Atrial FibrillationPOLAR-HFNCT04461691
Cryoballoon Pulmonary Vein Isolation for Atrial Fibrillation With Heart Failure
A study testing Cryoballoon Pulmonary Vein Isolation in people with Atrial Fibrillation and Heart Failure, run by St. Josefs-Hospital Wiesbaden GmbH at 1 site in Germany.
Trial summary
The combination of atrial fibrillation (AF) and heart failure (HF) is common and implies a poor prognosis. Pulmonary vein isolation is an established method for the treatment of symptomatic AF in patients with normal heart function and has been shown to be more effective than drug therapy. Read more about this study
- Who is it for?
- Ages 18 to 99 years
- Conditions the study is for
- Atrial Fibrillation, Heart Failure, Cryoballon Ablation
- What is being tested?
- Cryoballoon Pulmonary Vein Isolation
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 1,420 participants
- Where
- 1 siteGermany
- Study dates
- 1 Jan 2018to 31 Aug 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 99 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Symptomatic paroxysmal or persistent atrial fibrillation
- Patients with severe heart failure (LVEF ≤40%, assigned to heart failure group)
- Patients with normal cardiac function (assigned to control group)
- Age > 18 years
- Consent capacity
Who cannot join
- Age under 18 years
- Pregnancy
- Lack of consent capacity
Trial locations and contacts
1 site in 1 country.
About this study
The combination of atrial fibrillation (AF) and heart failure (HF) is common and implies a poor prognosis. Pulmonary vein isolation is an established method for the treatment of symptomatic AF in patients with normal heart function and has been shown to be more effective than drug therapy. Recently, radiofrequency ablation has shown a positive effect in patients with AF and HF. POLAR-HF has been designed to investigate efficacy and safety of cryoballoon pulmonary vein isolation in patients with paroxysmal or persistent AF and severe HF (LVEF ≤ 40%).
- Conditions
- Atrial Fibrillation, Heart Failure, Cryoballon Ablation
- Being tested
- Cryoballoon Pulmonary Vein Isolation
- Medical subject headings
- Atrial Fibrillation, Heart Failure
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Cryoballoon Pulmonary Vein IsolationProcedure or surgery
Cryoballoon pulmonary vein isolation is a common method for catheter ablation of atrial fibrillation. Cryoenergy is applied through a balloon in a single-step approach resulting in necrosis by tissue freezing.
| Study group | Role | What they receive |
|---|---|---|
| Heart Failure | Other | Cryoballoon pulmonary vein isolation is a common method for catheter ablation of atrial fibrillation. Cryoenergy is applied through a balloon in a single-step approach resulting in necrosis by tissue freezing. Receives: Procedure: Cryoballoon Pulmonary Vein Isolation |
| Normal cardiac function | Other | Cryoballoon pulmonary vein isolation is a common method for catheter ablation of atrial fibrillation. Cryoenergy is applied through a balloon in a single-step approach resulting in necrosis by tissue freezing. Receives: Procedure: Cryoballoon Pulmonary Vein Isolation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Primary Outcome Measures (Number of recurrence)
Number of subjects with recurrence of atrial fibrillation, atrial flutter, atrial tachycardia or re-ablation after a blanking Period of 90 days after the initial cryoablation procedure
Measured: 60 months
Primary Outcome Measures (number of safety events)
- Number of subjects with a primary safety event including a composite of death from any cause, stroke or transient ischemic attack and serious procedure-related adverse events (Major Bleeding by International Society on Thrombosis and Hemostasis (ISTH) criteria, pericardial effusion, cerebrovascular or systemic embolism, phrenic paresis, major groin site complications requiring treatment)
Measured: 60 months
Secondary outcomes (6)
Secondary Outcome Measures (number of deaths)
Number of all-cause death
Measured: 60 months
Secondary Outcome Measures (procedural success)
- Incidence of acute procedural success assessed by successful isolation of all pulmonary veins
Measured: 60 months
Secondary Outcome Measures (rehospitalization)
- Number of subjects reporting a first unplanned rehospitalization for cardiovasvular causes
Measured: 60 months
Secondary Outcome Measures (procedure duration)
- Total procedure duration and left-atrial dwell time (in minutes)
Measured: 60 months
Secondary Outcome Measures (total time)
- Total fluoroscopy time (in minutes)
Measured: 60 months
Secondary Outcome Measures (total contrast use)
- Total contrast dye use (in milliliters)
Measured: 60 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Jul 2020
- Study start1 Jan 2018
- Primary completion31 Jan 2025
- Study completion31 Aug 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Atrial FibrillationStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Single group
- Model description
- Open label
- Masking
- None (open label)
- Enrolment
- 1,420 participants (actual)
Sponsor and investigators
- Lead sponsor
- St. Josefs-Hospital Wiesbaden GmbH
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Joachim Ehrlich, MD, Principal investigator, St. Josefs-Hospital Wiesbaden GmbHAndreas Boehmer, MD, Principal investigator, St. Josefs-Hospital Wiesbaden GmbH
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04461691
- Sponsor's protocol ID
- POLAR-HF
- Acronym
- POLAR-HF
- Status last verified
- Sep 2025
- First submitted
- 8 May 2020
- Last updated
- 12 Sep 2025
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Boehmer AA, Rothe M, Andrade JG, Wiedenmann L, Spork P, Schneider KY, Nussbaum E, Keim C, Weiss P, Dobre BC, Feickert S, Ruckes C, Dyrda K, Kaess BM, Nattel S, Ehrlich JR. Pulmonary Vein Isolation Only for Atrial Fibrillation With Heart Failure (POLAR-HF). JACC Clin Electrophysiol. 2026 Feb;12(2):264-273. doi: 10.1016/j.jacep.2025.09.041. Epub 2025 Nov 20.
