Design and Baseline Patient Characteristics of the Prospective, Observational, Multicenter and Multinational Cohort Study Comparing Radiofrequency with Cryoablation for Pulmonary Vein Isolation in Patients with Atrial Fibrillation—The Freeze Cohort Study
Ellen Hoffmann1, Uwe Dorwarth1, Karl Heinz Kuck2, Jürgen Vogt3, Malte Kuniss4, Steffen Schneider5, Jürgen Tebbenjohanns6, Kyong Ryul Julian Chun7, Dietrich Andresen8, Stefan Spitzer9, Thorsten Lewalter10, Stephan Willems11, Johannes Brachmann12, Christoph Stellbrink13, Bernhard Rauch5*, Jochen Senges5
1Department of Cardiology, Klinikum Bogenhausen, Munich, Germany.
2Department of Cardiology, Asklepios Klinik St. Georg, Hamburg, Germany.
3Ruhr University Bochum, Bad Oeynhausen, Germany.
4Department of Cardiology, Kerckhoff Klinik, Bad Nauheim, Germany.
5Stiftung Institut für Herzinfarktforschung, Ludwigshafen am Rhein, Germany.
6Klinikum Hildesheim, Hildesheim, Germany.
7Center for Cardiology and Angiology Frankfurt, CCB, Frankfurt am Main, Germany.
8Department of Cardiology, Vivantes Klinikum am Urban, Berlin, Germany.
9Praxisklinik Herz und Gefäße, Dresden, Germany.
10Department of Cardiology, Isar Herzzentrum, Munich, Germany.
11Department of Cardiology, Universitäres Herzzentrum Hamburg, Hamburg, Germany.
12Department of Cardiology, Klinikum Coburg, Coburg, Coburg.
13Department of Cardiology, Klinikum Bielefeld, Bielefeld, Germany.
DOI: 10.4236/ijcm.2014.519149   PDF   HTML     4,585 Downloads   5,557 Views   Citations


Aims: The FREEZE-cohort study (NCT 01360008) is a prospective observational, multicenter and multinational study to evaluate safety and effectiveness of cryoballoon ablation for pulmonary vein isolation as compared to radiofrequency ablation in patients with paroxysmal or persistent atrial fibrillation (lasting < one year) under the conditions of clinical routine. Methods and Results: The study started in 2011 and anticipates inclusion up to 2000 patients in each of the two treatment groups. A total of 37 centers from 8 countries worldwide, all experienced in at least one of the two ablation techniques, participate in the study. The primary outcome parameter of the study is defined as atrial fibrillation recurrence rate during twelve months of follow-up. Secondary outcome parameters include primary success rates, complication rates in general, specific complications with respect to phrenic nerve palsy and pulmonary vein stenosis, radiation exposure, clinical course including death and repeat ablation. Finally specific procedural aspects will be evaluated in a descriptive manner. Preliminary data of the first 1882 patients show that in clinical practice cryoablation is preferentially performed in patients with paroxysmal atrial fibrillation, whereas application of radiofrequency ablation is equally distributed between patients with persistent and paroxysmal atrial fibrillation. Conclusion: Based on multi-center and multi-national data the FREEZE-cohort study will provide important information on long-term efficacy, clinical effectiveness, complication rates and procedural differences between atrial fibrillation patients treated with either cryoablation or radiofrequency ablation.

Share and Cite:

Hoffmann, E. , Dorwarth, U. , Kuck, K. , Vogt, J. , Kuniss, M. , Schneider, S. , Tebbenjohanns, J. , Chun, K. , Andresen, D. , Spitzer, S. , Lewalter, T. , Willems, S. , Brachmann, J. , Stellbrink, C. , Rauch, B. and Senges, J. (2014) Design and Baseline Patient Characteristics of the Prospective, Observational, Multicenter and Multinational Cohort Study Comparing Radiofrequency with Cryoablation for Pulmonary Vein Isolation in Patients with Atrial Fibrillation—The Freeze Cohort Study. International Journal of Clinical Medicine, 5, 1161-1172. doi: 10.4236/ijcm.2014.519149.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Ball, J., Carrington, M.J., McMurray, J.J. and Stewart, S. (2013) Atrial Fibrillation: Profile and Burden of an Evolving Epidemic in the 21st Century. International Journal of Cardiology, 167, 1807-1824.
[2] Haïssaguerre, M., Jaïs, P., Shah, D.C., Takahashi, A., Hocini, M., Quiniou, G., Garrigue, S., Le Mouroux, A., Le Méayer, P. and Clémenty, J. (1998) Spontaneous Initiation of Atrial Fibrillation by Ectopic Beats Originating in the Pulmonary Veins. New England Journal of Medicine, 339, 659-666.
[3] Cappato, R., Calkins, H., Chen, S.A., Davies, W., Iesaka, Y., Kalman, J., Kim, Y.H., Klein, G., Packer, D. and Skanes, A. (2005) Worldwide Survey on the Methods, Efficacy, and Safety of Catheter Ablation for Human Atrial Fibrillation. Circulation, 111, 1100-1105.
