for people ages 18 years and up (full criteria)
at San Francisco, California and other locations
study started
estimated completion
Byron Lee



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.

Official Title

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


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.


Paroxysmal Atrial Fibrillation Atrial Fibrillation Atrial fibrillation catheter ablation using the Medtronic Arctic Front Ablation System Cryoballoon catheter ablation two 3-minute cryoablations One 3-minute cryoablation


You can join if…

Open to people ages 18 years and up

  • 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

You CAN'T join if...

  • 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


  • University of California, San Francisco
    San Francisco California 94122 United States
  • Virginia Mason Medical Center
    Seattle Washington 98101 United States

Lead Scientist

  • Byron Lee
    CLINICAL INTERESTS: Dr. Lee is a Cardiologist and a Cardiac Electrophysiologist. His main clinical interests include conduction disorders, arrhythmias, catheter ablation, implantable devices (including pacemakers, defibrillators and biventricular defibrillators), lead extraction, atrial fibrillation, atrial flutter, supraventricular tachycardias, ventricular tachycardias, and sudden death.


in progress, not accepting new patients
Start Date
Completion Date
University of California, San Francisco
Study Type
Last Updated