Randomized Trial of Segmental Versus Circumferential Antral Ablation in Paroxysmal Atrial Fibrillation

Study Overview
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Brief Summary
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An isolation-limited segmental antral approach to pulmonary vein isolation is as effective in achieving long-term freedom from atrial fibrillation as the standard anatomic, circumferential antral ablation.

Detailed Description
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This is a randomized controlled non-inferiority designed trial. Follow up: Patients will stop their anti-arrhythmic drugs 2 months post procedure. Follow-ups will involve clinical assessment, holter and/or loop recorders at 3, 6, 9, and 12 month intervals.

Official Title
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Randomized Trial of Segmental Versus Circumferential Antral Ablation in Paroxysmal Atrial Fibrillation

Conditions
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Paroxysmal Atrial Fibrillation

Intervention / Treatment
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* Procedure: Circumferential Antral Ablation
* Procedure: Segmental Antral ablation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Paroxysmal Atrial Fibrillation (PAF) for at least 6 months with at least 1 symptomatic episode during the previous 6 moths Patient must be felt to be candidates for Atrial Fibrillation (AF) ablation based on AF that is symptomatic and refractory or intolerant to at least one class 1 or 3 anti-arrhythmic agent Documentation of at least one episode of AF on 12 lead ECG, TTM or Holter monitor within 12 months of randomization in the trial Patient must be on continuous anti-coagulation with warfarin (INR 2-3) or fractionated subcutaneous heparin for >4 weeks prior to the ablation or they have undergone a recent (less than 48 hours before planned ablation) transoesphageal echocardiogram to exclude left atrial thrombus. Patient must provide written informed consent to participate in the clinical trial Exclusion Criteria: Contraindications to oral anticoagulants History of any previous ablation for AF Intracardiac thrombus AF due to reversible causes Pregnancy atriotomy scar (typically, MV or TV repair/replacement, ASD surgery, transplants)(CABG are okay)

Ages Eligible for Study
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Minimum Age: 18 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: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Circumferential<br>Completing a complete circle of RF lesions around the left and right pulmonary veins | Procedure: Circumferential Antral Ablation<br>* The goal is to complete ablation in all segments around the pulmonary veins until a circle of ablation lesions is created in the antrum with at least 30 seconds of ablation, 25W on the posterior surface, 30W on the anterior surface at each site, and change in the local electrogram. Entry and Exit block will be confirmed in each vein. The left superior pulmonary vein and left inferior pulmonary vein will be isolated with one circle, and the right superior and right inferior pulmonary veins will be isolated with one circle.<br>|
| Experimental: Segmental<br>Isolating the left and right pulmonary veins through RF lesions with a segmental antral approach. | Procedure: Segmental Antral ablation<br>* If the patient is in atrial fibrillation, ablation will begin in the segment with the highest frequency signals in the pulmonary vein antrum. If the patient is in sinus rhythm, mapping and ablation will occur during coronary sinus pacing. Segments with the earliest signals in the Lasso catheter will be targeted, and reassessed after each ablation lesion. This will continue in a segmental fashion on the antrum until pulmonary vein isolation is achieved. Lasso should be moved between veins between lesions to assess the earliest electrogram. Entry and exit block will be confirmed at each vein.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Freedom from atrial fibrillation | Symptomatic atrial fibrillation recurrence (without anti-arrhythmic med's) | six months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Procedure time | How long did the procedure take? | (4-6) hours From the time patient is draped to the time electrophysiology catheters are removed from the body (same day in the electrophysiology lab) | 
| Ablation Time | A cumulative measurement of the duration of ablation used during the pulmonary vein isolation procedure. | (4-6 hours) Measured during the procedure. | 
| Fluoroscopy Time | A cumulative measurement of flouroscopy time during the pulmonary vein isolation procedure. | (4-6 Hours) Measured during the procedure. | 
| complications | Did the patient experience any complication during the actual pulmonary vein isolation procedure or complication during follow-up related to the procedure? | 6 months |