Venoarterial ECMO-supported endocardial VT ablation in arrhythmogenic cardiomyopathy: a case series

Background Pathological changes in patients with arrhythmogenic cardiomyopathy (ACM) contribute to the development of arrhythmogenic substrates, thereby increasing the risk of ventricular arrhythmias and sudden cardiac death [1,2]. Catheter ablation has been confirmed to reduce the burden of ventricular tachycardia (VT) and the recurrence of electrical storms in ACM and is recommended by current guidelines and expert consensus [3,4,5,6]. However, the high risk of acute heart decompensation (AHD) makes it difficult to perform mapping during clinical VT, and extensive substrate-only ablation can increase the risk of complications. Objective To assess the feasibility, safety, and effectiveness of preventive venoarterial ECMO (VA-ECMO) support enabling VT mapping and ablation in high-risk ACM. Primary efficacy endpoint: 12-month freedom from VA recurrence. Safety endpoint: 30-day complications related to VA-ECMO or ablation. Acute endpoint: Non-inducibility at the end of the procedure. Methods Single-centre observational case series including consecutive ACM patients (following Padua Criteria 2020, [7]) with electrical storm or sustained VT at high risk of acute decompensation (PAINESD>15 or not hemodynamically tolerated). All patients underwent CT and CMR with ADAS-3D analysis. After preventive VA-ECMO, clinical VT was induced, and endocardial mapping with CARTO identified the critical isthmus, followed by ablation for acute termination. Programmed ventricular stimulation from two sites with two drive trains and up to three extrastimuli tested non-inducibility; additional ablation was performed if needed (additional VT induced). Follow-up relied on ICD/ILR interrogation. Results Ten males (46.2±14.1 years); mean LVEF 45±15%; 5/10 biventricular and 3/10 left-dominant phenotypes. At 12 months, 9/10 (90%) were free of VA recurrence [figure2]. No AHD occurred, and no ECMO- or ablation-related complications were observed within 30 days. VA-ECMO was removed in all patients at the end of the procedure; the median length of stay was 9 [7–14] days.[figure 1] Conclusion Preventive VA-ECMO support enabled comprehensive VT mapping with restrained ablation and high acute success, without AHD, translating into 90% 12-month freedom from VA in this high-risk ACM cohort. Larger prospective studies are required to confirm these findings.