Author(s)

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 Rauch^5*, 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.

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.

Atrial Fibrillation, Catheter Ablation, Cryoballoon Ablation, Radiofrequency Ablation, Registry

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.