Trial Outcomes & Findings for Comparison of PolarX and the Arctic Front Cryoballoons for PVI in Patients With Symptomatic Paroxysmal AF (NCT NCT04704986)
NCT ID: NCT04704986
Last Updated: 2026-07-24
Results Overview
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).
Recruitment status
COMPLETED
Study phase
PHASE4
Target enrollment
202 participants
Primary outcome timeframe
days 91 to 365 post-ablation
Results posted on
2026-07-24
Participant Flow
A total of 202 subjects were randomized at 2 sites in Switzerland between March 29, 2021 and June 14, 2022. The last 3-year follow-up visit occurred on July 24, 2025.
Participant milestones
| Measure |
PVI Using the Arctic Front Cryoballoon (Medtronic)
Pulmonary vein isolation using the Arctic Front Cryoballoon (Medtronic)
|
PVI Using the PolarX Cryoballoon (Boston Scientific)
Pulmonary vein isolation using the PolarX Cryoballoon (Boston Scientific)
|
|---|---|---|
|
Overall Study
STARTED
|
102
|
100
|
|
Overall Study
COMPLETED
|
102
|
99
|
|
Overall Study
NOT COMPLETED
|
0
|
1
|
Reasons for withdrawal
Withdrawal data not reported
Baseline Characteristics
Race and Ethnicity were not collected from any participant.
Baseline characteristics by cohort
| Measure |
PVI Using the Arctic Front Cryoballoon (Medtronic)
n=102 Participants
Pulmonary vein isolation using the Arctic Front Cryoballoon (Medtronic)
|
PVI Using the PolarX Cryoballoon (Boston Scientific)
n=99 Participants
Pulmonary vein isolation using the PolarX Cryoballoon (Boston Scientific)
|
Total
n=201 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age, Continuous
|
62.2 years
STANDARD_DEVIATION 9.3 • n=102 Participants
|
62.2 years
STANDARD_DEVIATION 10.1 • n=99 Participants
|
62.2 years
STANDARD_DEVIATION 9.7 • n=201 Participants
|
|
Sex: Female, Male
Female
|
24 Participants
n=102 Participants
|
35 Participants
n=99 Participants
|
59 Participants
n=201 Participants
|
|
Sex: Female, Male
Male
|
78 Participants
n=102 Participants
|
64 Participants
n=99 Participants
|
142 Participants
n=201 Participants
|
|
Race and Ethnicity Not Collected
|
—
|
—
|
0 Participants
Race and Ethnicity were not collected from any participant.
|
PRIMARY outcome
Timeframe: days 91 to 365 post-ablationNumber 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).
Outcome measures
| Measure |
PVI Using the PolarX Cryoballoon (Boston Scientific)
n=99 Participants
Pulmonary vein isolation using the PolarX Cryoballoon (Boston Scientific)
|
PVI Using the Arctic Front Cryoballoon (Medtronic)
n=102 Participants
Pulmonary vein isolation using the Arctic Front Cryoballoon (Medtronic)
|
|---|---|---|
|
Number of Patients With Recurrence of Any Atrial Tachyarrhythmia
|
41 Participants
|
48 Participants
|
SECONDARY outcome
Timeframe: days 0 to 30 post-ablationComposite endpoint composed of: * cardiac tamponade requiring drainage * persistent phrenic nerve palsy lasting \>24 hours * serious vascular complications requiring intervention * stroke/TIA * atrioesophageal fistula * death
Outcome measures
| Measure |
PVI Using the PolarX Cryoballoon (Boston Scientific)
n=99 Participants
Pulmonary vein isolation using the PolarX Cryoballoon (Boston Scientific)
|
PVI Using the Arctic Front Cryoballoon (Medtronic)
n=102 Participants
Pulmonary vein isolation using the Arctic Front Cryoballoon (Medtronic)
|
|---|---|---|
|
Number of Participants With Complications
|
5 Participants
|
0 Participants
|
SECONDARY outcome
Timeframe: Day 1Total procedure time from femoral vein puncture to sheath removal
Outcome measures
| Measure |
PVI Using the PolarX Cryoballoon (Boston Scientific)
n=99 Participants
