Guidelines for the Diagnosis and Management of Familial Hypercholesterolaemia

Screening for familial hypercholesterolaemia

Familial hypercholesterolaemia (FH) is an autosomal dominant disorder characterised by increased plasma concentrations of low density lipoprotein (LDL) cholesterol leading to atherosclerosis and premature coronary heart disease (CHD) and death. The clinical diagnosis of FH is based on a personal and family history, physical examination findings and LDL-cholesterol concentrations. FH is primarily caused by mutations in the LDL-receptor gene (LDLR), and less frequently by mutations in genes for APOB and the more recently identified PCSK9. Lifestyle modification and pharmacotherapy can delay or prevent the onset of CHD in FH. It is estimated that only 20% of cases have been diagnosed in Australia and that the majority are inadequately treated. Screening options for FH include population screening (of children or adults), targeted screening of patients with premature CHD and their relatives, or opportunistic screening such as flagging laboratory lipid reports. Cascade screening, a form of targeted screening, is an ethically acceptable, cost-effective strategy for the identification of FH. However, for screening to be successful, medical practitioners need to be aware of the signs and diagnosis of FH and the benefits of early treatment.

Defining patients at extremely high risk for coronary artery disease in heterozygous familial hypercholesterolemia

AIM

Heterozygous patients with familial hypercholesterolemia (FH) are known to be associated with a high risk of coronary artery disease (CAD), which is a major determinant of their clinical outcome. The prognosis of heterozygous FH patients substantially varies, being dependent on the level of their CAD risk, and their therapeutic regimen should be individualized. We assessed critical levels of LDL-cholesterol (LDL-C) and Achilles tendon thickness (ATT) to identify heterozygous FH patients at "very high" risk for CAD.

METHODS

One hundred and nine heterozygous FH patients who had no history of CAD and had had their plasma lipid profile and ATT assessed before treatment were followed up until their first CAD event or 31 December 2010. Multivariable logistic regression models were used to analyze the correlation of LDL-C and/or ATT levels with the risk of developing CAD.

RESULTS

During the follow-up period, 21 of the 109 patients had a CAD event, diagnosed by coronary angiogram. Individuals in the highest tertile of LDL-C had a CAD risk 8.29-fold higher than those in the lowest tertile. Individuals in the highest tertile of the ATT group had a 7.82-fold higher CAD risk than those in the lowest tertile. Those who had either LDL-C ≥ 260 mg/dL or ATT ≥ 14.5 had a 23.94-fold higher CAD risk than those with LDL-C < 260 mg/dL and ATT <14.5 mm.

CONCLUSIONS

In heterozygous FH patients, LDL-C 260 mg/dL or higher and/or ATT 14.5 mm or thicker are useful markers for extracting patients at "very high" risk for CAD.

A new model of care for familial hypercholesterolaemia from Western Australia: closing a major gap in preventive cardiology

Familial hypercholesterolaemia (FH) is the most common monogenic cause of premature coronary artery disease. FH remains underdiagnosed and inadequately treated, with no national strategies for dealing with the problem. We report an executive summary of a comprehensive model of care for FH developed in Western Australia.

Monogenic pediatric dyslipidemias: classification, genetics and clinical spectrum

Monogenic disorders that cause abnormal levels of plasma cholesterol and triglycerides have received much attention due to their role in metabolic dysfunction and cardiovascular disease. While these disorders often present clinically during adulthood, some present most commonly in the pediatric population and can have serious consequences if misdiagnosed or untreated. This review provides an overview of monogenic lipid disorders that present with unusually high or low levels of plasma cholesterol and/or triglycerides during infancy, childhood and adolescence. Biochemical and genetic findings, clinical presentation and treatment options are discussed with an emphasis upon recent advances in our understanding and management of these monogenic disorders.