The Yield and Clinical Impact of Genetic Testing in Older Patients with Dilated Cardiomyopathy

Genetic testing in patients with dilated cardiomyopathy (DCM) is increasingly used to guide clinical management, but international guidance does not endorse genetic testing for older patients. This study sought to explore the yield and impact of genetic testing in older patients with DCM.

Consecutive and unrelated genotyped patients with DCM were retrospectively recruited in a single referral centre. The yield of genetic testing was examined by age group. Genotype positive patients above and below 55 years of age were compared for a primary composite endpoint of end-stage heart failure (ESHF) or malignant ventricular arrhythmia (MVA).Six hundred and eighty-six patients (62.1% male, median [IQR] age 50 [37, 59] years) were recruited; 166 (24.2%) were genotype-positive. Sixty of 308 (19.5%) patients over 55 years of age were genotype-positive with 18 (30%) harbouring variants in genes associated with a higher risk of MVA.During a median follow-up of 50 months, twenty-one of 148 (14.2%) genotype-positive patients without baseline MVA had the primary composite endpoint with no significant difference between age groups (11/94 (11.7%) of those aged <55 years and 10/54 (18.5%) ≥55 years, log rank p value = 0.4).

One fifth of older patients with DCM carry disease causing genetic variants, including those associated with a higher risk of MVA. Adverse event rates in older genotype-positive patients with DCM are comparable to their younger counterparts. These data highlight the value of extending genetic testing to older patients with DCM.