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

Abstract

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.

Outcomes of cryoballoon or radiofrequency ablation in symptomatic paroxysmal or persistent atrial fibrillation

“…The present study was a prospective multicentre and multinational observational cluster cohort study to compare the effectiveness and safety of either RFA or CBA in the initial ablation procedure in patients with AF 8 , 9 . The cluster design of the study was adopted to compare the characteristics, procedural results, and outcomes of patients treated in experienced CBA centres with those treated in experienced RFA centres.…”

Cryoballoon ablation for persistent atrial fibrillation – Large single-center experience

“…Only a limited number of patients were investigated. The ongoing Freeze Cohort Study [18] (NCT01360008), including a total of 4000 patients with paroxysmal or persistent AF undergoing CB or RF ablation, will give more answers to the question of the preferred technique to perform a safe and effective AF ablation.…”

Electrophysiology lab efficiency comparison between cryoballoon and point-by-point radiofrequency ablation: a German sub-analysis of the FREEZE Cohort study

“…The FREEZE Cohort study (NCT01360008) was a prospective, non-randomized, observational cluster cohort study that compared the effectiveness and safety of RFA and CBA, conducted in 42 experienced hospitals across eight countries [ 5 ]. Each centre was assigned as a RFA or a CBA study site, chosen according to the centre’s experience and preference.…”