Characterization of ventricular tachycardia ablation in end-stage heart failure patients with left ventricular assist device (CHANNELED registry).

Aims: Patients with left ventricular assist devices (LVADs) are at high risk for ventricular tachycardia (VT), and data on VT ablation in patients with LVAD are scarce. This multicentre registry assessed the mechanism of VT, procedural parameters, and outcome of VT ablation in patients with LVAD (NCT06063811).

Methods and results: Data of patients with LVAD referred for VT ablation at nine tertiary care centres were collected retrospectively. Parameters included VT mechanisms, procedural data, VT recurrence, and mortality. Overall, 69 patients (90% male, mean age 60.7 ± 8.4 years) undergoing 72 ablation procedures were included. Most procedures were conducted after intensification of antiarrhythmic drug (AAD) treatment (18/72; 25%) or a prior combination of ≥2 AADs (31/72; 43%). Endocardial low-voltage areas were detected in all patients. The predominant VT mechanism was scar-related re-entry (76/96 VTs; 79%), and 19/96 VTs (20%) were related to the LVAD cannula. Non-inducibility of any VT was achieved in 28/72 procedures (39%). No LVAD-related complication was observed. The extent of endocardial scar was associated with VT recurrence. The median follow-up was 283 days (interquartile range 70-587 days). A total of 3/69 patients were lost to follow-up, 10/69 (14%) were transplanted, 26/69 (38%) died, and 16/69 (23%) patients were free from VT.

Conclusion: Although often a last resort, VT ablation in patients with LVAD is feasible and safe when performed in experienced centres. These patients suffer from a high scar burden, and cardiomyopathy-associated rather than cannula-related scar seems to be the dominant substrate. Ventricular tachycardia recurrence is high despite extensive treatment, and the overall prognosis is limited.