Developing and applying clinically useful approaches to identify individuals with familial hypercholesterolemia in the UK

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.

Familial Hypercholesterolaemia in 2020: A Leading Tier 1 Genomic Application

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

Familial Hypercholesterolemia: Cascade Screening in Children and Relatives of the Affected

OBJECTIVE

Familial Hypercholesterolemia (FH) is an inherited disorder of lipid metabolism characterized by very high low density lipoprotein (LDL) cholesterol since birth, resulting in premature atherosclerosis and coronary artery disease (CAD). Cascade screening of children and family members of proven FH individuals can identify more subjects who have high LDL cholesterol or the family mutation and appropriate intervention can reduce their risk of atherosclerosis and prevent its complications.

METHODS

Cascade screening by molecular testing, was carried out in 133 family members, comprising 24 children, of 31 probands with FH having a pathogenic mutation in LDLR/ApoB gene. Lipid profiles were obtained in 44 family members including 11 children.

RESULTS

Of 133 family members tested, 88 (66.1%) were identified to carry the family mutation. Twelve of these were children below 18 y of age and 76 were adults. CAD was present in 15 (11.2%) family members and 63(47.4%) family members, including nine children, were already on Lipid Lowering Therapy.

CONCLUSIONS

Cascade screening led to identification of 88 new cases, with a pathogenic mutation, who were at a very high risk of developing premature CAD. The authors identified 12 children with family specific mutation, out of which 9 were initiated on low dose statin therapy. Four homozygous children were treated with high dose statins because of substantially increased risk of CAD. Cascade screening, therefore, proved to be a successful initiative towards primary prevention of CAD in India.

Review of the cost effectiveness of pharmacogenetic-guided treatment of hypercholesterolaemia

Hypercholesterolaemia is a highly prevalent condition that has major health and cost implications for society. Pharmacotherapy is an important and effective treatment modality for hypercholesterolaemia, with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors ('statins') the most commonly used class of drugs. Over the past decade, there has been intensive research to identify pharmacogenetic markers to guide treatment of hypercholesterolaemia. This study aimed to review the evidence of incremental cost, effect and cost effectiveness of pharmacogenetic-guided treatment of hypercholesterolaemia. Three cost-effectiveness analyses (CEAs) were identified that studied the value of screening for genotypes of angiotensin I converting enzyme (ACE), cholesteryl ester transfer protein (CETP), and kinesin family member 6 (KIF6) prior to initiating statin therapy. For all three CEAs, a major limitation identified was the reproducibility of the evidence supporting the clinical effect of screening for the pharmacogenetic marker. Associated issues included the uncertain value of pharmacogenetic markers over or in addition to existing approaches for monitoring lipid levels, and the lack of evidence to assess the effectiveness of alternative therapeutic options for individuals identified as poor responders to statin therapy. Finally, the economic context of the market for diagnostic tests (is it competitive or is there market power?) and the practicality of large-scale screening programmes to inform prescribing in a complex and varied market may limit the generalizability of the results of the specific CEAs to policy outcomes. The genotype of solute carrier organic anion transporter family member 1B1 (SLCO1B1) has recently been associated with increased risk of muscle toxicity with statin therapy and the review identified that exploration of cost effectiveness of this pharmacogenetic marker is likely warranted.