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.


Eligibility Criteria:
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.