may also lead to a reduction in cardiovascular events in FH patients.

Treatment Gaps in Adults With Heterozygous Familial Hypercholesterolemia in the United States: Data From the CASCADE-FH Registry

BACKGROUND

Cardiovascular disease burden and treatment patterns among patients with familial hypercholesterolemia (FH) in the United States remain poorly described. In 2013, the FH Foundation launched the Cascade Screening for Awareness and Detection (CASCADE) of FH Registry to address this knowledge gap.

METHODS AND RESULTS

We conducted a cross-sectional analysis of 1295 adults with heterozygous FH enrolled in the CASCADE-FH Registry from 11 US lipid clinics. Median age at initiation of lipid-lowering therapy was 39 years, and median age at FH diagnosis was 47 years. Prevalent coronary heart disease was reported in 36% of patients, and 61% exhibited 1 or more modifiable risk factors. Median untreated low-density lipoprotein cholesterol (LDL-C) was 239 mg/dL. At enrollment, median LDL-C was 141 mg/dL; 42% of patients were taking high-intensity statin therapy and 45% received >1 LDL-lowering medication. Among FH patients receiving LDL-lowering medication(s), 25% achieved an LDL-C <100 mg/dL and 41% achieved a ≥50% LDL-C reduction. Factors associated with prevalent coronary heart disease included diabetes mellitus (adjusted odds ratio 1.74; 95% confidence interval 1.08-2.82) and hypertension (2.48; 1.92-3.21). Factors associated with a ≥50% LDL-C reduction from untreated levels included high-intensity statin use (7.33; 1.86-28.86) and use of >1 LDL-lowering medication (1.80; 1.34-2.41).

CONCLUSIONS

FH patients in the CASCADE-FH Registry are diagnosed late in life and often do not achieve adequate LDL-C lowering, despite a high prevalence of coronary heart disease and risk factors. These findings highlight the need for earlier diagnosis of FH and initiation of lipid-lowering therapy, more consistent use of guideline-recommended LDL-lowering therapy, and comprehensive management of traditional coronary heart disease risk factors.

Communicating risk with relatives in a familial hypercholesterolemia cascade screening program: a summary of the evidence

BACKGROUND

Familial hypercholesterolemia (FH) is the most common inherited, potentially deadly disease, affecting an estimated 600 000 people in the United States. When FH is undiagnosed and untreated, it is linked with early coronary heart disease in more than 50% of men by age 50 years and 30% of women by age 60 years. Cascade screening is the most cost effective method available to identify family members with this disease; however, cascade screening guidelines do not specify best methods to use when contacting relatives. Therefore, I conducted an exhaustive search of the literature to find the most successful communication methods used in contact tracing and cascade screening.

PURPOSE

The purpose of this summary of the evidence was to identify the communication method with greatest impact in having at-risk populations present to a provider for disease screening. These findings will inform clinicians of the most successful methods to implement when cascade screening relatives of known FH patients.

CONCLUSIONS

Most studies support direct contact of relatives via letter, mailed from the provider. Provider-initiated communication more often resulted in relatives being tested when compared with other methods of communication.

CLINICAL IMPLICATIONS

On the basis of the literature, family members of current FH patients will be more likely to present to a provider for cascade screening if they receive written communication from the provider.

Phenotype diversity among patients with homozygous familial hypercholesterolemia: A cohort study

AIMS

Homozygous familial hypercholesterolaemia (HoFH) is a rare disorder usually caused by mutations in both alleles of the low-density lipoprotein receptor gene (LDLR). Premature death, often before the age of 20 years, was a common fate for patients with HoFH prior to the introduction of statins in 1990 and the use of lipoprotein apheresis. Consequently, HoFH has been widely considered a condition exclusive to a population comprising very young patients with extremely high LDL cholesterol (LDL-C) levels. However, recent epidemiologic and genetic studies have shown that the HoFH patient population is far more diverse in terms of age, LDL-C levels, and genetic aetiology than previously realised. We set out to investigate the clinical characteristics regarding age and LDL-C ranges of patients with HoFH.

METHODS AND RESULTS

We analysed the data from 3 recent international studies comprising a total of 167 HoFH patients. The age of the patients ranged from 1 to 75 years, and a large proportion of the patients, both treated and untreated, exhibited LDL-C levels well below the recommended clinical diagnostic threshold for HoFH. LDL-C levels ranged from 4.4 mmol/L to 27.2 mmol/L (170-1052 mg/dL) for untreated patients, and from 2.6 mmol/L to 20.3 mmol/L (101-785 mg/dL) for treated patients. When patients were stratified according to LDLR functionality, a similarly wide range of age and LDL-C values was observed regardless of LDLR mutation status.

