PO18 Referral for genetic evaluation in non-ischaemic cardiomyopathy: insights from a UK NHS teaching hospital

Background The 2023 ESC cardiomyopathy guidelines recommend genetic testing for patients with suspected inherited non-ischaemic cardiomyopathy (NICM), particularly when “red flag” features such as early disease onset, conduction abnormalities, or a positive family history are present. In England, the NHS National Genomic Test Directory (NGTD) specifies clear eligibility criteria for genomic testing in dilated (DCM), hypertrophic (HCM), and arrhythmogenic right ventricular cardiomyopathy (ARVC). For DCM and HCM, genotype prediction tools such as the MADRID Genotype Score and Mayo HCM Genotype Predictor Score estimate the likelihood of detecting a pathogenic variant. Under-referral in these groups risks missed opportunities for precision care and cascade family screening. Purpose To evaluate adherence to the ESC guidelines and NGTD criteria for genetic testing in NICM patients at an NHS teaching hospital and to assess referral rates among those with a high predicted genotype-positivity based on the MADRID and Mayo scores. Methods We conducted a retrospective review of adult patients diagnosed with NICM at an NHS Trust between January and December 2024. Data on demographics, phenotype (assessed by cardiac MRI), ECG findings, and family history were extracted from electronic health records. Genetic testing eligibility was defined according to NGTD criteria, which include confirmed DCM (inclusive of ESC-defined non-dilated left ventricular cardiomyopathy), HCM, or ARVC with suspected monogenic aetiology. For DCM patients, the MADRID Genotype Score (range 0–5) was calculated, with scores ≥3 indicating a high likelihood of a genotype-positive result. For HCM patients, the Mayo HCM Score (range 0–4) was calculated, with scores ≥2 indicating a high likelihood. Referral rates to clinical genetics or for genetic testing were compared between all eligible patients and these high-likelihood subgroups. Results Of 244 NICM patients, 116 (47.5%) met NGTD/ESC criteria for genetic testing, but only 54 (22.1%) were referred. Within the DCM subgroup (n=192), 10 patients (5.2%) had a high MADRID score (≥3), yet only 1 was referred. By contrast, in the HCM subgroup (n=50), 8 patients (16%) had a high Mayo score (≥2), of whom 6 were referred. Family history was undocumented in 53.3% of cases. Other commonly missed eligibility indicators included unexplained conduction abnormalities and age at disease onset. Conclusion This audit highlights considerable under-referral for genetic testing among NICM patients, particularly those with DCM, within an NHS teaching hospital. This includes patients at the highest predicted risk of pathogenic variants. Integration of NGTD criteria and genotype prediction scores into clinical workflows could optimise patient identification for genetic testing, enhance cascade screening, and facilitate earlier targeted interventions. A structured referral proforma and tailored educational initiatives for clinicians have been proposed, alongside plans for wider NHS implementation and ongoing evaluation to monitor improvements across multiple centres.