The Ablate-by-LAW Study

Study Overview
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Brief Summary
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Of all the determinants of lesion creation during atrial fibrillation (AF) ablation, left atrial wall thickness (LAWT), as measured with multi-detector cardiac tomography (MDCT) is one key element that has been evaluated in some retrospective analyses but is not yet used per protocol to modulate the radiofrequency delivery. Adapting ablation index (AI) to LAWT would be very useful in standardising the ablation procedure with parameters fitted to every patient, enabling the development of a personalized approach that will both: i) increase efficacy by performing transmural lesions to prevent the formation of conduction gaps in the initial lesion set, and ii) increase safety by preventing excessive RF delivery on thin wall areas related to procedural complications, such as cardiac perforation or atrio-esophageal fistula. The investigators sought to evaluate the feasibility, safety, efficacy and reproducibility of guiding AF ablation procedures with the integrated MDCT-derived LAWT information.

Official Title
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Feasibility and Efficacy of Tailoring Ablation Index to Left Atrial Wall Thickness During Atrial Fibrillation Ablation: The Ablate By-LAW Study

Conditions
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Atrial Fibrillation

Intervention / Treatment
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* Procedure: Personalized atrial fibrillation ablation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age > 18 years. Indication for paroxysmal atrial fibrillation ablation. Signed informed consent. Exclusion Criteria: Age < 18 years. Pregnancy. Previous AF ablation procedure (REDO).

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Personalized AF ablation using MDCT-derived LAWT<br>Pre-procedural MDCT images will be analysed in Teknon Medical Center (core-lab), using ADAS-3D™ (Galgo Medical, Barcelona, Spain) to obtain 3D atrial wall thickness maps that will be introduced into CARTO® navigation system (Biosense Webster, Diamond Bar, California, US). PVI will be performed point-by-point, aiming to complete a RF circle around the PV ostia (nephroid shape) on the 3D geometry using a ThermoCool® SmartTouch® 3.5-mm irrigated tip contact force-sensing RF ablation catheter (Biosense Webster, Inc.). AI targets will be defined by LAWT on the thickness color map, as follows: Thickness < 1 mm (red): 300; 1-2 mm (yellow): 350; 2-3 mm (green): 400; 3-4 mm (blue): 450; > 4 mm (purple): 500. The recommended power settings to reach these AI values will be, in general, 35 W for the posterior wall and 40 W for the anterior wall. Wherever local AWT is > 3 mm (green and blue colors), an increased RF power (50 W) will be permitted. | Procedure: Personalized atrial fibrillation ablation<br>* Atrial fibrillation (AF) ablation adapting the ablation index (AI) target in a point-by-point manner, according the local left atrial wall thickness (LAWT), as measured by multidetector cardiac tomography (MDCT)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Arrhythmia-free survival | 1-year atrial arrhythmia-free survival | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Acute procedural outcomes | Procedure times | 1 day | 
| Peri-procedural complications |  | 1 month | 
| REDO outcomes | Mean LAWT at late reconnection sites | 2 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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atrial fibrillation, catheter-based ablation, radiofrequency ablation, pulmonary vein isolation, left atrial wall thickness, multidetector cardiac tomography