ArrhythmiaNCT01360008
FREEZE Cohort Study
An observational study of Arrhythmia, run by Stiftung Institut fuer Herzinfarktforschung at 37 sites in 6 countries.
Trial summary
Safety and efficacy in radiofrequency (RF) or cryoballoon atrial fibrillation (AF) ablation will be investigated in a cohort study design in experienced electrophysiologic (EP) centers analyzing propensity-matched cohorts. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Arrhythmia
- How many people
- 4,071 participants
- Where
- 37 sitesin 6 countries
- Study dates
- Apr 2011to Apr 2017
- Phase
- Observational
- 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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Patients with AF ablation targeting
Who may be able to join
- Documented paroxysmal AF (2 episodes of PAF within the last 3 months) or Persistent AF (lasting < 1 year)
- First ablation of AF
- Age ≥18 years
- Documented inefficacy of at least 1 AAD not including β-blockers
- Written informed consent
Who cannot join
- Longstanding persistent AF lasting > 1 year
- Acute coronary syndrome (ACS)
- Heart failure NYHA IV
- Thrombocytosis, thrombocytopenia
- Any condition contraindicating chronic anticoagulation
- Stroke or TIA within 6 months prior to ablation
Show all 9Show fewer
- Uncontrolled hyperthyroidism
- Pregnancy
- Life expectancy < 1 year
Trial locations and contacts
37 sites in 6 countries.
37 sites in 6 countries
Germany30 sites
Klinikum Aschaffenburg
Aschaffenburg, 63739
Herz-Zentrum Bad Krozingen
Bad Krozingen
Kerckhoff-Klinik
Bad Nauheim
Herz- und Gefäßklinik Bad Neustadt; Klinik für Kardiologie II
Bad Neustadt an der Saale, 97616
Herz- und Diabeteszentrum
Bad Oeynhausen
Deutsches Herzzentrum Berlin (Kardiologie)
Berlin, 13353
Vivantes Klinikum Am Urban
Berlin
Klinikum Bielelfeld - Klinik für Kardiologie und internistische Intensivmedizin
Bielefeld, 33604
Universitätsklinikum Bonn (Med. Klinik und Poliklinik II)
Bonn, 53105
Klinikum Coburg
Coburg
St. Vinzenz Hospital Köln-Nippes
Cologne, 50733
Praxisklinik Herz und Gefäße
Dresden
Elisabeth-Krankenhaus Essen; Klinik für Kardiologie und Angiologie
Essen, 45138
Städt. Klinikum Frankfurt Höchst
Frankfurt, 65929
Cardioangiologisches Centrum Bethanien - CCB
Frankfurt
Universitäres Herzzentrum Eppendorf
Hamburg, 20246
Asklepios Klinik St. Georg
Hamburg
Universitäres Herzzentrum
Hamburg
Klinikum Siloah
Hanover, 30449
Universitätsklinikum Heidelberg
Heidelberg, 69120
Städt. Klinikum Hildesheim
Hildesheim
Klinikum Ingolstadt
Ingolstadt, 85049
Westpfalz-Klinikum GmbH
Kaiserslautern
Universitätsklinik Schleswig-Holstein Campus Lübeck
Lübeck, 23538
Universitätsmedizin Mainz
Mainz, 55131
Isar Herzzentrum München
München
Krankenhaus München Bogenhausen
München
Universitätsklinikum Münster
Münster
Klinikum Traunstein
Traunstein, 83278
Schwarzwald-Baar-Klinikum Villingen-Schwenningen GmbH
Villingen-Schwenningen, 78052
South Africa3 sites
Sunninghill Hospital
Johannesburg, 2196
Panorama Medi-Clinic
Panorama, 7500
Milpark Hospital
Parktown West, 2193
United States1 site
Mission Hospital, Inc.
Asheville, North Carolina, 28803
About this study
Safety and efficacy in radiofrequency (RF) or cryoballoon atrial fibrillation (AF) ablation will be investigated in a cohort study design in experienced electrophysiologic (EP) centers analyzing propensity-matched cohorts.
Read the detailed description
Prior to participation in the cohort-study each EP center had to perform a minimum of 50 RF or 50 cryoballoon approaches. To insure the consecutiveness of recruitment, participating centers have to announce the intention to ablate the patient prior to the procedure to the coordinating center in Ludwigshafen. After inclusion of 500 patients with well accepted criteria for AF ablation undergoing cryoballoon pulmonary vein isolation (PVI) in experienced german EP centers inclusion of patients will be extended to european centers. A total of 4.000 patients will be included in the cohort-study, 2.000 in both the cryoballoon and the RF arm.
