Does VoltagE Guided Additional Ablation Improve Procedural Outcome of Atrial Fibrillation Ablation?

This study is designed to investigate whether pulmonary vein isolation(PVI) plus stepwise additional ablation approach based on the degree of low voltage area versus PVI only can improve procedure outcome in persistent atrial fibrillation(AF) patients.

Catheter ablation of AF is well accepted and widely performing treatment method of AF at present. Pulmonary vein isolation (PVI) which aims to electrical isolation of pulmonary veins is currently the standard therapy for AF. But some researchers proposed additional ablation strategy for persistent AF (PeAF) because abnormal atrial substrate may play a role in these patients.

However, there are inconsistent reports regarding a success rate of additional catheter ablation methods other than PVI. Thus, there still is no consensus on which strategy is appropriate in addition to PVI. One of these proposed options is complex fractioned atrial electrograms (CFAE) ablation. A meta-analysis of controlled trials comparing PVI alone versus PVI with CFAE reported that the addition of CFAE ablation results in a statistically significant increase in success rate for PeAF patients. Conversely, a prospective multicenter trial, The Substrate and Trigger Ablation for Reduction of Atrial Fibrillation Trial Part II (STAR-AF II) trial showed that recurrence rate of AF following catheter ablation treatment was not significantly reduced when either linear ablation or ablation of CFAE was performed in addition to PVI. The investigators have previously reported that posterior wall isolation in addition to PVI plus linear lesions reduced recurrence of AF following catheter ablation compared to PVI only but the long-term success rate were markedly lower in the CFAE-guide ablation in addition PVI plus linear lesions group than in PVI plus linear lesions group among PeAF patients. Although benefit of addition CFAE could be originated from modification of abnormal atrial substrate which is generated by structural and electrical remodeling, this possible benefit could be counterbalanced by increased formation of transmural ablation scar which may result in dysfunction of left atrium and recurrence of atrial tachyarrhythmia. A recent study have showed that extent of myocardial injury by catheter ablation was associated with left atrium functional deterioration in patients with paroxysmal AF and myocardial damage provoked that may contribute to recurrence of AF following catheter ablation.

Therefore, identification of PeAF patients who would benefit from additional ablation and tailored stepwise approach based on the identification may lead to reduction of iatrogenic myocardial injury and optimization of the result for the AF catheter ablation.

Recent data have shown that voltage guided mapping of left atrium is a powerful predictor of AF recurrence after PAI and voltage based ablation strategy showed promising result in terms of tailored approach. But, prospective, randomized clinical studies are needed to compare the result of a voltage-based AF ablation to the result of established strategies.

Eligibility Criteria:
Inclusion Criteria:

* Patients undergoing first-time catheter ablation for AF.
* Willing and able to provide informed consent
* Age greater than or equal to 18 years.

Exclusion Criteria:

* Patients who have previously undergone AF ablation
* Patients with more than mild mitral valve stenosis or mechanical mitral valve replacement
* Patients with chronic renal impairment with creatinine clearance rate of \<30 mL/min
* Patients who are pregnant