[4] Cappato, R., Calkins, H., Chen, S.A., Davies, W., Iesaka, Y., Kalman, J., Kim, Y.H., Klein, G., Natale, A., Packer, D. and Skanes, A. (2009) Prevalence and Causes of Fatal Outcome in Catheter Ablation of Atrial Fibrillation. Journal of the American College of Cardiology, 53, 1798-1803.
[5] Neumann, T., Vogt, J., Schumacher, B., Dorszewski, A., Kuniss, M., Neuser, H., Kurzidim, K., Berkowitsch, A., Koller, M., Heintze, J., Scholz, U., Wetzel, U., Schneider, M.A., Hortskotte, D., Hamm, C. and Pitschner, H.J. (2008) Circumferential Pulmonary Vein Isolation with the Cryoballoon Technique—Results from a Prospective 3-Center Study. Journal of the American College of Cardiology, 52, 273-278.
[6] Chun, K.-R.J., Schmidt, B., Metzner, A., Tilz, R., Zerm, T., Köster, I., Fürnkranz, A., Koektuerk, B., Konstantinidou, M., Antz, M., Ouyang, F. and Kuck, K.H. (2009) The “Single Big Cryoballoon” Technique for Acute Pulmonary Vein Isolation in Patients with Paroxysmal Atrial Fibrillation: A Prospective Observational Single Center Study. European Heart Journal, 30, 699-709.
[7] Malmborg, H., Lönnerholm, S. and Blomström-Lundqvist, C. (2008) Acute and Clinical Effects of Cryoballoon Pulmonary Vein Isolation in Patients with Symptomatic Paroxysmal and Persistent Atrial Fibrillation. Europace, 10, 1277-1280.
[8] Kojodjojo, P., O’Neill, M.D., Lim, P.B., Malcolm-Lawes, L., Whinnett, Z.I., Salukhe, T.V., Linton, N.W., Lefroy, D., Mason, A., Wright, I., Peters, N.S., Kanagaratnam, P. and Davies, D.W. (2010) Pulmonary Venous Isolation by Antral Ablation with a Large Cryoballoon for Treatment of Paroxysmal and Persistent Atrial Fibrillation: Medium-Term Outcomes and Non-Randomised Comparison with Pulmonary Venous Isolation by Radiofrequency Ablation. Heart, 96, 1379-1384.
[9] Vogt, J., Heintze, J., Gutleben, K.J., Muntean, B., Horstkotte, D. and Nölker, G. (2013) Long-Term Outcomes after Cryoballoon Pulmonary Vein Isolation. Journal of the American College of Cardiology, 61, 1707-1712.
[10] Packer, D.L., Kowal, R.C., Wheelan, K.R., Irwin, J.M., Champagne, J., Guerra, P.G., Dubuc, M., Reddy, V., Nelson, L., Holcomb, R.G., Lehmann, J.W. and Ruskin, J.N., for the STOP AF Cryoablation Investigators (2013) Cryoballoon Ablation of Pulmonary Veins for Paroxysmal Atrial Fibrillation. Journal of the American College of Cardiology, 61, 1713-1723.
[11] Schmidt, M., Dorwarth, U., Andresen, D., Brachmann, J., Kuck, K.H., Kuniss, M., Lewalter, T., Spitzer, S., Willems, S., Senges, J., Jünger, C. and Hoffmann, E. (2013) Cryoballoon versus RF Ablation in Paroxysmal Atrial Fibrillation: Results from the German Ablation Registry. Journal of Cardiovascular Electrophysiology, 25, 1-7.
[12] Bordignon, S., Chun, K.R.J., Gunawardene, M., Fuernkranz, A., Urban, V., Schulte-Hahn, B., Nowak, B. and Schmidt, B. (2013) Comparison of Balloon Catheter Ablation Technologies for Pulmonary Vein Isolation: The Laser versus Cryo Study. Journal of Cardiovascular Electrophysiology, 24, 987-994.
[13] Pokushalov, E., Romanov, A., Artyomenko, S., Baranova, V., Losik, D., Bairamova, S., Karaskov, A., Mittal, S. and Steinberg, J. (2013) Cryoballoon versus Radiofrequency for Pulmonary Vein Re-Isolation after a Failed Initial Ablation Procedure in Patients with Paroxysmal Atrial Fibrillation. Journal of Cardiovascular Electrophysiology, 24, 274-279.
[14] Malmborg, H., Lönnerholm, S., Blomström, P. and Blomström-Lundqvist, C. (2013) Ablation of Atrial Fibrillation with Cryoballoon or Duty-Cycled Radiofrequency Pulmonary Vein Ablation Catheter: A Randomized Controlled Study Comparing the Clinical Outcome and Safety; the AF-COR Study. Europace, 15, 1567-1573.
[15] Pérez-Castellano, N., Fernández-Cavazos, R., Moreno, J., Canadas, V., Conde, A., González-Ferrer, J.J., Macaya, C. and Pérez-Villacastín, J. (2014) The COR Trial: A Randomized Study with Continuous Rhythm Monitoring to Compare the Efficacy of Cryoenergy and Radiofrequency for Pulmonary Vein Isolation. Heart Rhythm, 11, 8-14.