Pulmonary vein isolation using the PolarX Cryoballoon (Boston Scientific)
|
PVI Using the Arctic Front Cryoballoon (Medtronic)
n=102 Participants
Pulmonary vein isolation using the Arctic Front Cryoballoon (Medtronic)
|
|---|---|---|
|
Total Procedure Time
|
73.1 minutes
Standard Deviation 27.3
|
68.1 minutes
Standard Deviation 24.8
|
SECONDARY outcome
Timeframe: Day 1Total LA indwelling time, from transseptal puncture to removal of LA catheters
Outcome measures
| Measure |
PVI Using the PolarX Cryoballoon (Boston Scientific)
n=99 Participants
Pulmonary vein isolation using the PolarX Cryoballoon (Boston Scientific)
|
PVI Using the Arctic Front Cryoballoon (Medtronic)
n=102 Participants
Pulmonary vein isolation using the Arctic Front Cryoballoon (Medtronic)
|
|---|---|---|
|
Total Left Atrial (LA) Indwelling Time
|
49.9 minutes
Standard Deviation 19.0
|
46.6 minutes
Standard Deviation 16.2
|
SECONDARY outcome
Timeframe: Day 1procedural endpoint
Outcome measures
| Measure |
PVI Using the PolarX Cryoballoon (Boston Scientific)
n=99 Participants
Pulmonary vein isolation using the PolarX Cryoballoon (Boston Scientific)
|
PVI Using the Arctic Front Cryoballoon (Medtronic)
n=102 Participants
Pulmonary vein isolation using the Arctic Front Cryoballoon (Medtronic)
|
|---|---|---|
|
Total Cryoablation Time
|
1007 seconds
Standard Deviation 335
|
1021 seconds
Standard Deviation 318
|
SECONDARY outcome
Timeframe: Day 1procedural endpoint
Outcome measures
| Measure |
PVI Using the PolarX Cryoballoon (Boston Scientific)
n=99 Participants
Pulmonary vein isolation using the PolarX Cryoballoon (Boston Scientific)
|
PVI Using the Arctic Front Cryoballoon (Medtronic)
n=102 Participants
Pulmonary vein isolation using the Arctic Front Cryoballoon (Medtronic)
|
|---|---|---|
|
Total Number of Cryoapplications Per Patient/Per Vein
|
5.6 number of applications
Standard Deviation 2.1
|
5.7 number of applications
Standard Deviation 1.9
|
SECONDARY outcome
Timeframe: Day 1disappearance of PV-Signal; procedural endpoint
Outcome measures
| Measure |
PVI Using the PolarX Cryoballoon (Boston Scientific)
n=99 Participants
Pulmonary vein isolation using the PolarX Cryoballoon (Boston Scientific)
|
PVI Using the Arctic Front Cryoballoon (Medtronic)
n=102 Participants
Pulmonary vein isolation using the Arctic Front Cryoballoon (Medtronic)
|
|---|---|---|
|
Time to Effect
|
52.6 seconds
Standard Deviation 29.9
|
51.5 seconds
Standard Deviation 29.9
|
SECONDARY outcome
Timeframe: Day 1procedural endpoint
Outcome measures
| Measure |
PVI Using the PolarX Cryoballoon (Boston Scientific)
n=99 Participants
Pulmonary vein isolation using the PolarX Cryoballoon (Boston Scientific)
|
PVI Using the Arctic Front Cryoballoon (Medtronic)
n=102 Participants
Pulmonary vein isolation using the Arctic Front Cryoballoon (Medtronic)
|
|---|---|---|
|
Nadir Temperatures
|
-59.0 degrees Celsius
Standard Deviation 5.5
|
-51.4 degrees Celsius
Standard Deviation 5.4
|
SECONDARY outcome
Timeframe: Day 1procedural endpoint
Outcome measures
| Measure |
PVI Using the PolarX Cryoballoon (Boston Scientific)
n=99 Participants
Pulmonary vein isolation using the PolarX Cryoballoon (Boston Scientific)
|
PVI Using the Arctic Front Cryoballoon (Medtronic)
n=102 Participants
Pulmonary vein isolation using the Arctic Front Cryoballoon (Medtronic)
|
|---|---|---|
|
Total Fluoroscopy Time
|
15.4 minutes
Standard Deviation 7.4
|
15.7 minutes
Standard Deviation 7.9
|
SECONDARY outcome
Timeframe: Day 1procedural endpoint
Outcome measures
| Measure |
PVI Using the PolarX Cryoballoon (Boston Scientific)
n=99 Participants
Pulmonary vein isolation using the PolarX Cryoballoon (Boston Scientific)