- Conditions
- Arrhythmia
- Keywords
- Cardiac arrhythmia, Catheter ablation, Cohort Study, cryoballoon, radiofrequency
- Medical subject headings
- Arrhythmias, Cardiac
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Cryo ablation | Patients with first Ablation of atrial fibrillation treated by cryo ablation | |
| RF ablation | Patients with first Ablation of atrial fibrillation treated by Radio frequency ablation |
What is being measured
The primary outcome is the main question the study is designed to answer.
AF recurrency rate (any detected episode lasting > 30 sec) at 12 months follow up
Measured: Admission to hospital until 12 months thereafter
Secondary outcomes (5)
Comparison of complication rates (any complications and major complications) at 12 months follow-up
Measured: Admission to hospital until 12 months thereafter
Specific complication aspects with respect to phrenic nerve palsy and PV stenosis
Measured: Admission to Hospital until 12 months thereafter
Efficacy (AF recurrency rates), safety (complication rates), and procedural parameters in cryoballoon or RF ablation as means for assessing advantages of preprocedural CT or MRI scan performing 3 D anatomy of the left atrium and pulmonary veins
Measured: Admission to Hospital until 12 months thereafter
Persistent AF: Impact on efficacy analyzing procedural aspects in cryoballoon PVI
Measured: Admission to Hospital until 12 months thereafter
Real-time ECG-monitoring of PV-isolation during freezing: Does the microcircular mapping catheter add significant benefit to the cryoballoon procedure
Measured: Admission to Hospital until 12 months thereafter
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 May 2011 (estimated)
- Study startApr 2011
- Primary completionJan 2016
- Study completionApr 2017
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (6)Papers the sponsor has linked to this study.
- Other trials for ArrhythmiaStudies 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 4,071 participants (actual)
Sponsor and investigators
- Lead sponsor
- Stiftung Institut fuer Herzinfarktforschung
- Sponsor type
- University, hospital or other
- Collaborators
- Medtronic
- Responsible party
- Sponsor
- Investigators
- Ellen Hoffmann, MD, Principal investigator, Klinikum Bogenhausen, München
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01360008
- Sponsor's protocol ID
- FREEZE
- Status last verified
- Sep 2017
- First submitted
- 13 May 2011
- Last updated
- 27 Jun 2019
- Results posted
- No
- Data monitoring committee
- Yes
- Individual data sharing
- No: De-identified patient data will be published after end of follow up period
Publications
Pongratz J, Kuniss M, Wu LQ, Tebbenjohanns J, Nolker G, Dorwarth U, Kuck KH, Senges J, Hoffmann E, Straube F; FREEZE Cohort Study Investigators. Quality of life after cryoballoon vs. radiofrequency ablation in atrial fibrillation: a subanalysis of the FREEZE cohort study. Front Cardiovasc Med. 2026 Oct 9;13:1877743. doi: 10.3389/fcvm.2026.1877743. eCollection 2026.
PubMed 42920489Pongratz J, Kuniss M, Wu L, Tebbenjohanns J, Nolker G, Dorwarth U, Kuck KH, Jochen S, Hoffmann E, Straube F; FREEZE Cohort Study Investigators. Impact of intracardiac echocardiography usage on the safety of cryoballoon atrial fibrillation ablation: Subanalysis of the prospective FREEZE cluster cohort study. J Cardiovasc Electrophysiol. 2023 Oct;34(10):2029-2039. doi: 10.1111/jce.16060. Epub 2023 Sep 8.
PubMed 37681996Metzner A, Straube F, Tilz RR, Kuniss M, Noelker G, Tebbenjohanns J, Andresen D, Wieneke H, Stellbrink C, Franke J, Dorwarth U, Carion PL, Holbrook R, Hochadel M, Senges J, Hoffmann E, Kuck KH; FREEZE Cohort Study Investigators. Electrophysiology lab efficiency comparison between cryoballoon and point-by-point radiofrequency ablation: a German sub-analysis of the FREEZE Cohort study. BMC Cardiovasc Disord. 2023 Jan 9;23(1):8. doi: 10.1186/s12872-022-03015-8.
PubMed 36624380Hoffmann E, Straube F, Wegscheider K, Kuniss M, Andresen D, Wu LQ, Tebbenjohanns J, Noelker G, Tilz RR, Chun JKR, Franke A, Stellbrink C, Garcia-Alberola A, Dorwarth U, Metzner A, Ouarrak T, Brachmann J, Kuck KH, Senges J; FREEZE Cohort Study Investigators. Outcomes of cryoballoon or radiofrequency ablation in symptomatic paroxysmal or persistent atrial fibrillation. Europace. 2019 Sep 1;21(9):1313-1324. doi: 10.1093/europace/euz155.
