Characterization of ventricular tachycardia ablation in end-stage heart failure patients with left ventricular assist device (CHANNELED-Registry)
Authors: Van Den Bruck J , Khalaph M , Sommer P , Duncker D , Estner H , Hohendanner F , Parwani A , Eckardt L , Doldi F , Lugenbiel P , Metzner A , Servatius H , Reichlin T , Steven D , Lueker J 
Published: May 2024

Abstract

Background
Left-ventricular-assist-devices (LVAD) are an established therapy for patients with end-stage heart failure. These patients are at high risk for ventricular tachycardia (VT) and ICD-shocks due to the arrhythmogenic substrate of the underlying cardiomyopathy itself and as the LVAD cannula might be arrhythmogenic, too.

Purpose
Data on catheter ablation of VT in LVAD patients are scarce and current evidence predominantly consists of case reports and small single-center series. This multicenter registry seeks to systematically assess the mechanism and origin of VA in LVAD patients and to evaluate procedural parameters and outcome of VT ablation in this special subset of patients.

Methods
Retrospective data of LVAD patients referred for VT ablation at 11 tertiary care centers between January 2017 and August 2023 were included in this multicenter registry. VT mechanisms, procedural data, clinical follow-up, and outcome were assessed.

Results
We report 49 patients (88% male, age 61±8 years) undergoing 51 ablation procedures included in this ongoing registry. The underlying cardiomyopathy was ischemic in 25/49 patients (51%) and nonischemic in 24/49 patients (49%) with a mean left ventricular ejection fraction of 21%±6% before LVAD implantation. Most catheter ablations were conducted after prior antiarrhythmic drug (AAD) treatment (15/51 on amiodarone, 13/51 on prior intensification of amiodarone treatment, 18/51 on prior combination of two or more AADs). A total of 75 VTs were targeted (39/51 transseptal, 3/51 retrograde aortic, 9/51 combined approaches) and 13/49 patients required VT ablation less than 1 month after LVAD implantation. Of the targeted VTs the majority (69%) were cardiomyopathy related and only 31% of the targeted VTs were related to the LVAD cannula. In 5/51 procedures access site complications and in 1/51 procedures a pericardial effusion occurred; one patient showed a post procedural oxygen desaturation; despite immediate intubation the patient deceased from hypoxic brain injury. No LVAD related complications were observed. A follow-up was available for 35/49 patients. During a median follow-up of 277 days (IQR 78-625 days), 5/35 patients were transplanted and 13/35 died. Patients died after a median time of 124 days (IQR 34-952 days) primarily from heart failure, sepsis, or intracranial bleeding. Of the remaining 17/35 patients, 7/17 patients were arrhythmia-free at a median follow-up of 212 days (IQR 78-639 days).

Conclusion
Although often chosen as last resort, catheter ablation of VT in LVAD patients is feasible and can be performed safely in this critically ill subset of heart failure patients in experienced centers. Intrinsic myocardial scar seems to be the dominant substrate in these patients but LVAD cannulae contribute to a significant number of VTs. In the presence of severely reduced LV function the VT recurrence remains high despite maximal therapy and prognosis of these patients is limited.