PROSPECTIVE EVALUATION OF THE FAMCAT TOOL TO IDENTIFY FAMILIAL HYPERCHOLESTEROLAEMIA (FH) IN PRIMARY CARE

Problem

About one in 250 people (0.4%) has familial hypercholesterolaemia (FH), characterized by elevated plasma low-density lipoprotein cholesterol (LDL-C) and early onset cardiovascular disease. Mutations in any of three genes (LDLR, APOB and PCSK9) are known to cause autosomal dominant FH, however the majority are thought to have a polygenic trait, caused by common LDL-C-raising and other variants. FH is underdiagnosed- less than 10% of predicted in the UK is known. To help address this, the 2019 NHS long term plan, aims to improve FH detection through the NHS genomics programme. For FH adults, NICE suggests high dose lipid lowering therapy. Despite increased risks of early heart disease, many patients are unaware of their condition, and there are no national screening programmes in England. Previous studies have suggested screening in primary care is able to identify a large % of undiagnosed individuals.

Approach

Aim: To prospectively evaluate usability of the FAMCAT tool to identify FH in primary care.

Methods: Design: Feasibility study in 5 Lambeth and Southwark practices, London. Intervention: Use of the validated FAMCAT tool, in GP electronic health records, to identify adults aged 18 years and over with a high probability of FH.

Findings

We identified 50/52,388 (0.1%) diagnosed FH individuals and 269/52,388 (0.5%) individuals ranked very high-risk FH (“high probability FH”) that were not previously diagnosed. Of those diagnosed with FH, only 30/50 (60%) were prescribed high/medium potency lipid lowering drugs. For high probability FH groups (n=2009): 19% were prescribed high/medium potency lipid lowering drugs, (70.7% received no lipid lowering medicines), lipid specialist referrals were <0.01% in the last 12 months, and relevant family history was missing for 84.5%. Around 52% of high probability FH individuals were aged below 50 years.

Consequences

We demonstrated a feasible diagnostic and ascertainment pilot in South London using the FAMCAT tool. We identified a large burden of undiagnosed, untreated and undertreated individuals at high risk of FH. We found >50% of high risk individuals were aged below 50 years, suggesting this group would benefit from targeted interventions to reduce avoidable cardiovascular disease and morbidity.