CONCLUSION

These results demonstrate that HoFH is not restricted to very young patients or those with extremely high LDL-C levels.

PCSK9 inhibitors and their role in high-risk patients in reducing LDL cholesterol levels: evolocumab

Patients with familial hypercholesterolemia or statin intolerance are especially challenging to manage since LDL cholesterol levels often remain considerably elevated despite clinicians’ best efforts. With statins regarded as first-line pharmacologic therapy by the current American College of Cardiology/American Heart Association guidelines to reduce LDL cholesterol and cardiovascular risk, there is now a critical need to determine when other agents will play a role beyond maximally tolerated statin therapy and lifestyle changes. In this review, we take a closer look at evolocumab (Repatha®), one of the new injectable human monoclonal antibodies to PCSK9 and its efficacy and safety properties from the results of various trials.

Genetic Testing in Hyperlipidemia

Hereditary dyslipidemias are often underdiagnosed and undertreated, yet with significant health implications, most importantly causing preventable premature cardiovascular diseases. The commonly used clinical criteria to diagnose hereditary lipid disorders are specific but are not very sensitive. Genetic testing may be of value in making accurate diagnosis and improving cascade screening of family members, and potentially, in risk assessment and choice of therapy. This review focuses on using genetic testing in the clinical setting for lipid disorders, particularly familial hypercholesterolemia.

Familial Hypercholesterolemia

Familial hypercholesterolemia is a common, inherited disorder of cholesterol metabolism that leads to early cardiovascular morbidity and mortality. It is underdiagnosed and undertreated. Statins, ezetimibe, bile acid sequestrants, niacin, lomitapide, mipomersen, and low-density lipoprotein (LDL) apheresis are treatments that can lower LDL cholesterol levels. Early treatment can lead to substantial reduction of cardiovascular events and death in patients with familial hypercholesterolemia. It is important to increase awareness of this disorder in physicians and patients to reduce the burden of this disorder.

Familial hypercholesterolemia

Familial hypercholesterolemia is a common, inherited disorder of cholesterol metabolism that leads to early cardiovascular morbidity and mortality. It is underdiagnosed and undertreated. Statins, ezetimibe, bile acid sequestrants, niacin, lomitapide, mipomersen, and low-density lipoprotein (LDL) apheresis are treatments that can lower LDL cholesterol levels. Early treatment can lead to substantial reduction of cardiovascular events and death in patients with familial hypercholesterolemia. It is important to increase awareness of this disorder in physicians and patients to reduce the burden of this disorder.

Genetics of familial hypercholesterolemia

Familial hypercholesterolemia (FH) is a genetic disorder characterized by elevated low-density lipoprotein (LDL) cholesterol and premature cardiovascular disease, with a prevalence of approximately 1 in 200-500 for heterozygotes in North America and Europe. Monogenic FH is largely attributed to mutations in the LDLR, APOB, and PCSK9 genes. Differential diagnosis is critical to distinguish FH from conditions with phenotypically similar presentations to ensure appropriate therapeutic management and genetic counseling. Accurate diagnosis requires careful phenotyping based on clinical and biochemical presentation, validated by genetic testing. Recent investigations to discover additional genetic loci associated with extreme hypercholesterolemia using known FH families and population studies have met with limited success. Here, we provide a brief overview of the genetic determinants, differential diagnosis, genetic testing, and counseling of FH genetics.

Functional characterization of mutant genes associated with autosomal dominant familial hypercholesterolemia: integration and evolution of genetic diagnosis

AIMS

Familial Hypercholesterolemia (FH) is one of the most frequent dyslipidemias, the autosomal dominant form of which is primarily caused by mutations in the LDL receptor (LDLR), apolipoprotein B (APOB), and proprotein convertase subtilisin/kexin type 9 (PCSK9) genes, although in around 20% of patients the genetic cause remains unidentified. Genetic testing has notably improved the identification of patients suffering from FH, the most frequent cause of which is the presence of mutations in the LDLR gene. Although more than 1200 different mutations have been identified in this gene, about 80% are recognized to be pathogenic. We aim to overview the current methods used to perform the functional characterization of mutations causing FH and to highlight the conditions requiring a functional characterization of the variant in order to obtain a diagnostic report.

DATA SYNTHESIS

In the current review, we summarize the different types of functional assays - including their advantages and disadvantages - performed to characterize mutations in the LDLR, APOB and PCSK9 genes helping to better define their pathogenic role. We describe the evaluation of splicing alterations and two major procedures for functional characterization: 1. ex vivo methods, using cells from FH patients; 2. in vitro methods using cell lines.