PubMed 41263723
Study at a glance
From the registry record, last updated by the sponsor on 12 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Cryoballoon Pulmonary Vein Isolation for Atrial Fibrillation With Heart Failure
- ClinicalTrials.gov ID
- NCT04461691
- Acronym / sponsor ID
- POLAR-HF / POLAR-HF
- Conditions
- Atrial Fibrillation, Heart Failure, Cryoballon Ablation
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 1,420 participants (actual)
- Lead sponsor
- St. Josefs-Hospital Wiesbaden GmbHUniversity, hospital or other
- Study start
- 1 Jan 2018 (actual)
- Primary completion
- 31 Jan 2025 (actual)
- Study completion
- 31 Aug 2025 (actual)
- First posted
- 8 Jul 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The combination of atrial fibrillation (AF) and heart failure (HF) is common and implies a poor prognosis. Pulmonary vein isolation is an established method for the treatment of symptomatic AF in patients with normal heart function and has been shown to be more effective than drug therapy. Recently, radiofrequency ablation has shown a positive effect in patients with AF and HF. POLAR-HF has been designed to investigate efficacy and safety of cryoballoon pulmonary vein isolation in patients with paroxysmal or persistent AF and severe HF (LVEF ≤ 40%).
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Open label
| Arm | Type | Receives |
|---|---|---|
| Heart Failure | Other | Procedure: Cryoballoon Pulmonary Vein IsolationCryoballoon pulmonary vein isolation is a common method for catheter ablation of atrial fibrillation. Cryoenergy is applied through a balloon in a single-step approach resulting in necrosis by tissue freezing. |
| Normal cardiac function | Other | Procedure: Cryoballoon Pulmonary Vein IsolationCryoballoon pulmonary vein isolation is a common method for catheter ablation of atrial fibrillation. Cryoenergy is applied through a balloon in a single-step approach resulting in necrosis by tissue freezing. |
Who may qualify
- Ages
- 18 to 99 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Symptomatic paroxysmal or persistent atrial fibrillation
- Patients with severe heart failure (LVEF ≤40%, assigned to heart failure group)
- Patients with normal cardiac function (assigned to control group)
- Age > 18 years
- Consent capacity
Key exclusion criteria (3 listed)
- Age under 18 years
- Pregnancy
- Lack of consent capacity
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Cryoballoon Pulmonary Vein IsolationCryoballoon pulmonary vein isolation is a common method for catheter ablation of atrial fibrillation. Cryoenergy is applied through a balloon in a single-step approach resulting in necrosis by tissue freezing. | Procedure or surgery | Heart Failure, Normal cardiac function |
Primary outcome
Primary Outcome Measures (Number of recurrence)
Time frame: 60 months
Number of subjects with recurrence of atrial fibrillation, atrial flutter, atrial tachycardia or re-ablation after a blanking Period of 90 days after the initial cryoablation procedure
Primary Outcome Measures (number of safety events)
Time frame: 60 months
2. Number of subjects with a primary safety event including a composite of death from any cause, stroke or transient ischemic attack and serious procedure-related adverse events (Major Bleeding by International Society on Thrombosis and Hemostasis (ISTH) criteria, pericardial effusion, cerebrovascular or systemic embolism, phrenic paresis, major groin site complications requiring treatment)
6 secondary outcomes
Secondary Outcome Measures (number of deaths)
Time frame: 60 months
Secondary Outcome Measures (procedural success)
Time frame: 60 months
Secondary Outcome Measures (rehospitalization)
Time frame: 60 months
Secondary Outcome Measures (procedure duration)
Time frame: 60 months
Secondary Outcome Measures (total time)
Time frame: 60 months
Secondary Outcome Measures (total contrast use)
Time frame: 60 months
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 12 Sep 2025.
- Derived from this study: PubMed 41263723Boehmer AA, Rothe M, Andrade JG, Wiedenmann L, Spork P, Schneider KY, Nussbaum E, Keim C, Weiss P, Dobre BC, Feickert S, Ruckes C, Dyrda K, Kaess BM, Nattel S, Ehrlich JR. Pulmonary Vein Isolation Only for Atrial Fibrillation With Heart Failure (POLAR-HF). JACC Clin Electrophysiol. 2026 Feb;12(2):264-273. doi: 10.1016/j.jacep.2025.09.041. Epub 2025 Nov 20.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Joachim Ehrlich, MD principal investigator
St. Josefs-Hospital Wiesbaden GmbH
Andreas Boehmer, MD principal investigator
St. Josefs-Hospital Wiesbaden GmbH
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Cryoballoon Pulmonary Vein Isolation in people with Atrial Fibrillation and Heart Failure, run by St. Josefs-Hospital Wiesbaden GmbH at 1 site in Germany.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 12 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Germany. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Primary Outcome Measures (Number of recurrence) (time frame: 60 months). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04461691, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 12 Sep 2025.