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

New Therapies for Primary Hyperlipidemia

Primary hyperlipidemias include a heterogeneous set of monogenic and polygenic conditions characterized by a strong family aggregation, severe forms of hypercholesterolemia and/or hypertriglyceridemia, appearance early on life, and a high risk of cardiovascular events and/or recurrent pancreatitis. In real life, a small proportion of the primary hyperlipidemia cases is recognized and treated properly. Our goal is to present an update of current and upcoming therapies for patients with primary hyperlipidemia. Recently, new lipid-lowering medications have obtained authorization from the U.S. Food and Drug Administration and the European Medicines Agency. These drugs target metabolic pathways, including (adenosine 5'-triphosphates)-citrate lyase (bempedoic acid), proprotein convertase subtilisin/kexin 9 (inclisiran), apolipoprotein CIII (volanesorsen), and angiopoietin-like 3 (volanesorsen), that have additive effects with the actions of the currently available therapies (i.e., statins, ezetimibe or fibrates). We discuss the potential clinical indications for the novel medications. To conclude, the addition of these new medications to the therapeutic options for primary hyperlipidemia patients may increase the likelihood of achieving the treatment targets. Also, it could be a safer alternative for patients with side effects for the currently available drugs.

Improving detection and management of familial hypercholesterolaemia in Australian general practice

OBJECTIVE

Familial hypercholesterolaemia (FH) is characterised by elevated low-density lipoprotein (LDL)-cholesterol and increased risk of cardiovascular disease. However, FH remains substantially underdiagnosed and undertreated. We employed a two-stage pragmatic approach to identify and manage patients with FH in primary healthcare.

METHODS

Medical records for 232 139 patients who attended 15 general practices at least once in the previous 2 years across five Australian States were first screened for potential risk of FH using an electronic tool (TARB-Ex) and confirmed by general practitioner (GP) clinical assessment based on phenotypic Dutch Lipid Clinic Network Criteria (DLCNC) score. Follow-up GP consultation and management was provided for patients with phenotypic FH.

RESULTS

A total of 1843 patients were identified by TARB-Ex as at potential risk of FH (DLCNC score ≥5). After GP medical record review, 900 of these patients (49%) were confirmed with DLCNC score ≥5 and classified as high-risk of FH. From 556 patients subsequently clinically assessed by GPs, 147 (26%) were diagnosed with phenotypic FH (DLCNC score >6). Follow-up GP consultation and management for 77 patients resulted in a significant reduction in LDL-cholesterol (-16%, p<0.01). A higher proportion of these patients attained the treatment target of 50% reduction in LDL-cholesterol (74% vs 62%, p<0.001) and absolute levels of LDL-cholesterol goals compared with baseline (26% vs 12%, p<0.05).

CONCLUSIONS

A pragmatic approach integrating electronic medical record tools and clinical GP follow-up consultation is a feasible method to identify and better manage patients with FH in the primary healthcare setting.

TRIAL REGISTRATION NUMBER

12616000630415.

Validity and reliability of an adapted questionnaire measuring knowledge, awareness and practice regarding familial hypercholesterolaemia among primary care physicians in Malaysia

BACKGROUND

Primary care physicians (PCP) play an important role in detecting Familial Hypercholesterolaemia (FH) early. However, knowledge, awareness and practice (KAP) regarding FH among Malaysian PCP are not well established, and there was no validated tool to assess their FH KAP. Thus, the aim of this study was to adapt an FH KAP questionnaire and determine its validity and reliability among Malaysian PCP.

METHODS

This cross-sectional validation study involved Malaysian PCP with ≥ 1-year work experience in the primary care settings. In Phase 1, the original 19-item FH KAP questionnaire underwent content validation and adaptation by 7 experts. The questionnaire was then converted into an online survey instrument and was face validated by 10 PCP. In Phase 2, the adapted questionnaire was disseminated through e-mail to 1500 PCP. Data were collected on their KAP, demography, qualification and work experience. The construct validity was tested using known-groups validation method. The hypothesis was PCP holding postgraduate qualification (PCP-PG-Qual) would have better FH KAP compared with PCP without postgraduate qualification (PCP-noPG-Qual). Internal consistency reliability was calculated using Kuder Richardson formula-20 (KR-20) and test-retest reliability was tested on 26 PCP using kappa statistics.

RESULTS

During content validation and adaptation, 10 items remained unchanged, 8 items were modified, 1 item was moved to demography and 7 items were added. The adapted questionnaire consisted of 25 items (11 knowledge, 5 awareness and 9 practice items). A total of 130 out of 1500 PCP (response rate: 8.7%) completed the questionnaire. The mean percentage knowledge score was found to be significantly higher in PCP-PG-Qual compared with PCP-noPG-Qual (53.5, SD ± 13.9 vs. 35.9, SD ± 11.79), t(128) = 6.90, p < 0.001. The median percentage awareness score was found to be significantly higher in PCP-PG-Qual compared with PCP-noPG-Qual (15.4, IqR ± 23.08 vs. 7.7, IqR ± 15.38), p = 0.030. The mean percentage practice score was significantly higher in PCP-PG-Qual compared with PCP-noPG-Qual (69.2, SD ± 17.62 vs. 54.4, SD ± 19.28), t(128) = 3.79, p < 0.001. KR-20 value was 0.79 (moderate reliability) and average Kappa was 0.796 (substantial agreement).

CONCLUSION

This study has proven that the 25-item adapted FH KAP questionnaire is valid and reliable. It can be used to measure and establish FH KAP among PCP in Malaysia.