|
PVI Using the Arctic Front Cryoballoon (Medtronic)
n=102 Participants
Pulmonary vein isolation using the Arctic Front Cryoballoon (Medtronic)
|
|---|---|---|
|
Radiation Dose
|
615.2 cG*cm²
Standard Deviation 658.6
|
756.9 cG*cm²
Standard Deviation 888.3
|
SECONDARY outcome
Timeframe: Day 1unit measure ml; procedural endpoint
Outcome measures
| Measure |
PVI Using the PolarX Cryoballoon (Boston Scientific)
n=99 Participants
Pulmonary vein isolation using the PolarX Cryoballoon (Boston Scientific)
|
PVI Using the Arctic Front Cryoballoon (Medtronic)
n=102 Participants
Pulmonary vein isolation using the Arctic Front Cryoballoon (Medtronic)
|
|---|---|---|
|
Contrast Agent Usage
|
54.7 millilitres
Standard Deviation 19.7
|
56.2 millilitres
Standard Deviation 23.0
|
SECONDARY outcome
Timeframe: Day 1procedural endpoint
Outcome measures
| Measure |
PVI Using the PolarX Cryoballoon (Boston Scientific)
n=99 Participants
Pulmonary vein isolation using the PolarX Cryoballoon (Boston Scientific)
|
PVI Using the Arctic Front Cryoballoon (Medtronic)
n=102 Participants
Pulmonary vein isolation using the Arctic Front Cryoballoon (Medtronic)
|
|---|---|---|
|
Number of Patients With Veins With PV Signals Visible Before Cryoablation
|
80 Participants
|
75 Participants
|
SECONDARY outcome
Timeframe: Day 1procedural endpoint
Outcome measures
| Measure |
PVI Using the PolarX Cryoballoon (Boston Scientific)
n=99 Participants
Pulmonary vein isolation using the PolarX Cryoballoon (Boston Scientific)
|
PVI Using the Arctic Front Cryoballoon (Medtronic)
n=102 Participants
Pulmonary vein isolation using the Arctic Front Cryoballoon (Medtronic)
|
|---|---|---|
|
Number of Participants With Phrenic Nerve Palsy
|
5 Participants
|
0 Participants
|
SECONDARY outcome
Timeframe: between days 1 and 90 after ablationFollow up Endpoint
Outcome measures
| Measure |
PVI Using the PolarX Cryoballoon (Boston Scientific)
n=99 Participants
Pulmonary vein isolation using the PolarX Cryoballoon (Boston Scientific)
|
PVI Using the Arctic Front Cryoballoon (Medtronic)
n=102 Participants
Pulmonary vein isolation using the Arctic Front Cryoballoon (Medtronic)
|
|---|---|---|
|
Number of Patients With Recurrence of Atrial Tachyarrhythmia
|
50 Participants
|
67 Participants
|
SECONDARY outcome
Timeframe: 91-365 daysAssessed by the ICM Core Lab post implantation
Outcome measures
| Measure |
PVI Using the PolarX Cryoballoon (Boston Scientific)
n=99 Participants
Pulmonary vein isolation using the PolarX Cryoballoon (Boston Scientific)
|
PVI Using the Arctic Front Cryoballoon (Medtronic)
n=102 Participants
Pulmonary vein isolation using the Arctic Front Cryoballoon (Medtronic)
|
|---|---|---|
|
Overall AF Burden = % Time in AF
|
0 percentage of time in AF
Interval 0.0 to 0.11
|
0 percentage of time in AF
Interval 0.0 to 0.18
|
SECONDARY outcome
Timeframe: Day 0 (after ablation) until day 365 post-ablationbased on telephone follow-up
Outcome measures
| Measure |
PVI Using the PolarX Cryoballoon (Boston Scientific)
n=99 Participants
Pulmonary vein isolation using the PolarX Cryoballoon (Boston Scientific)
|
PVI Using the Arctic Front Cryoballoon (Medtronic)
n=102 Participants
Pulmonary vein isolation using the Arctic Front Cryoballoon (Medtronic)
|
|---|---|---|
|
Number of Hospital Admissions or Emergency Room Visits Because of Documented Recurrence of Atrial Arrhythmias
|
6 Participants
|
3 Participants
|
SECONDARY outcome
Timeframe: Day 0 (post-ablation) to day 365 after ablationbased on telephone follow-up
Outcome measures
| Measure |
PVI Using the PolarX Cryoballoon (Boston Scientific)
n=99 Participants
