Now Available: Final Rule for FDAAA 801 and NIH Policy on Clinical Trial Reporting

FREEZE Cohort Study

This study is ongoing, but not recruiting participants.
Information provided by (Responsible Party):
Stiftung Institut fuer Herzinfarktforschung Identifier:
First received: May 13, 2011
Last updated: June 16, 2016
Last verified: June 2016
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.


Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: FREEZE Cohort Study

Further study details as provided by Stiftung Institut fuer Herzinfarktforschung:

Primary Outcome Measures:
  • AF recurrency rate (any detected episode lasting > 30 sec) at 12 months follow up [ Time Frame: Admission to hospital until 12 months thereafter ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Comparison of complication rates (any complications and major complications) at 12 months follow-up [ Time Frame: Admission to hospital until 12 months thereafter ] [ Designated as safety issue: Yes ]
  • Specific complication aspects with respect to phrenic nerve palsy and PV stenosis [ Time Frame: Admission to Hospital until 12 months thereafter ] [ Designated as safety issue: Yes ]
  • 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 ] [ Designated as safety issue: No ]
  • Persistent AF: Impact on efficacy analyzing procedural aspects in cryoballoon PVI [ Time Frame: Admission to Hospital until 12 months thereafter ] [ Designated as safety issue: No ]
  • 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 ] [ Designated as safety issue: No ]

Enrollment: 4071
Study Start Date: April 2011
Estimated Study Completion Date: April 2017
Primary Completion Date: January 2016 (Final data collection date for primary outcome measure)
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

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.

Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
Patients with AF ablation targeting

Inclusion Criteria:

  • 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

Exclusion Criteria:

  • 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
  • Uncontrolled hyperthyroidism
  • Pregnancy
  • Life expectancy < 1 year
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01360008

United States, North Carolina
Mission Hospital, Inc.
Asheville, North Carolina, United States, 28803
Allgemeines KH Linz
Linz, Austria, 4020
Klinikum Aschaffenburg
Aschaffenburg, Germany, 63739
Herz-Zentrum Bad Krozingen
Bad Krozingen, Germany
Bad Nauheim, Germany
Herz- und Gefäßklinik Bad Neustadt; Klinik für Kardiologie II
Bad Neustadt, Germany, 97616
Herz- und Diabeteszentrum
Bad Oeynhausen, Germany
Deutsches Herzzentrum Berlin (Kardiologie)
Berlin, Germany, 13353
Vivantes Klinikum Am Urban
Berlin, Germany
Klinikum Bielelfeld - Klinik für Kardiologie und internistische Intensivmedizin
Bielefeld, Germany, 33604
Universitätsklinikum Bonn (Med. Klinik und Poliklinik II)
Bonn, Germany, 53105
Klinikum Coburg
Coburg, Germany
Praxisklinik Herz und Gefäße
Dresden, Germany
Elisabeth-Krankenhaus Essen; Klinik für Kardiologie und Angiologie
Essen, Germany, 45138
Städt. Klinikum Frankfurt Höchst
Frankfurt, Germany, 65929
Cardioangiologisches Centrum Bethanien - CCB
Frankfurt, Germany
Universitäres Herzzentrum Eppendorf
Hamburg, Germany, 20246
Asklepios Klinik St. Georg
Hamburg, Germany
Universitäres Herzzentrum
Hamburg, Germany
Klinikum Siloah
Hannover, Germany, 30449
Universitätsklinikum Heidelberg
Heidelberg, Germany, 69120
Städt. Klinikum Hildesheim
Hildesheim, Germany
Klinikum Ingolstadt
Ingolstadt, Germany, 85049
Westpfalz-Klinikum GmbH
Kaiserslautern, Germany
St. Vinzenz Hospital Köln-Nippes
Köln, Germany, 50733
Universitätsklinik Schleswig-Holstein Campus Lübeck
Lübeck, Germany, 23538
Universitätsmedizin Mainz
Mainz, Germany, 55131
Isar Herzzentrum München
München, Germany
Krankenhaus München Bogenhausen
München, Germany
Universitätsklinikum Münster
Münster, Germany
Klinikum Traunstein
Traunstein, Germany, 83278
Schwarzwald-Baar-Klinikum Villingen-Schwenningen GmbH
Villingen-Schwenningen, Germany, 78052
Evangelismos General Hospital
Athens, Greece, 106 76
South Africa
Sunninghill Hospital
Johannesburg, South Africa, 2196
Panorama Medi-Clinic
Panorama, South Africa, 7500
Milpark Hospital
Parktown West, South Africa, 2193
University Hospital Virgen de la Arrixaca
El Palmar - Murcia, Spain, 30120
Sponsors and Collaborators
Stiftung Institut fuer Herzinfarktforschung
Principal Investigator: Ellen Hoffmann, MD Klinikum Bogenhausen, München
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Stiftung Institut fuer Herzinfarktforschung Identifier: NCT01360008     History of Changes
Other Study ID Numbers: FREEZE 
Study First Received: May 13, 2011
Last Updated: June 16, 2016
Health Authority: Germany: Ethics Commission
Individual Participant Data  
Plan to Share IPD: Yes
Plan Description: De-identified patient data will be published after end of follow up period

Keywords provided by Stiftung Institut fuer Herzinfarktforschung:
Cardiac arrhythmia
Catheter ablation
Cohort Study
radiofrequency processed this record on October 27, 2016