CONCLUSIONS

Functional characterization of the LDLR, APOB and PCSK9 mutant genes associated with FH can be considered a necessary integration of its genetic diagnosis.

Type of LDLR mutation and the pharmacogenetics of familial hypercholesterolemia treatment

Familial hypercholesterolemia (FH) is an autosomal dominant disease mainly caused by mutations in the low-density lipoprotein receptor (LDLR) gene. FH patients present a wide variability regarding response to drugs and they are usually undertreated. Here, we review studies that evaluated the association between the type of LDLR mutation and the response to lipid-lowering therapy. The main findings were that patients with a null LDLR mutation had: higher baseline LDL-C, higher LDL-C after drug therapy, lower proportion of patients within the LDL-C target value and higher frequencies of CVD. Thus, we conclude that FH patients harboring a null mutation have a trend to an increased risk, even if diagnosis is early established and lipid-lowering treatment instituted. It is suggested that these individuals may benefit from the use of newly approved lipid-lowering agents.

Temporal trends in lipid screening and therapy among youth from 2002 to 2012

BACKGROUND

Pediatric lipid management recommendations have evolved from selective screening to universal screening to identify and target therapy for genetic dyslipidemias. Data on the success of the selective screening guidelines for lipid testing, dyslipidemia detection, and lipid management are conflicting.

OBJECTIVE

To determine temporal trends in lipid testing, dyslipidemia categories and pharmacotherapy in a cohort of 653,642 individual youth aged 2 to 20 years from 2002 to 2012.

METHODS

Summary data on lipid test results, lipid-lowering medicine (LLM) dispensings, and International Classification of Diseases, Ninth Revision diagnoses were compiled from the virtual data warehouses of 5 sites in the Cardiovascular Research Network. Temporal trends were determined using linear regression.

RESULTS

Among the average 255,160 ± 25,506 children enrolled each year, lipid testing declined from 16% in 2002 to 11% in 2012 (P < .001 for trend). Among the entire population, the proportion newly detected each year with low-density lipoprotein cholesterol >190 mg/dL, a value commonly used to define familial hypercholesterolemia, increased over time from 0.03% to 0.06% (P = .03 for trend). There was no significant change over time in the proportion of the yearly population initiated on LLM or statins specifically (0.045 ± 0.009%, P = .59 [LLM] and 0.028 ± 0.006%, P = .25 [statin]).

CONCLUSIONS

Although lipid testing declined during 2002 to 2012, the detection of familial hypercholesterolemia-level low-density lipoprotein cholesterol increased. Despite this increased detection, pharmacotherapy did not increase over time. These findings highlight the need to enhance lipid screening and management strategies in high-risk youth.

Cascade Screening in Familial Hypercholesterolemia: Advancing Forward

Familial hypercholesterolemia is a genetic disorder associated with elevated LDL-cholesterol and high lifetime cardiovascular risk. Both clinical and molecular cascade screening programs have been implemented to increase early definition and treatment. In this systematic review, we discuss the main issues found in 65 different articles related to cascade screening and familial hypercholesterolemia, covering a range of topics including different types/strategies, considerations both positive and negative regarding cascade screening in general and associated with the different strategies, cost and coverage consideration, direct and indirect contact with patients, public policy around life insurance and doctor-patient confidentiality, the "right to know," and public health concerns regarding familial hypercholesterolemia.

Familial hypercholesterolemia presenting with multiple nodules of the hands and elbow

Familial hypercholesterolemia (FH) is a common but commonly missed diagnosis. Tendon xanthomas are a physical sign strongly suggestive of FH. Physicians must identify tendon xanthomas, apply validated clinical scoring such as the Dutch Lipid Clinic Network criteria and offer cascade screening. This approach will increase recognition of FH.

Development and rescue of human familial hypercholesterolaemia in a xenograft mouse model

Diseases of lipid metabolism are a major cause of human morbidity, but no animal model entirely recapitulates human lipoprotein metabolism. Here we develop a xenograft mouse model using hepatocytes from a patient with familial hypercholesterolaemia caused by loss-of-function mutations in the low-density lipoprotein receptor (LDLR). Like familial hypercholesterolaemia patients, our familial hypercholesterolaemia liver chimeric mice develop hypercholesterolaemia and a 'humanized‘ serum profile, including expression of the emerging drug targets cholesteryl ester transfer protein and apolipoprotein (a), for which no genes exist in mice. We go on to replace the missing LDLR in familial hypercholesterolaemia liver chimeric mice using an adeno-associated virus 9-based gene therapy and restore normal lipoprotein profiles after administration of a single dose. Our study marks the first time a human metabolic disease is induced in an experimental animal model by human hepatocyte transplantation and treated by gene therapy. Such xenograft platforms offer the ability to validate human experimental therapies and may foster their rapid translation into the clinic.