PubMed 31199860Straube F, Dorwarth U, Ammar-Busch S, Peter T, Noelker G, Massa T, Kuniss M, Ewertsen NC, Chun KR, Tebbenjohanns J, Tilz R, Kuck KH, Ouarrak T, Senges J, Hoffmann E; FREEZE Cohort Investigators. First-line catheter ablation of paroxysmal atrial fibrillation: outcome of radiofrequency vs. cryoballoon pulmonary vein isolation. Europace. 2016 Mar;18(3):368-75. doi: 10.1093/europace/euv271. Epub 2015 Oct 25.
PubMed 26504108Straube F, Dorwarth U, Vogt J, Kuniss M, Heinz Kuck K, Tebbenjohanns J, Garcia Alberola A, Chun KR, Souza JJ, Ouarrak T, Senges J, Brachmann J, Lewalter T, Hoffmann E. Differences of two cryoballoon generations: insights from the prospective multicentre, multinational FREEZE Cohort Substudy. Europace. 2014 Oct;16(10):1434-42. doi: 10.1093/europace/euu162. Epub 2014 Jul 3.
PubMed 24994074
Study at a glance
From the registry record, last updated by the sponsor on 27 Jun 2019. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- FREEZE Cohort Study
- ClinicalTrials.gov ID
- NCT01360008
- Acronym / sponsor ID
- FREEZE
- Conditions
- Arrhythmia
- Keywords
- Cardiac arrhythmia, Catheter ablation, Cohort Study, cryoballoon, radiofrequency
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 4,071 participants (actual)
- Lead sponsor
- Stiftung Institut fuer HerzinfarktforschungUniversity, hospital or other
- Collaborators
- Medtronic
- Study start
- Apr 2011
- Primary completion
- Jan 2016 (actual)
- Study completion
- Apr 2017 (actual)
- First posted
- 25 May 2011 (estimated)
- 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.
Safety and efficacy in radiofrequency (RF) or cryoballoon atrial fibrillation (AF) ablation will be investigated in a cohort study design in experienced electrophysiologic (EP) centers analyzing propensity-matched cohorts.
Detailed description
Prior to participation in the cohort-study each EP center had to perform a minimum of 50 RF or 50 cryoballoon approaches. To insure the consecutiveness of recruitment, participating centers have to announce the intention to ablate the patient prior to the procedure to the coordinating center in Ludwigshafen. After inclusion of 500 patients with well accepted criteria for AF ablation undergoing cryoballoon pulmonary vein isolation (PVI) in experienced german EP centers inclusion of patients will be extended to european centers. A total of 4.000 patients will be included in the cohort-study, 2.000 in both the cryoballoon and the RF arm.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Cryo ablation | – | –Patients with first Ablation of atrial fibrillation treated by cryo ablation |
| RF ablation | – | –Patients with first Ablation of atrial fibrillation treated by Radio frequency ablation |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Patients with AF ablation targeting
Key inclusion criteria (5 listed)
- Documented paroxysmal AF (2 episodes of PAF within the last 3 months) or Persistent AF (lasting < 1 year)
- First ablation of AF
- Age ≥18 years
- Documented inefficacy of at least 1 AAD not including β-blockers
- Written informed consent
Key exclusion criteria (9 listed)
- Longstanding persistent AF lasting > 1 year
- Acute coronary syndrome (ACS)
- Heart failure NYHA IV
- Thrombocytosis, thrombocytopenia
- Any condition contraindicating chronic anticoagulation
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
AF recurrency rate (any detected episode lasting > 30 sec) at 12 months follow up
Time frame: Admission to hospital until 12 months thereafter
5 secondary outcomes
Comparison of complication rates (any complications and major complications) at 12 months follow-up
Time frame: Admission to hospital until 12 months thereafter
Specific complication aspects with respect to phrenic nerve palsy and PV stenosis
Time frame: Admission to Hospital until 12 months thereafter
Efficacy (AF recurrency rates), safety (complication rates), and procedural parameters in cryoballoon or RF ablation as means for assessing advantages of preprocedural CT or MRI scan performing 3 D anatomy of the left atrium and pulmonary veins
Time frame: Admission to Hospital until 12 months thereafter
Persistent AF: Impact on efficacy analyzing procedural aspects in cryoballoon PVI
Time frame: Admission to Hospital until 12 months thereafter
Real-time ECG-monitoring of PV-isolation during freezing: Does the microcircular mapping catheter add significant benefit to the cryoballoon procedure
Time frame: Admission to Hospital until 12 months thereafter
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 27 Jun 2019.
