310 CLINICAL COURSE AND CHARACTERISTICS OF ADVANCED HEART FAILURE ASSOCIATED WITH ARRHYTHMOGENIC CARDIOMYOPATHY

Abstract Background The prevalence and course of heart failure (HF) in arrhythmogenic cardiomyopathy (ACM) is unresolved, previous studies have mostly focused on the right-dominant variant disease, less prone to HF. Conversely, ACM variants with left ventricular (LV) involvement are now increasingly recognized, often initially ‘mis-diagnosed’ as dilated cardiomyopathy. Aim this study was therefore describe clinical advance HF full spectrum ACM. Methods We retrospectively reviewed records all patients diagnosed before 2021 from 3 Italian Cardiomyopathy Referral Centres (Azienda Ospedaliero Universitaria Careggi; Policlinico Sant’Orsola; Azienda Sant’Andrea). LV presence subepicardial late gadolinium enhancement (LGE) at least contiguous segments same short-axis slice cardiac magnetic resonance, independent whether it fulfilled 2010 Task Force criteria for (biventricular ACM) or not (left-dominant ACM); latter case, diagnosis reached after careful exclusion other differential diagnosis, only when one following features present: likely pathogenic/pathogenic genetic associated ACM; familial history electrocardiographic abnormalities suggestive involvement. Advanced defined NYHA functional class III/IV and/or referral transplantation. Median follow-up 6 years. Results Forty-four out 174 (25%) developed advanced HF: 10 34 Twenty were cardiomyopathy; such, development 17 cases preceded Five transplantation, by histological examination. In 22, median time 4 As compared those without, more present During course, 20 (46%) received appropriate ICD intervention, 13 experiencing an electrical storm. Twenty-six (59%) required HF-related hospitalization, 32 (72%) referred transplantation 25 ultimately receiving it. HF, experienced a higher rate mortality (36% vs. 6%; OR 3.5 [95%CI: 1.4-8.7], p=0.01) arrhythmic events (41% 11%; 2.4 1.1-5.0], p=0.02). Conclusions progression rare, occurs frequently increased risk.