Familial hypercholesterolemia (FH) is a congenital disease associated with high plasma cholesterol levels. Here, the authors recapitulate FH in chimeric mice, in which livers are repopulated with hepatocytes from an FH patient, and successfully correct the disease using adenovirus-mediated gene therapy.

Increased Mean Platelet Volume in Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is a genetic disorder of lipoprotein metabolism and increases the risk of premature cardiovascular diseases. In patients with FH, platelet function may be activated; however, the extent of this activation and its etiology are unclear. We aimed to evaluate the mean platelet volume (MPV), a marker of platelet activation, in patients with FH. The study group consisted of 164 patients with FH and 160 control patients. Controls were matched for age, gender, hypertension, and smoking. The MPV was significantly higher in patients with FH than in controls (9.2 ± 0.4 vs 7.9 ± 0.6 fL, respectively; P < .001). Platelet count was significantly lower among patients with FH when compared to control patients (259 ± 51 vs 272 ± 56 × 103/L, respectively; P = .03). In linear regression analysis, MPV was independently associated only with total cholesterol (β = .6, 95% confidence interval: 0.004-0.008, P < .001). We have shown that MPV was increased in patients with FH and that it was independently associated with total cholesterol level.

National lipid association recommendations for patient-centered management of dyslipidemia: part 1--full report

The leadership of the National Lipid Association convened an Expert Panel to develop a consensus set of recommendations for patient-centered management of dyslipidemia in clinical medicine. An Executive Summary of those recommendations was previously published. This document provides support for the recommendations outlined in the Executive Summary. The major conclusions include (1) an elevated level of cholesterol carried by circulating apolipoprotein B-containing lipoproteins (non-high-density lipoprotein cholesterol and low-density lipoprotein cholesterol [LDL-C], termed atherogenic cholesterol) is a root cause of atherosclerosis, the key underlying process contributing to most clinical atherosclerotic cardiovascular disease (ASCVD) events; (2) reducing elevated levels of atherogenic cholesterol will lower ASCVD risk in proportion to the extent that atherogenic cholesterol is reduced. This benefit is presumed to result from atherogenic cholesterol lowering through multiple modalities, including lifestyle and drug therapies; (3) the intensity of risk-reduction therapy should generally be adjusted to the patient's absolute risk for an ASCVD event; (4) atherosclerosis is a process that often begins early in life and progresses for decades before resulting a clinical ASCVD event. Therefore, both intermediate-term and long-term or lifetime risk should be considered when assessing the potential benefits and hazards of risk-reduction therapies; (5) for patients in whom lipid-lowering drug therapy is indicated, statin treatment is the primary modality for reducing ASCVD risk; (6) nonlipid ASCVD risk factors should also be managed appropriately, particularly high blood pressure, cigarette smoking, and diabetes mellitus; and (7) the measurement and monitoring of atherogenic cholesterol levels remain an important part of a comprehensive ASCVD prevention strategy.

Update of Clinical Trials of Anti-PCSK9 Antibodies

Hyperlipidemia is a predominant risk factor for cardiovascular disease (CVD). Statins have been successfully used to treat patients with dyslipidemia and decrease the events of CVD in addition to application of various other non-statin-lowering cholesterol agents, such as ezetimibe and niacin. However, there are still residual risks in patients with atherosclerotic CVD. Recently, proprotein convertase subtilisin/kexin type 9 (PCSK9), which was first identified in 2003, has been suggested to play an important role in the metabolism of low-density lipoprotein cholesterol (LDL-C). PCSK9 degrades the LDL-receptor, which may be pharmacologically targeted to improve the lipoprotein profile and future cardiovascular outcomes in patients with dyslipidemia. Several approaches to inhibiting PCSK9 activity have been theoretically proposed. Among them, monoclonal antibodies have been considered as the most promising strategy because of their large effect on lowering lipids as monotherapy and in combination with statins or ezetimibe. In this review, we mainly focus on the current status of monoclonal antibodies of PCSK9 and clinical trial results for an update on clinical application of monoclonal antibodies of PCSK9. The particular effects of monoclonal antibodies of PCSK9 on lipid profiles are also discussed.