- Derived from this study: PubMed 42920489Pongratz J, Kuniss M, Wu LQ, Tebbenjohanns J, Nolker G, Dorwarth U, Kuck KH, Senges J, Hoffmann E, Straube F; FREEZE Cohort Study Investigators. Quality of life after cryoballoon vs. radiofrequency ablation in atrial fibrillation: a subanalysis of the FREEZE cohort study. Front Cardiovasc Med. 2026 Oct 9;13:1877743. doi: 10.3389/fcvm.2026.1877743. eCollection 2026.
- Derived from this study: PubMed 37681996Pongratz J, Kuniss M, Wu L, Tebbenjohanns J, Nolker G, Dorwarth U, Kuck KH, Jochen S, Hoffmann E, Straube F; FREEZE Cohort Study Investigators. Impact of intracardiac echocardiography usage on the safety of cryoballoon atrial fibrillation ablation: Subanalysis of the prospective FREEZE cluster cohort study. J Cardiovasc Electrophysiol. 2023 Oct;34(10):2029-2039. doi: 10.1111/jce.16060. Epub 2023 Sep 8.
- Derived from this study: PubMed 36624380Metzner A, Straube F, Tilz RR, Kuniss M, Noelker G, Tebbenjohanns J, Andresen D, Wieneke H, Stellbrink C, Franke J, Dorwarth U, Carion PL, Holbrook R, Hochadel M, Senges J, Hoffmann E, Kuck KH; FREEZE Cohort Study Investigators. Electrophysiology lab efficiency comparison between cryoballoon and point-by-point radiofrequency ablation: a German sub-analysis of the FREEZE Cohort study. BMC Cardiovasc Disord. 2023 Jan 9;23(1):8. doi: 10.1186/s12872-022-03015-8.
- Derived from this study: PubMed 31199860Hoffmann E, Straube F, Wegscheider K, Kuniss M, Andresen D, Wu LQ, Tebbenjohanns J, Noelker G, Tilz RR, Chun JKR, Franke A, Stellbrink C, Garcia-Alberola A, Dorwarth U, Metzner A, Ouarrak T, Brachmann J, Kuck KH, Senges J; FREEZE Cohort Study Investigators. Outcomes of cryoballoon or radiofrequency ablation in symptomatic paroxysmal or persistent atrial fibrillation. Europace. 2019 Sep 1;21(9):1313-1324. doi: 10.1093/europace/euz155.
- Derived from this study: PubMed 26504108Straube F, Dorwarth U, Ammar-Busch S, Peter T, Noelker G, Massa T, Kuniss M, Ewertsen NC, Chun KR, Tebbenjohanns J, Tilz R, Kuck KH, Ouarrak T, Senges J, Hoffmann E; FREEZE Cohort Investigators. First-line catheter ablation of paroxysmal atrial fibrillation: outcome of radiofrequency vs. cryoballoon pulmonary vein isolation. Europace. 2016 Mar;18(3):368-75. doi: 10.1093/europace/euv271. Epub 2015 Oct 25.
- Derived from this study: PubMed 24994074Straube F, Dorwarth U, Vogt J, Kuniss M, Heinz Kuck K, Tebbenjohanns J, Garcia Alberola A, Chun KR, Souza JJ, Ouarrak T, Senges J, Brachmann J, Lewalter T, Hoffmann E. Differences of two cryoballoon generations: insights from the prospective multicentre, multinational FREEZE Cohort Substudy. Europace. 2014 Oct;16(10):1434-42. doi: 10.1093/europace/euu162. Epub 2014 Jul 3.
- Individual participant dataSharing planned: No. De-identified patient data will be published after end of follow up period
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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.
Ellen Hoffmann, MD principal investigator
Klinikum Bogenhausen, München
37 sites in 6 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Arrhythmia, run by Stiftung Institut fuer Herzinfarktforschung at 37 sites in 6 countries.
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 9 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 27 Jun 2019. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 37 sites in Germany, South Africa, United States, Austria, Greece and 1 more country. 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?
AF recurrency rate (any detected episode lasting > 30 sec) at 12 months follow up (time frame: Admission to hospital until 12 months thereafter). 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 NCT01360008, which also lists 6 linked publications.
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 27 Jun 2019.