Can a new freezing balloon tame a fluttering heart as well as the old one?
NCT ID NCT04704986
First seen Jul 24, 2026 · Last updated Jul 24, 2026
Summary
This trial tests whether a newer cryoballoon device, PolarX, works as well as the standard Arctic Front device for treating paroxysmal atrial fibrillation (a type of irregular heartbeat). About 200 people having their first pulmonary vein isolation procedure will be randomly assigned to one of the two devices. The study will monitor heart rhythm for a year to see how well each device prevents the return of atrial fibrillation.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- a cryoballoon catheter device used to freeze and isolate pulmonary veins
- What this could lead to
- If the PolarX device proves as effective as the current standard, it could offer doctors another safe option for treating atrial fibrillation.
- What could go wrong
- This is a non-inferiority trial, so the new device may turn out to be less effective. Complications like heart lining inflammation or nerve injury are possible with any cryoballoon procedure.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
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Phase 4
Runs after approval, following long-term safety and how well the treatment works in everyday use.
- Participants
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202 people
The number who actually took part.
- Started
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Mar 2021
- Finished
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Jul 2025
- Lead sponsor
-
Other sponsor
The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
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18 years and older
- Sex
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Anyone
- Healthy volunteers
-
Not accepted
This study is not open to healthy volunteers. The entry requirements below say who it is open to.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
Inclusion Criteria: * Paroxysmal atrial fibrillation documented on a 12 lead electrocardiogram (ECG) or Holter monitor (lasting ≥30 seconds) within the last 24 months. According to current guidelines, paroxysmal is defined as any atrial fibrillation (AF) that converts to sinus rhythm within 7 days either spontaneously or by pharmacological or electrical cardioversion. * Candidate for ablation based on current AF guidelines * Continuous anticoagulation with warfarin (International Normalized Ratio \[INR\] 2-3) or a novel oral anticoagulant (NOAC) for ≥4 weeks prior to the ablation; or a transesophageal echocardiogram (TEE) that excludes left atrial (LA) thrombus ≤48 hours before ablation * Age of 18 years or older on the date of consent * Informed Consent as documented by signature (Appendix Informed Consent Form) Exclusion Criteria: * Previous LA ablation or LA surgery * AF due to reversible causes (e.g. hyperthyroidism, cardiothoracic surgery) * Intracardiac thrombus * Pre-existing pulmonary vein stenosis or pulmonary vein stent * Pre-existing hemidiaphragmatic paralysis * Contraindication to anticoagulation or radiocontrast materials * Cardiac valve prosthesis * Clinically significant (moderately-severe or severe) mitral regurgitation or stenosis * Myocardial infarction, percutaneous coronary intervention (PCI)/ percutaneous transluminal coronary angioplasty (PTCA), or coronary artery stenting during the 3-month period preceding the consent date * Cardiac surgery during the three-month interval preceding the consent date or scheduled cardiac surgery/transcatheter aortic valve implantation (TAVI) procedure * Significant congenital heart defect (including atrial septal defects or pulmonary vein abnormalities but not including patent foramen ovale) * New York Heart Association (NYHA) class III or IV congestive heart failure * Left ventricular ejection fraction (LVEF) \<35% * Hypertrophic cardiomyopathy (wall thickness \>1.5 cm) * Significant chronic kidney disease (CKD; estimated glomerular filtration rate \[eGFR\] \<30 μMol/L) * Uncontrolled hyperthyroidism * Cerebral ischemic event (stroke or TIA) during the six-month interval preceding the consent date * Ongoing systemic infections * History of cryoglobulinemia * Pregnancy\* * Life expectancy less than one (1) year per physician opinion * Currently participating in any other clinical trial of a drug, device or biological material during the duration of this study. * Unwilling or unable to comply fully with study procedures and follow-up. * To exclude pregnancy a blood test (human chorionic gonadotropin \[HCG\]) is used.
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
Contacts and locations
Locations
-
Inselspital, Bern University Hospital
Bern, 3010, Switzerland
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University Hospital Basel
Basel, 4031, Switzerland
More trials for these conditions
Other studies related to the condition(s) this trial covers.
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- Can a new heart ablation technique work without x-rays?
- Could a gentle sedation cocktail replace general anesthesia for heart ablation?
- Heart signals may reveal if a common AFib procedure will last
- Zapping the heart back to rhythm: a new device uses pulsed fields to treat atrial fibrillation
- Could a simple Chest-and-Arm patch replace bulky heart monitors?