Correlation of the Arrhythmia Mechanism and Substrate to Ablate Persistent Atrial Fibrillation Study

Study Overview
=================
Brief Summary
-----------------
This is a pilot study to assess the usefulness of ECG mapping, and enhanced MRI and PET scan imaging in identifying atrial fibrosis and arrhythmia circuits involved in persistent atrial fibrillation and in guiding an innovative AF catheter ablation strategy. It is hypothesized that identifying these critical arrhythmia circuits and atrial fibrosis with enhanced imaging and performing an individualized innovative AF catheter ablation will result in higher procedural success rates.

Detailed Description
-----------------
Pulmonary vein isolation catheter ablation for the treatment of persistent AF (PeAF)or longstanding persistent AF is associated with success rates of 40-50% at one year. Experimental models have shown that AF results in progressive structural changes due to electrical atrial remodeling, where AF burden correlates with atrial fibrosis. The optimal ablation strategy for patients with PeAF is not yet known. There is limited understanding of the critical mechanisms responsible for maintenance of AF in these patients. In this study ECG body mapping (ECGI) will be used to look for distinct electrical rotors in the atria. Delayed gadolinium enhanced magnetic resonance imaging (DE-MRI) will be used to assess the extent of left atrial fibrosis. In addition to PVI catheter ablation procedure, an ablation strategy guided by the results of the ECGI mapping and DE-MRI will be performed.A C-metahydroxyepherdrine (HED) PET scan will also be done pre-ablation to evaluate left atrial sympathetic denervation and any relationship to the initiation and/or maintenance of AF. Subjects will be seen at 3 and 6 months after ablation, with 12 lead ECG and 2-week loop monitoring done at each visit.

Official Title
-----------------
Correlation of Arrhythmia Mechanism and Substrate to Ablate Persistent Atrial Fibrillation:A Pilot Study

Conditions
-----------------
Persistent Atrial Fibrillation

Intervention / Treatment
-----------------
* Procedure: Catheter ablation


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Age ≥18 years and ≤ 80 years; Symptomatic persistent AF AND clinically indicated for AF catheter ablation At least one episode of AF lasting more than 7 days, documented on 12-lead ECG, Holter monitor, 2-week loop monitor or trans-telephonic monitor (TTM) within 12 months of enrollment in the study Able to provide informed consent. Exclusion Criteria: History of previous catheter or surgical ablation for AF Presence of intracardiac thrombus contraindication to systemic oral anticoagulation therapy Subjects with reversible causes of AF Antero-posterior left atrial dimension > 60 mm on echocardiography Severe valvular disease (mitral/aortic stenosis or regurgitation); Subjects that are pregnant or breastfeeding; Chronic kidney disease and creatinine clearance <50ml/min. Contraindication to MRI Imaging (e.g. permanent pacemaker, metallic implants, etc)

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Intervention/Treatment |
| --- |
|Procedure: Catheter ablation|Catheter ablation (in addition ot PVI) guided by ECGI mapping, and atrial fibrosis mapping (DE-MRI).|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Atrial Fibrillation (AF) Termination | AF termination resulting in restoration of sinus rhythm during ablation. | During catheter ablation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Radio frequency (RF) ablation time |  | During catheter ablation | 
| Procedure Duration | Total procedure duration | During catheter ablation | 
| Freedom from AF |  | 6 months | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Atrial fibrillation, Catheter ablation, Delayed gadolinium enhanced MRI, C-metahydroxyepherdrine (HED) PET scan, ECGI mapping, Atrial Fibrosis, Atrial sympathetic denervation