Pulmonary vein isolation using the PolarX Cryoballoon (Boston Scientific)
|
PVI Using the Arctic Front Cryoballoon (Medtronic)
n=102 Participants
Pulmonary vein isolation using the Arctic Front Cryoballoon (Medtronic)
|
|---|---|---|
|
Number of Electrical Cardioversion Because of Documented Recurrence of Atrial Arrhythmias
|
3 Participants
|
4 Participants
|
SECONDARY outcome
Timeframe: Day 1 - 365 postablationbased on telephone follow-up
Outcome measures
| Measure |
PVI Using the PolarX Cryoballoon (Boston Scientific)
n=99 Participants
Pulmonary vein isolation using the PolarX Cryoballoon (Boston Scientific)
|
PVI Using the Arctic Front Cryoballoon (Medtronic)
n=102 Participants
Pulmonary vein isolation using the Arctic Front Cryoballoon (Medtronic)
|
|---|---|---|
|
Number of Repeat Ablation Procedure Because of Documented Recurrence of Atrial Arrhythmias
|
14 Participants
|
13 Participants
|
SECONDARY outcome
Timeframe: Change in score from BL to 12 monthsEvolution 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.
Outcome measures
| Measure |
PVI Using the PolarX Cryoballoon (Boston Scientific)
n=99 Participants
Pulmonary vein isolation using the PolarX Cryoballoon (Boston Scientific)
|
PVI Using the Arctic Front Cryoballoon (Medtronic)
n=102 Participants
Pulmonary vein isolation using the Arctic Front Cryoballoon (Medtronic)
|
|---|---|---|
|
Evolution of Quality of Life (QoL)
|
-3.27 change in score from BL to 12 months
Standard Deviation 14.38
|
-2.56 change in score from BL to 12 months
Standard Deviation 16.83
|
Adverse Events
PVI Using the Arctic Front Cryoballoon (Medtronic)
Serious events: 13 serious events
Other events: 7 other events
Deaths: 0 deaths
PVI Using the PolarX Cryoballoon (Boston Scientific)
Serious events: 19 serious events
Other events: 9 other events
Deaths: 0 deaths
Serious adverse events
| Measure |
PVI Using the Arctic Front Cryoballoon (Medtronic)
n=102 participants at risk
Pulmonary vein isolation using the Arctic Front Cryoballoon (Medtronic)
|
PVI Using the PolarX Cryoballoon (Boston Scientific)
n=99 participants at risk
Pulmonary vein isolation using the PolarX Cryoballoon (Boston Scientific)
|
|---|---|---|
|
Nervous system disorders
Phrenic nerve palsy lasting >24 h
|
0.00%
0/102 • From enrollment until day 365 postablation
|
5.1%
5/99 • Number of events 5 • From enrollment until day 365 postablation
|
|
Cardiac disorders
First Redo Ablation
|
12.7%
13/102 • Number of events 13 • From enrollment until day 365 postablation
|
14.1%
14/99 • Number of events 14 • From enrollment until day 365 postablation
|
Other adverse events
| Measure |
PVI Using the Arctic Front Cryoballoon (Medtronic)
n=102 participants at risk
Pulmonary vein isolation using the Arctic Front Cryoballoon (Medtronic)
|
PVI Using the PolarX Cryoballoon (Boston Scientific)
n=99 participants at risk
Pulmonary vein isolation using the PolarX Cryoballoon (Boston Scientific)
|
|---|---|---|
|
Cardiac disorders
Hospital or emercency department admission for recurrence of atrial arrhythmias
|
2.9%
3/102 • Number of events 3 • From enrollment until day 365 postablation
|
6.1%
6/99 • Number of events 6 • From enrollment until day 365 postablation
|
|
Cardiac disorders
Electrocardioversion for recurrence of atrial arrhythmias
|
3.9%
4/102 • Number of events 4 • From enrollment until day 365 postablation
|
3.0%
3/99 • Number of events 3 • From enrollment until day 365 postablation
|
Additional Information
Prof. Dr. med. Tobias Reichlin
Insel Gruppe AG, Inselspital Bern, Department of Cardiology
Phone: +41 31 664 00 50
Email: [email protected]
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place