a Novel Individualized Substrate Modification Approach for the Treatment of Long-standing Persistent Atrial Fibrillation

Study Overview
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Brief Summary
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The purpose of this study is to compare effectiveness of two substrate modification approaches in long-standing persistent atrial fibrillation patients, and hypothesized that a substrate-based, individualized substrate modification (ISM)approach should be superior to traditional stepwise ablation(SA). To the best of investigator's knowledge, this was the first study to evaluate the real substrate by means of electro-anatomic mapping and to perform true substrate modification in long standing persistent atrial fibrillation ablation(LPAF).

Detailed Description
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Catheter ablation (CA) is highly effective for paroxysmal atrial fibrillation(AF), it is modestly effective for long standing persistent atrial fibrillation ablation(LPAF) even with complex or combined approaches, which is mainly attributed to the substrate underlying AF remodeling. Severity of atrial fibrosis is closely associated with clinical outcomes after CA for AF . The more atrial scars and fibrosis present, the lower the success rate for AF ablation. Patients with LPAF have many more areas with scars and fibrosis than those with paroxysmal AF or non-AF controls. The MRI delayed enhancement technique provides a non-interventional tool for evaluation of atrial fibrosis, however, it must be performed in sinus rhythm.Three-dimensional electro anatomic mapping has proven as accurate as MRI and can be performed easily during AF ablation, thus providing a good tool for evaluation of atrial substrate during LPAF ablation. Although electro-anatomic mapping provided a desirable surrogate for delayed enhancement MRI to define AF substrate, there was an important technical issue to be considered. There were no good techniques to predict a desirable tip-tissue contact before the contact force catheter was applied. A poor tip-tissue contact could render the results of voltage mapping less reliable. On the other hand, excessively high contact force could increase the risk of steam pop and cardiac perforation during ablation. Hence it was important to use the contact force catheter to perform substrate mapping and ablation.

Official Title
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A Prospective Randomized Study of a Novel Individualized Substrate Modification Approach Versus Stepwise Ablation for the Treatment of Long-standing Persistent Atrial Fibrillation

Conditions
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Atrial Fibrillation

Intervention / Treatment
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* Procedure: individualized substrate modification
* Procedure: stepwise ablation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age ≥ 18 and ≤ 72years History of LPAF for ≥1 and ≤ 5 years Written informed consent provided Acceptance of catheter ablation treatment Acceptance of post-ablation follow-up Exclusion Criteria: Prior history of catheter ablation or surgical ablation Abnormal coagulation; contraindication for anti-coagulation left atrium diameter ≥ 55mm left atrium thrombus

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 72 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Individualized substrate modification<br>Circumferential pulmonary vein isolation(CPVI) ablation and left atrial roof linear ablation first,then substrate mapping in sinus rhythm followed by Individualized substrate modification. | Procedure: individualized substrate modification<br>* CPVI ablation and left atrial roof linear ablation first,then substrate mapping in sinus rhythm followed by individualized substrate modification.<br>|
| Active Comparator: Stepwise ablation<br>CPVI ablation,left atrial roof linear ablation,mitral isthmus linear ablation,complex fractionated atrial electrograms ablation step by step. | Procedure: stepwise ablation<br>* CPVI ablation,left atrial roof linear ablation,mitral isthmus linear ablation,complex fractionated atrial electrograms ablation step by step.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| atrial fibrillation free rate on or off antiarrhythmic drugs (AADs) after initial ablation |  | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of participants with adverse event | pericardial tamponade and thromboembolism event | 1 year | 
| Prevalence of recurrent atrial flutter |  | 1 year | 
| Proportion of pulmonary vein isolation |  | 1 year | 
| Proportion of acute pulmonary vein re-connection |  | 1 year | 
| Fluoroscopy exposure time |  | 1 year | 
| Total ablation time |  | 1 year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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long standing persistent atrial fibrillation, novel approach, ablation