[16] FIRE and ICE Trial (2014) A Controlled, Prospective, Non-Inferiority, Parallel-Group, Randomized, Interventional, Open, Blinded Outcome Assessment, Multi-Center Trial, Comparing Efficacy and Safety of Isolation of the Pulmonary Veins with a Cryoballoon Catheter versus a Radiofrequency Ablation with a ThermoCool Catheter in Patients with Paroxysmal Atrial Fibrillation. Identifier NCT01490814.
[17] Raviele, A., Natale, A., Calkins, H., Camm, J.A., Cappato, R., Ann Chen, S., Connolly, S.J., Damiano Jr., R., De Ponti, R., Edgerton, J.R., Haïssaguerre, M., Hindricks, G., Ho, S.Y., Jalife, J., Kirchhof, P., Kottkamp, H., Kuck, K.H., Marchlinski, F.E., Packer, D.L., Pappone, C., Prystowsky, E., Reddy, V.K., Themistoclakis, S., Verma, A., Wilber, D.J. and Willems, S. (2012) Venice Chart International Consensus Document on Atrial Fibrillation Ablation: 2011 Update. Journal of Cardiovascular Electrophysiology, 23, 890-923.
[18] Calkins, H., Kuck, K.H., Brugada, J., Cappato, R., Camm, A.J., Chen, S.A., et al. (2012) 2012 HRS/EHRA/ECAS Expert Consensus Statement on Catheter and Surgical Ablation of Atrial Fibrillation: Recommendations for Patient Selection, Procedural Techniques, Patient Management and Follow-Up, Definitions, Endpoints, and Research Trial Design. Heart Rhythm, 9, 632-696.
[19] Camm, A.J., Lip, G.Y.H., De Caterina, R., Savelieva, I., Atar, D., Hohnloser, S.H., Hindricks, G., Kirchhof, P., et al. (2012) 2012 Focused Update of the ESC Guidelines for Management of Atrial Fibrillation: An Update of the 2010 ESC Guidelines for the Management of Atrial Fibrillation. Development with the Special Contribution of the European Heart Rhythm Association. European Heart Journal, 33, 2719-2747.
[20] Kühne, M., Suter, Y., Altmann, D., Ammann, P., Schaer, B., Osswald, S. and Sticherling, C. (2010) Cryoballoon versus Radiofrequency Catheter Ablation of Paroxysmal Atrial Fibrillation: Biomarkers of Myocardial Injury, Recurrence Rates, and Pulmonary Vein Reconnection Patterns. Heart Rhythm, 7, 1770-1776.
[21] Tse, H.F., Reek, S., Timmermans, C., Lee, K.L., Geller, J.C., Rodriquez, L.M., Ghaye, B., Ayers, G.M., Crijns, H.J., Klein, H.U. and Lau, C.P. (2003) Pulmonary Vein Isolation Using Transvenous Catheter Cryoablation for Treatment of Atrial Fibrillation without Risk of Pulmonary Vein Stenosis. Journal of the American College of Cardiology, 42, 752-758.
[22] Schmidt, B., Antz, M., Ernst, S., Ouyang, F., Falk, P., Chun, J.K. and Kuck, K.H. (2007) Pulmonary Vein Isolation by High Intensity Ultrasound: First-in-Man Study with a Steerable Balloon Catheter. Heart Rhythm, 4, 575-584.
[23] Guiot, A., Savouré, A., Godin, B. and Anselme, F. (2012) Collateral Nervous Damages after Cryoballoon Pulmonary Vein Isolation. Journal of Cardiovascular Electrophysiology, 23, 346-351.
[24] Van Belle, Y., Janse, P., Theuns, D., Szili-Torok, T. and Jordaens, L. (2008) One Year Follow-Up after Cryoballoon Isolation of the Pulmonary Veins in Patients with Paroxysmal Atrial Fibrillation. Europace, 10, 1271-1276.
[25] Linhart, M., Bellmann, B., Mittmann-Braun, E., Schrickel, J.W., Bitzen, A., Andrié, R., Yang, A., Nickenig, G., Lickfett, L. and Lewalter, T. (2009) Comparison of Cryoballoon and Radiofrequency Ablation of Pulmonary Veins in 40 Patients with Paroxysmal Atrial Fibrillation: A Case Control Study. Journal of Cardiovascular Electrophysiology, 20, 1343-1348.
[26] Nieuwlaat, R., Capucci, A., Camm, A.J., Olsson, S.B., Andresen, D., Davies, D.W., Cobbe, S., Breithardt, G., Le Heuzey, J.Y., Prins, M.H., Lévy, S. and Crijns, H.J., on Behalf of the Euro Heart Survey Investigators (2005) Atrial Fibrillation Management: A Prospective Survey in ESC Member Countries: The Euro Heart Survey on Atrial Fibrillation. European Heart Journal, 26, 2422-2434.

Copyright © 2022 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.