Next generation sequencing to identify novel genetic variants causative of autosomal dominant familial hypercholesterolemia associated with increased risk of coronary heart disease

Familial hypercholesterolemia (FH) is an autosomal dominant inherited disease characterized by elevated plasma low-density lipoprotein cholesterol (LDL-C). It is an autosomal dominant disease, caused by variants in Ldlr, ApoB or Pcsk9, which results in high levels of LDL-cholesterol (LDL-C) leading to early coronary heart disease. Sequencing whole genome for screening variants for FH are not suitable due to high cost. Hence, in this study we performed targeted customized sequencing of FH 12 genes (Ldlr, ApoB, Pcsk9, Abca1, Apoa2, Apoc3, Apon2, Arh, Ldlrap1, Apoc2, ApoE, and Lpl) that have been implicated in the homozygous phenotype of a proband pedigree to identify candidate variants by NGS Ion torrent PGM. Only three genes (Ldlr, ApoB, and Pcsk9) were found to be highly associated with FH based on the variant rate. The results showed that seven deleterious variants in Ldlr, ApoB, and Pcsk9 genes were pathological and were clinically significant based on predictions identified by SIFT and PolyPhen. Targeted customized sequencing is an efficient technique for screening variants among targeted FH genes. Final validation of seven deleterious variants conducted by capillary resulted to only one novel variant in Ldlr gene that was found in exon 14 (c.2026delG, p. Gly676fs). The variant found in Ldlr gene was a novel heterozygous variant derived from a male in the proband.

The promise of proprotein convertase subtilisin/kexin 9 inhibitors for the treatment of familial hypercholesterolemia

Familial hypercholesterolemia comprises a constellation of genetic disorders resulting in very high cholesterol levels since childhood. If untreated, it is associated with accelerated atherosclerosis and premature cardiovascular disease. It has been shown that if aggressive cholesterol lowering is achieved in familial hypercholesterolemia, the incidence of cardiovascular disease can be lowered. However, currently approved pharmacological therapies are not able to lower cholesterol to optimal levels in a large number of these patients. Proprotein convertase subtilisin/kexin 9 inhibitors are a new class of cholesterol-lowering medications that can significantly reduce cholesterol levels in these patients especially those with at least some functioning low-density lipoprotein receptors. In this article, we will briefly review familial hypercholesterolemia and the role of proprotein convertase subtilisin/kexin 9 inhibitors in this condition.

Reducing the burden of disease and death from familial hypercholesterolemia: a call to action

Familial hypercholesterolemia (FH) is a genetic disease characterized by substantial elevations of low-density lipoprotein cholesterol, unrelated to diet or lifestyle. Untreated FH patients have 20 times the risk of developing coronary artery disease, compared with the general population. Estimates indicate that as many as 1 in 500 people of all ethnicities and 1 in 250 people of Northern European descent may have FH; nevertheless, the condition remains largely undiagnosed. In the United States alone, perhaps as little as 1% of FH patients have been diagnosed. Consequently, there are potentially millions of children and adults worldwide who are unaware that they have a life-threatening condition. In countries like the Netherlands, the United Kingdom, and Spain, cascade screening programs have led to dramatic improvements in FH case identification. Given that there are currently no systematic approaches in the United States to identify FH patients or affected relatives, the patient-centric nonprofit FH Foundation convened a national FH Summit in 2013, where participants issued a "call to action" to health care providers, professional organizations, public health programs, patient advocacy groups, and FH experts, in order to bring greater attention to this potentially deadly, but (with proper diagnosis) eminently treatable, condition.

Usefulness of lipid apheresis in the treatment of familial hypercholesterolemia

Lipid apheresis is used to treat patients with severe hyperlipidemia by reducing low-density lipoprotein cholesterol (LDL-C). This study examines the effect of apheresis on the lipid panel and cardiac event rates before and after apheresis. An electronic health record screen of ambulatory patients identified 11 active patients undergoing lipid apheresis with 10/11 carrying a diagnosis of FH. Baseline demographics, pre- and postapheresis lipid levels, highest recorded LDL-C, cardiac events, current medications, and first apheresis treatment were recorded. Patients completed a questionnaire and self-reported risk factors and interest in alternative treatment. There were significant reductions in mean total cholesterol (−58.4%), LDL-C (−71.9%), triglycerides (−51%), high-density lipoprotein (HDL) cholesterol (−9.3%), and non-HDL (−68.2%) values. Thirty-four cardiac events were documented in 8 patients before apheresis, compared with 9 events in 5 patients after apheresis. Our survey showed a high prevalence of statin intolerance (64%), with the majority (90%) of participants indicating an interest in alternative treatment options. Our results have shown that lipid apheresis primary effect is a marked reduction in LDL-C cholesterol levels and may reduce the recurrence of cardiac events. Apheresis should be compared to the newer alternative treatment modalities in a randomized fashion due to patient interest in alternative options.