Can a new freezing balloon tame a fluttering heart as well as the old one?

NCT ID NCT04704986

What the study statuses mean

This study's is highlighted.

Recruitment status, easiest to join first

Recruiting now
This trial is taking on new participants right now.
Not yet recruiting
Registered, but not yet taking participants.
By invitation only
Not open to general applications. Only people the study team invites can take part.
Paused
Paused for now. It may or may not start again.
Ongoing
Running, but no longer taking on new participants.
Completed This study
The trial has finished. Results may not be published yet.
Stopped early
Stopped early, before it reached the end. That can be for many reasons, including safety.
Cancelled
Cancelled before anyone took part.

Expanded access (not trials)

Expanded access
Not a trial. This treatment can be requested outside a study, case by case, for people who qualify.
Expanded access (paused)
Not a trial. The treatment can normally be requested outside a study, but is unavailable right now.
Expanded access (ended)
Not a trial. The treatment could once be requested outside a study, but no longer can.
Approved
The treatment has been approved, so it is available normally rather than through this programme.

When the status isn't known

Details not published
The full record has not been published yet, so there is little to show here.
Status unknown
This status has not been confirmed recently, so it may be out of date.

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

Phase 4

Runs after approval, following long-term safety and how well the treatment works in everyday use.

Participants

202 people

The number who actually took part.

Started

Mar 2021

Finished

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

18 years and older

Sex

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

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

  • University Hospital Basel

    Basel, 4031, Switzerland

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