Improving the detection of familial hypercholesterolaemia

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

Relationship between Lipid Phenotypes, Overweight, Lipid Lowering Drug Response and KIF6 and HMG-CoA Genotypes in a Subset of the Brisighella Heart Study Population

The existence of genetic traits might explain the susceptibility to develop hypercholesterolemia and the inter-individual differences in statin response. This study was performed to evaluate whether individuals' polymorphisms in HMG-CoA and KIF6 genes are independently associated with hypercholesterolemia, other lipid-associated traits, and statin response in unselected individuals enrolled in the Brisighella heart study (Survey 2012). A total of 1622 individuals, of which 183 under statin medication, were genotyped for a total of five polymorphisms (KIF6 rs20455, rs9471077, rs9462535; HMG-CoA rs3761740, rs3846662). The relationships between the five loci and clinical characteristics were analyzed. The principal basic parameters calculated on 12 h fasting blood included total cholesterol (TC), High Density Lipoprotein Cholesterol (HDL-C), Low-Density Lipoprotein Cholesterol (LDL-C), and triglycerides (TG). Hypercholesterolemia was defined as a TC >200 mg/dL or use of lipid-lowering medication. 965 individuals were characterized by hypercholesterolemia; these subjects were significantly older (p < 0.001), with body mass index (BMI) and waist circumference significantly higher (p < 0.001) compared to the others. HMG-CoA rs3846662 GG genotype was significantly over-represented in the hypercholesterolemic group (p = 0.030). HMG-CoA rs3846662 genotype was associated with the level of TC and LDL-C. Furthermore, in the same subset of untreated subjects, we observed a significant correlation between the KIF6 rs20455 and HDL-C. KIF6 variants were associated with a significantly lower (rs20455) or higher (rs9471077 and rs9462535) risk of obesity, in males only. No association between responsiveness to statins and the polymorphisms under investigation were observed. Our results showed associations between HMG-CoA rs3846662 and KIF6 rs20455 and lipid phenotypes, which may have an influence on dyslipidemia-related events. Moreover, this represents the first study implicating KIF6 variants with obesity in men, and point to the possible involvement of this genetic locus in the known gender-related differences in coronary artery disease.

Detection and management of familial hypercholesterolaemia in primary care in Australia: protocol for a pragmatic cluster intervention study with pre-post intervention comparisons

INTRODUCTION

Familial hypercholesterolaemia (FH), an autosomal dominant disorder of lipid metabolism, results in accelerated onset of atherosclerosis if left untreated. Lifelong treatment with diet, lifestyle modifications and statins enable a normal lifespan for most patients. Early diagnosis is critical. This protocol trials a primary care-based model of care (MoC) to improve detection and management of FH.

METHODS AND ANALYSIS

Pragmatic cluster intervention study with pre-post intervention comparisons in Australian general practices. At study baseline, current FH detection practice is assessed. Medical records over 2 years are electronically scanned using a data extraction tool (TARB-Ex) to identify patients at increased risk. High-risk patients are clinically reviewed to provide definitive, phenotypic diagnosis using Dutch Lipid Clinic Network Criteria. Once an index family member with FH is identified, the primary care team undertake cascade testing of first-degree relatives to identify other patients with FH. Management guidance based on disease complexity is provided to the primary care team. Study follow-up to 12 months with TARB-Ex rerun to identify total number of new FH cases diagnosed over study period (via TARB-Ex, cascade testing and new cases presenting). At study conclusion, patient and clinical staff perceptions of enablers/barriers and suggested improvements to the approach will be examined. Resources at each stage will be traced to determine the economic implications of implementing the MoC and costed from health system perspective. Primary outcomes: increase in number of index cases clinically identified; reduction in low-density lipoprotein cholesterol of treated cases.

SECONDARY OUTCOMES

increase in the number of family cases detected/contacted; cost implications of the MoC.

ETHICS AND DISSEMINATION

Study approval by The University of Notre Dame Australia Human Research Ethics Committee Protocol ID: 0 16 067F. Registration: Australian New Zealand Clinical Trials Registry ID: 12616000630415. Information will be disseminated via research seminars, conference presentations, journal articles, media releases and community forums.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry ID 12616000630415; Pre-results.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

The use of targeted exome sequencing in genetic diagnosis of young patients with severe hypercholesterolemia

Familial hypercholesterolemia (FH) is an autosomal dominant disorder. Although genetic testing is an important tool for detecting FH-causing mutations in patients, diagnostic methods for young patients with severe hypercholesterolemia are understudied. This study compares the target exome sequencing (TES) technique with the DNA resequencing array technique on young patients with severe hypercholesterolemia. A total of 20 unrelated patients (mean age 14.8 years) with total cholesterol > 10 mmol/L were included. 12 patient samples were processed by DNA resequencing array, 14 patient samples were processed by TES, and 6 patient samples were processed by both methods. Functional characterization of novel mutations was performed by flow cytometry. The mutation detection rate (MDR) of DNA resequencing array was 75%, while the MDR of TES was 100%. A total of 27 different mutations in the LDLR were identified, including 3 novel mutations and 8 mutations with previously unknown pathogenicity. Functional characterization of c.673delA, c.1363delC, p.Leu575Phe and p.Leu582Phe variants found that all of them are pathogenic. Additionally, 7 patients were diagnosed with Heterozygous FH (HeFH) in which lipid levels were significantly higher than common HeFH patients. This data indicates that TES is a very efficient tool for genetic diagnosis in young patients with severe hypercholesterolemia.

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.