Isolation of Pulmonary Veins With the Aid of Magnetic Resonance Imaging

Study Overview
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Brief Summary
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The ALICIA-FA study will elucidate whether targeting atrial myocardial fibrosis identified by late gadolinium-enhanced magnetic resonance imaging (LGE-MRI) improves atrial fibrillation (AF) ablation outcomes.

Detailed Description
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Atrial fibrosis is a hallmark of the AF substrate. An accurate identification and localization of myocardial fibrosis areas prior to an ablation procedure by means of LGE-MRI might help to target atrial areas harboring AF, thereby improving ablation outcomes and reducing AF recurrences. In order to test this hypothesis, we will conduct a randomized study comparing the isolation of pulmonary veins without fibrosis imaging (conventional ablation procedure) vs. isolation of the pulmonary veins and pathological (fibrotic) tissue with the aid of LGE-MRI. Fibrotic tissue patches will be encircled and isolated in all patients in the active arm; furthermore, LGE-MRI will be used to identify, locate and guide ablation catheter to anatomical gaps surrounding pulmonary veins in re-do procedures. Eventually, we will identify an optimized ablation strategy in patients undergoing AF radiofrequency ablation on the basis of left atrium (LA) fibrosis characterization.

Official Title
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Isolation of Pulmonary Veins With the Aid of Magnetic Resonance Imaging

Conditions
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Atrial Fibrillation

Intervention / Treatment
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* Procedure: Conventional AF ablation
* Procedure: LGE-MRI guided AF ablation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients undergoing a first or subsequent ablation procedure. Pre-procedural 3 Tesla LGE-MRI. Referred for radiofrequency ablation of pulmonary veins (paroxysmal, persistent or long-standing AF). Signed informed consent. Exclusion Criteria: Claustrophobia. Refusal to participate in the study. Presence of atrial thrombus. LA anteroposterior diameter >55 mm. Major renal impairment. Contrast allergy. Pregnancy.

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: Conventional AF ablation.<br>A standard radiofrequency AF ablation procedure will be carried out without LGE information. | Procedure: Conventional AF ablation<br>* Conventional AF ablation will be carried out according to the standard procedure. Atrial anatomical MRI information will be integrated into the navigation system. Ablation procedure will be carried out with a Smart Touch® catheter (temperature 45 °C, 40W or 30W for anterior or posterior wall, respectively). Both in first and re-do procedures, procedure endpoint will be electrical isolation of all pulmonary veins.<br>|
| Experimental: LGE-MRI guided AF ablation.<br>Fibrosis information obtained from post-processed LGE-MRI will be used to guide AF ablation procedures. | Procedure: LGE-MRI guided AF ablation<br>* Post-processed LGE-MRI will be used to identify left atrial fibrotic patches and lesions surrounding pulmonary veins (re-do procedures). Both MRI atrial anatomical and fibrosis information will be integrated into the navigation system. Ablation procedures will be carried out with a SmartTouch® catheter (temperature 45°C, 40W or 30W for anterior or posterior wall, respectively). Procedural end-point for first ablation procedures will be isolation of all pulmonary veins, and encirclement and isolation of all atrial fibrotic areas. In re-do procedures, all left atrial fibrosis patches will be encircled and isolated and, for electrically non-isolated pulmonary veins, all anatomical gaps in lesions surrounding pulmonary veins (as identified in LGE-MRI) will be closed.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Freedom from atrial arrhythmias, lasting more than 30 sec. | Recurrence is defined as any documented episode of AF/atrial tachycardia lasting more than 30 seconds, after a blanking period of 3 months. | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Total time of radiofrequency application |  | During procedure | 
| Total X-ray time |  | During procedure | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Catheter Ablation, Radiofrequency, Fibrosis, Late-gadolinium enhanced MRI