Abstract 10960: Genetic Overlap of Acute Myocarditis and Inherited Cardiomyopathy

Background: Myocarditis may predispose to dilated cardiomyopathy (DCM) and sudden cardiac death (SCD). Familial data indicate a potential genetic susceptibility shared with arrhythmogenic cardiomyopathy (ACM). We present the first large-scale genotype-phenotype study of adults with acute myocarditis. Methods: A cohort comprising 336 consecutive patients with acute myocarditis was enrolled in London and Maastricht. All participants underwent targeted DNA sequencing for well-characterised cardiomyopathy-associated genes. The burden of rare protein altering variants (PAV) in ACM genes, DCM genes, and TTN specifically, were compared with local healthy controls sequenced on the same platform (n=1053). Case ascertainment was assessed against national hospital admission data. Results: We identified rare protein-altering variants in 23% of cases compared to 16% in controls (Δ+6.8%; p=0.021), with rare truncating variants (tv) in 6% of cases compared to Conclusion: We identified enrichment of cardiomyopathy gene variants in acute myocarditis patients, dominated by DSP-tv in those with normal LVEF and TTN-tv in those with reduced LVEF. Incorporation of genetic testing may be beneficial to identify such high-risk individuals and guide family screening in acute myocarditis patients.