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NCT Number: NCT04704986

Comparison of PolarX and the Arctic Front Cryoballoons for PVI in Patients With Symptomatic Paroxysmal AF

Pulmonary vein isolation (PVI) is an effective treatment for atrial fibrillation (AF). Single shot devices are increasingly used for PVI. Currently, Medtronic Arctic Front cryoballoon is the most frequently used single shot technology and hence is the benchmark for upcoming technologies. A novel cryoballoon technology has recently been introduced (PolarX, Boston Scientific). However, whether PolarX provides effectiveness similar to the standard-of-practice Medtronic Arctic Front cryoballoon is yet to be investigated. Given that PolarX was developed considering the reported limitations and potential failures associated with the Medtronic Arctic Front cryoballoon, it might be even more effective and safe for use in AF ablation procedures.

The aim of this trial is to compare the efficacy and safety of the PolarX Cryoballoon (Boston Scientific) and the Arctic Front Cryoballoon (Medtronic) in patients with symptomatic paroxysmal AF undergoing their first PVI.

This is an investigator-initiated, multicenter, randomized controlled, open-label trial with blinded endpoint adjudication. Given that the Medtronic Arctic Front Cryoballoon is the standard-of-practice for single shot PVI and the PolarX is the novel technology, this trial has a non-inferiority design.

The hypothesis with regards to the primary efficacy endpoint is that the PolarX Cryoballoon (Boston Scientific) shows lower efficacy compared to the Arctic Front Cryoballoon (Medtronic) and that therefore more episodes of first recurrence of any atrial arrhythmia between days 91 and 365 will be observed in patients with symptomatic paroxysmal AF undergoing their first PVI. Hence the alternative hypothesis postulates that the PolarX Cryoballoon is non-inferior to the Arctic Front Cryoballoon. Rejection of the null hypothesis is needed to conclude non-inferiority.

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Key information

Conditions

Paroxysmal Atrial Fibrillation Arrhythmias, Cardiac Atrial Fibrillation Cardiovascular Diseases Heart Diseases Pathologic Processes Pathological Conditions, Signs and Symptoms

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

University Hospital Basel, Basel, Switzerland

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Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

PVI using the Arctic Front Cryoballoon (Medtronic)

Device

Patients randomized to the Arctic Front cryoballoon group will undergo PVI using the Arctic Front Cryoballoon (Medtronic).

At the end of the procedure, an implantable cardiac monitor (Medtronic Reveal LINQ) will be implanted for the purpose of continuous arrhythmia monitoring.

Other names: Arctic Front Cryoballoon

PVI using the PolarX Cryoballoon (Boston Scientific)

Drug

Patients randomized to PolarX cryoballoon group will undergo PVI using the PolarX Cryoballoon (Boston Scientific).

At the end of the procedure, an implantable cardiac monitor (Medtronic Reveal LINQ) will be implanted for the purpose of continuous arrhythmia monitoring.

Other names: PolarX Cryoballoon

Primary outcomes

  1. Number of Patients With Recurrence of Any Atrial Tachyarrhythmia

    Time frame: days 91 to 365 post-ablation

    Number of patients with recurrence of any atrial tachyarrhythmia (atrial fibrillation [AF], atrial flutter [AFL] or atrial tachycardia [AT]) between days 91 and 365 post ablation as detected on continuous implantable cardiac monitor (ICM). AF, AFL or AT will qualify as a recurrence after ablation if it lasts 120 s or longer on ICM (the minimum programmable episode interval).

Secondary outcomes

  1. Number of Participants With Complications

    Time frame: days 0 to 30 post-ablation

    Composite endpoint composed of:

    • cardiac tamponade requiring drainage
    • persistent phrenic nerve palsy lasting >24 hours
    • serious vascular complications requiring intervention
    • stroke/TIA
    • atrioesophageal fistula
    • death

  2. Total Procedure Time

    Time frame: Day 1

    Total procedure time from femoral vein puncture to sheath removal

  3. Total Left Atrial (LA) Indwelling Time

    Time frame: Day 1

    Total LA indwelling time, from transseptal puncture to removal of LA catheters

  4. Total Cryoablation Time

    Time frame: Day 1

    procedural endpoint

  5. Total Number of Cryoapplications Per Patient/Per Vein

    Time frame: Day 1

    procedural endpoint

  6. Time to Effect

    Time frame: Day 1

    disappearance of PV-Signal; procedural endpoint

  7. Nadir Temperatures

    Time frame: Day 1

    procedural endpoint

  8. Total Fluoroscopy Time

    Time frame: Day 1

    procedural endpoint

  9. Radiation Dose

    Time frame: Day 1

    procedural endpoint

  10. Contrast Agent Usage

    Time frame: Day 1

    unit measure ml; procedural endpoint

  11. Number of Patients With Veins With PV Signals Visible Before Cryoablation

    Time frame: Day 1

    procedural endpoint

  12. Number of Participants With Phrenic Nerve Palsy

    Time frame: Day 1

    procedural endpoint

  13. Number of Patients With Recurrence of Atrial Tachyarrhythmia

    Time frame: between days 1 and 90 after ablation

    Follow up Endpoint

  14. Overall AF Burden = % Time in AF

    Time frame: 91-365 days

    Assessed by the ICM Core Lab post implantation

  15. Number of Hospital Admissions or Emergency Room Visits Because of Documented Recurrence of Atrial Arrhythmias

    Time frame: Day 0 (after ablation) until day 365 post-ablation

    based on telephone follow-up

  16. Number of Electrical Cardioversion Because of Documented Recurrence of Atrial Arrhythmias

    Time frame: Day 0 (post-ablation) to day 365 after ablation

    based on telephone follow-up

  17. Number of Repeat Ablation Procedure Because of Documented Recurrence of Atrial Arrhythmias

    Time frame: Day 1 - 365 postablation

    based on telephone follow-up

  18. Evolution of Quality of Life (QoL)

    Time frame: Change in score from BL to 12 months

    Evolution of Quality of Life (QoL) from BL to 12 months. Patients rated their health on a scale from 0 to 100, with 100 being the best possible score and 0 the worst possible score. A positive number in the outcome measure means that BL's health has improved at 12 months. A negative number in the outcome measure means that BL's health has declined at 12 months.

Sponsors and collaborators

Lead sponsor

Insel Gruppe AG, University Hospital Bern

Other

Collaborators

  • University Hospital, Basel, Switzerland

Registry information

Official study title

Comparison of the PolarX and the Arctic Front Cryoballoon for Pulmonary Vein Isolation in Patients With Symptomatic Paroxysmal Atrial Fibrillation - A Multi-Center Non-Inferiority Design Clinical Trial

Acronym: COMPARE-CRYO

Important dates

Study start
2021
Primary completion
2023
Study completion
2025
First posted
Jan 12, 2021
Registry last updated
Jul 24, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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