P960Non-inducible ventricular arrhythmia soon after ventricular tachycardia ablation predicts long-term recurrence in patients with reduced ejection fraction
Authors: Kiyokuni M K , Narikawa M N , Kino T K , Taguchi Y T , Miyagawa S M , Nakayama N N , Yano H Y , Hosoda J H , Matsumoto K M , Sugano T S , Ishigami T I , Ishikawa T I , Kimura K K 
Published: June 2020

Abstract

Introduction
Radiofrequency (RF) ablation for ventricular arrhythmia in patients with reduced left ventricular ejection fraction (LVEF) is recognized to be one of the important strategies for suppressing the fatal arrhythmia events. Although, RF ablation for those patients has been performed for decades, the optimal endpoint remains unclear.

Hypothesis
We assessed the hypothesis that non-inducibility of any ventricular tachycardia (VT) or ventricular fibrillation (VF) immediately after VT ablation predicts long-term recurrence free rate of ventricular arrhythmia in patients who were diagnosed sustained VT with reduced LVEF.

Methods
From January 2014 to August 2019, we conducted a single center retrospective analysis for 127 consecutive patients with right or left ventricular arrhythmia who performed the first time RF ablation. Exclusion criteria were LVEF &gt;50% and RF ablations for premature ventricular contraction or for non-sustained VT. Then 26 patients (age 69 ± 7, male 92%) were enrolled. All of the ablation procedures were performed using irrigated RF catheters and 3D mapping systems. We defined non-inducible group as the patients without monomorphic VT (clinical monomorphic VT or non-clinical monomorphic VT with any cycle length), polymorphic VT and VF by electrophysiological study (EPS) immediately after the ablation. The primary endpoint of this study was a recurrence of any sustained VT and VF during the follow up period.

Results
All of 26 patients were followed for a mean of 30.9 ± 22.3months.Of those patients, 7 patients were non-inducible group and 19 patients were inducible group. Age, sex, body mass index, coronary risk factors, LVEF (non-inducible:42 ± 5% vs inducible:35 ± 10%, p = 0.12), renal function and the etiology of LV dysfunction did not differ between patients with non-inducible group and inducible group (all non-significant). Catheter ablation procedural characteristics including activation mapping (non-inducible:29% vs inducible:36%, p = 1.00), entrainment mapping (14% vs 42%, p = 0.19), substrate mapping (86% vs 95%, p = 0.47), pace-mapping (86% vs 68%, p = 0.63), RF time (21 ± 13vs 18 ± 21min, p = 0.70), number of RF applications (27 ± 13vs 27 ± 32, p = 0.89), fluoroscopy time (77 ± 50vs 87 ± 42min, p = 0.59) and procedure time (309 ± 87vs 282 ± 61min, p = 0.37) did not differ between two groups. Medications before and after the VT ablation did not differ between two groups. The recurrence of any sustained VT and VF significantly lower in patients with non-inducible group than those with inducible group (Figure).

Conclusion
This study demonstrated that, in patients with reduced LVEF presenting sustained VT who performed RF ablation, non-inducibility of any VT and VF immediately after RF ablation predicts long-term decreased risk of recurrence of any sustained VT and VF. Not only clinical but also non-clinical VT and VF may be targeted as well at the first time VT ablation for those patients.
Abstract Figure