Epicardial ablation may not be necessary in all patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy and frequent ventricular tachycardia

We read with great interest the recent manuscript of Berruezo and colleagues who reported the results of a prospective multicentre study on ‘safety, long-term outcomes and predictors of recurrence after first-line combined endoepicardial ventricular tachycardia substrate ablation in arrhythmogenic cardiomyopathy’.1 With an aggressive approach of first-line combined endo- and epicardial ventricular tachycardia (VT) ablation in 41 patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) the authors observed recurrences of VT in 11 patients (26.8%) after a mean follow-up of 32.2 + 21.8 months. Two patients (5%) suffered from procedure-related complications due to epicardial access, including one death.1 Other researchers sought for alternative ablation strategies. Komatsu et al. examined whether epicardial substrate ablation from the endocardium was feasible. Patients with different cardiomyopathies (ischaemic cardiomyopathy, non-ischaemic dilated cardiomyopathy, ARVD/C) and sustained VT underwent combined endo- and epicardial mapping. An at least partial elimination of epicardial substrate by endocardial ablation could be achieved in the majority of patients with ischaemic cardiomyopathy and ARVD/C but only in a small minority of patients with non-ischaemic dilated cardiomyopathy.2 Santangeli et al.3 reported good long-term outcomes in ARVD/C patients undergoing endocardial-only ablation, emphasizing that epicardial approach should be reserved for patients with inducible VT despite extensive endocardial ablation. We propose a stepwise approach with an endocardial ablation first and additional epicardial ablation only if VT are still inducible after thorough endocardial ablation. We have shown that endocardial ablation of VT seems to be sufficient to suppress VT inducibility in about half of patients with ARVD/C and frequent VT. Our inducibility-guided ablation strategy yielded similar long-term results after endocardial and after combined endo- and epicardial ablation and may therefore be a reasonable strategy to reduce complications due to unnecessary epicardial ablation.4 Further randomized studies are warranted to compare these two strategies.