Waveform Periodicity Analysis of Complex Fractionated Electrograms in Patients With Persistent Atrial Fibrillation

Study Overview
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Brief Summary
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Atrial fibrillation (AF) has been the most frequently occurring, sustained arrhythmia, which causes significant morbidity and mortality. AF may not always be a totally random process. It can be maintained by stable and rapid reentrant circuits resulting in fibrillary conduction throughout the atria. During mapping of AF, difficulty is frequently encountered during the identification of culprit sites and an analysis of the wave propagation particularly when the electrogram signals demonstrate wide temporal and spatial disparities. Catheter ablation targeting regions with fractionated potentials or high frequencies during AF, has been previously proposed as a treatment strategy. However, the benefit of adjunctive CFAE (complex fractionated atrial electrogram) ablation or linear ablation after successful PVI (pulmonary vein isolation) was controversial based on the recent data from the Substrate and Trigger Ablation for Reduction of Atrial Fibrillation Trial Part II (STAR AF II) trial. Therefore, the optimal ablation strategy for persistent AF remains undetermined and an alternative approach has to be explored.

Detailed Description
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In this prospective trial, investigators will investigate the long-term efficacy of catheter ablation of non-paroxysmal AF, based on selective atrial substrate modification (e.g. wavefrom periodicity analysis, similarity, plus phase mapping) (1). The control group would be PV isolation alone. The primary end point is long-term recurrence of atrial arrhythmias. The secondary end points composite procedural termination, the safety of the procedure, recurrence of multiple procedures, and change of atrial and ventricular function after catheter ablation. The inclusion criteria, exclusion criteria, stepwise catheter ablation procedures (PVI and then substrate modification), and the follow-up procedure are the same as current treatment approaches in patients with non-paroxysmal AF.

Official Title
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A Randomized Controlled Study on the Waveform Periodicity Analysis of Complex Fractionated Electrograms in Patients With Persistent Atrial Fibrillation

Conditions
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Atrial Fibrillation, Persistent

Intervention / Treatment
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* Procedure: Pulmonary vein isolation
* Procedure: Substrate ablation(PRISM based)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients who sign the informed consent forms, and allow to be followed. Symptomatic AF refractory or intolerant to at least one Class 1 or 3 antiarrhythmic medication. Patients with persistent/permanent AF (sustained beyond seven days, or lasting less than seven days but necessitating pharmacologic or electrical cardioversion). Patients with age equal or greater than 20 years old regardless of gender. Exclusion Criteria: The presence of a atrial or ventricular thrombus. Patients who are allergic to or unsuitable for use with the contrast media. Pregnant patients or patients who are unavailable to receive X-ray. Patients with renal insufficiency. Patients had autonomic nervous system disorder (e.g. respiratory apnea) or previous catheter ablation in the LA or MAZE procedure. Patients who do not need atrial substrate modification (patients with non-paroxysmal AF respond to PVI in terms of procedural termination of AF). Patients with age less than 20 years old or greater than 90 years old regardless of gender.

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 90 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: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Pulmonary vein isolation + Waveform Periodicity Group<br>Pulmonary vein isolation + Substrate ablation | Procedure: Pulmonary vein isolation<br>* The 3D geometry of the LA will be created using CARTO 3 system (version 6) with UDM Module and VISITAG Optimum Device Performance (ODP) module. Continuous circumferential lesions will then be created encircling the right and left PV ostia using a 7.5F, 3.5-mm Thermocool SMARTTOUCH ablation catheter (Biosense Webster, Inc., Diamond Bar, CA, USA).Pentaray catheter will be used and facilitate the high density mapping of atrial substrate (PentarayTM, Biosense Webster Inc., Diamond Bar, CA, USA). The radiofrequency energy will be applied with contact force range 5-25 g continuously with a target Ablation Index target 380-400 on the posterior wall and 550 - 600 on the anterior wall and maximum power of 25-35W in a power control mode<br>Procedure: Substrate ablation(PRISM based)<br>* Substrate modification will be guided by waveform periodicity analysis. The User Defined Map of waveform periodicity analysis will be also created by CARTO 3 system (version 6) with and VISITAG ODP module. Pentaray catheter will be used and facilitate the high density mapping of atrial substrate (PentarayTM, Biosense Webster Inc., Diamond Bar, CA, USA). Substrate modification based on waveform periodicity analysis will be performed by using a 7.5F, 3.5-mm Thermocool SMARTTOUCH ablation catheter (Biosense Webster, Inc., Diamond Bar, CA, USA). The radiofrequency energy will be applied with contact force range 5-25 g continuously with a target Ablation Index target 380-400 on the posterior wall and 550 - 600 on the anterior wall and maximum power of 25-35W in a power control mode.<br>|
| Other: Pulmonary vein isolation group<br>Pulmonary vein isolation (Conventional treatment) | Procedure: Pulmonary vein isolation<br>* The 3D geometry of the LA will be created using CARTO 3 system (version 6) with UDM Module and VISITAG Optimum Device Performance (ODP) module. Continuous circumferential lesions will then be created encircling the right and left PV ostia using a 7.5F, 3.5-mm Thermocool SMARTTOUCH ablation catheter (Biosense Webster, Inc., Diamond Bar, CA, USA).Pentaray catheter will be used and facilitate the high density mapping of atrial substrate (PentarayTM, Biosense Webster Inc., Diamond Bar, CA, USA). The radiofrequency energy will be applied with contact force range 5-25 g continuously with a target Ablation Index target 380-400 on the posterior wall and 550 - 600 on the anterior wall and maximum power of 25-35W in a power control mode<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| changes in retention rate of normal sinus rhythm after catheter-based ablation of atrial fibrillation | A 24-hour Holter monitoring and/or ECG (7 days recordings) will be performed at 3, 6, 9, and 12 months post ablation and/or when the patients experience symptoms suggestive of a tachycardia after the ablation. Measurements: documentation of AF signal duration more than 30 seconds. | Baseline and 3, 6, 9 and 12 months after catheter-based ablation of atrial fibrillation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| LAD | Echocardiography will be performed at 3, 6, and 12 month post-ablation for cardiac chamber dimension and atrial & ventricular systolic function to assess the reverse remodeling of atrial substrate after catheter ablation of AF. Measurements: LAD [left atrial diameter] | after catheter ablation of atrial fibrillation 3, 6, 12 month | 
| LVEF | Echocardiography will be performed at 3, 6, and 12 month post-ablation for cardiac chamber dimension and atrial & ventricular systolic function to assess the reverse remodeling of atrial substrate after catheter ablation of AF. Measurements: LVEF [left ventricular ejection fraction] | after catheter ablation of atrial fibrillation 3, 6, 12 month | 
| e/e' | Echocardiography will be performed at 3, 6, and 12 month post-ablation for cardiac chamber dimension and atrial & ventricular systolic function to assess the reverse remodeling of atrial substrate after catheter ablation of AF. Measurements: e/e' [the ratio of early diastolic mitral inflow velocity to early diastolic mitral annulus velocity] | after catheter ablation of atrial fibrillation 3, 6, 12 month | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Catheter ablation, Mapping technique, Substrate mapping, Non-linear electrogram morphology analysis