The OneFreeze Study

Study Overview
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Brief Summary
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The One Freeze study is a prospective multi-center randomized controlled trial to assess the safety and efficacy of one vs. two cryoablations per pulmonary vein for the treatment of atrial fibrillation.

Detailed Description
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The One Freeze Trial is an investigator-initiated trial that has been developed by the Principals at the University of California, San Francisco (UCSF) and with full participation of the Steering Committee. One Freezel is a prospective multicenter randomized controlled trial with a goal to enroll and randomize a minimum of 90 study participants. Participants will be randomized in a 1:1 ratio to either PVI with a single freeze per pulmonary vein (1F Group) or to PVI with at least two freezes per pulmonary vein (2F Group). The One Freeze study's primary aim is to determine if one 3-minute cryoablation per pulmonary vein results in a lower composite adverse event score as compared to the traditional method of using two 3-minute cryoablations per pulmonary vein.

Official Title
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A Prospective Multi-center Randomized Controlled Trial to Assess the Safety and Efficacy of One vs. Two Cryoablations Per Pulmonary Vein for the Treatment of Atrial Fibrillation

Conditions
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Paroxysmal Atrial Fibrillation

Intervention / Treatment
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* Procedure: Atrial fibrillation catheter ablation using the Medtronic Arctic Front Ablation System


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Paroxysmal atrial fibrillation Age ≥ 18 years Life expectancy ≥ 1 year Willing and able to return to and comply with scheduled follow-up visits Willing and able to provide written informed consent Exclusion Criteria: History of > 5 electric cardioversions History of previous pulmonary vein isolation ablation for atrial fibrillation History of MAZE procedure Left ventricular EF ≤ 35% within the past 12 months Mechanical mitral valve Single PV > 30 mm in diameter, unless deemed appropriate by the site PI Stroke/TIA within the past 6 months Creatinine > 2.0 mg/dL within the past 6 months Pregnancy or desire to get pregnant within the next 12 months Current enrollment in an investigation or study of a cardiovascular device or investigational drug that would interfere with this study Mental impairment or other conditions, which may not allow the participant to understand the nature, significance and scope of the study Any other condition or circumstance that in the judgment of the Clinical Site Investigator that makes the participant unsuitable for the study

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: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: two 3-minute cryoablations<br>two 3-minute cryoablations per pulmonary vein during an atrial fibrillation ablation procedure | Procedure: Atrial fibrillation catheter ablation using the Medtronic Arctic Front Ablation System<br> <br> * Other names: Cryoballoon catheter ablation;|
| Active Comparator: One 3-minute cryoablation<br>One 3-minute cryoablation per pulmonary vein during an atrial fibrillation ablation procedure | Procedure: Atrial fibrillation catheter ablation using the Medtronic Arctic Front Ablation System<br> <br> * Other names: Cryoballoon catheter ablation;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Composite Score of Adverse Events | Composite score of adverse events (Range 0-20 points) will be calculated after the patient has completed follow-up. Higher scores indicate greater severity. Luminal Esophageal Temperature (LET) (0-2 points): 1-point if ≤20 degrees C, 2-points if ≤15 degrees C Phrenic nerve injury (0-3 points): 1-point if ≥30% decrease in compound muscle action potential (CMAP) or loss of phrenic nerve capture resulting in cessation of freeze (without movement of pacing catheter), 2-points if Phrenic nerve palsy lasting> 1 minute resolving on table, 3-points if Phrenic nerve palsy not resolving on the table Pulmonary (0-4 points): 1-point if persistent dry cough > 1 week post ablation, 4-points if Hemoptysis Gastrointestinal (GI) (0-6 points): 1-point if Gastroparesis symptoms, 3-points if Esophageal ulceration, 6-points if left atrial-esophageal fistula Pulmonary vein (PV) stenosis (0-5 points): 1-point if ≥50% luminal area, 4-points if ≥90% luminal area, 5-points if total occlusion | 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Participants free from symptomatic atrial fibrillation (AF) | Participants experiencing no episodes of AF greater than 30 seconds, excluding episodes documented in the blanking period (6 weeks post-ablation for paroxysmal AF patients). | 6 months and 12 months | 
| Atrial Fibrillation (AF) burden | AF burden is defined as the overall percentage of AF during the 14-day observed period on Holter monitoring at 6 months and 12 months. | 6 months, 12 months | 
| Procedure Time | The duration of the Pulmonary Vein Isolation procedure from first leg puncture to removal of ablation catheter | 4 - 8 hours | 
| Left Atrial Access time | Time it takes to gain transseptal access during the catheter ablation procedure | 4 - 8 hours | 
| Fluoroscopy Time | The amount of time in minutes (and milligray (mGy)/millisievert (mSv) dosage) of fluoroscopy used during the procedure | 4 - 8 hours | 
| Number of cryoablations needed to isolate each vein | Number of cryoablations needed to isolate each vein | 4 - 8 hours | 
| Acute success of the Pulmonary Vein Isolation (PVI) | percentage of pulmonary veins isolated during the catheter ablation procedure | 4 - 8 hours | 
| Individual Adverse Events | Number and severity of adverse events following the PVI procedure during the 12-month follow-up window | within 12 months after the Pulmonary Vein Isolation (PVI) | 
| Number of re-isolations required | Number of pulmonary veins requiring touch up for re-isolation after initial isolation was achieved. | 4 - 8 hours |