title: Differences of two cryoballoon generations: insights from the prospective multicentre, multinational FREEZE Cohort Substudy.
abstract: OBJECTIVE
  Cryoballoon (CB) ablation with the second-generation cryoballoon (CBG2) seems to be more effective than its predecessor [first-generation cryoballoon (CBG1)], but phrenic nerve palsies were observed more frequently. The aim of this study was to compare the safety and efficacy of CBG1 and CBG2 in a substudy of the prospective multicentre, multinational FREEZE Cohort Study.
  
  
  RESULTS
  Periprocedural data were analysed, and a total of 532 patients with paroxysmal atrial fibrillation (AF) were examined (n = 224 for CBG1 and n = 308 for CBG2). Procedure time decreased significantly from 149 to 130 min when comparing CBG1 with CBG2 (P < 0.0001), and pulmonary vein isolation (PVI) was achieved in 97.8 and 97.6% of PVs with CBG1 and CBG2 (P = 0.77), respectively. The need for dual-balloon usage within a procedure dropped (20.1 vs. 9.0%, P < 0.001), and the fluoroscopy time was reduced when operating the CBG2. Atrial fibrillation recurrence rates until discharge were similar (5.0 vs. 5.8%, P = 0.69). Comparable low rates of major complications were observed with both CBs, and there was a non-significant trend for more phrenic nerve palsies.
  
  
  CONCLUSIONS
  Second-generation cryoballoon demonstrated a high rate of acute PVI in a significant faster procedure, which also utilized less radiation exposure and less dual-balloon usage during an average procedure. The safety profile remains favourable with a non-significant trend for more phrenic nerve palsies. If the enhancements lead to a higher clinical benefit has to be determined. The 1-year outcome data from the ongoing FREEZE Cohort Study comparing radiofrequency and CB ablation will shed some light on that issue.
  NCT01360008.
authors.affiliation: Department of Cardiology and Internal Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich Municipal Hospital Group, Englschalkinger Str. 77, 81925 Munich, Germany florian.straube@klinikum-muenchen.de.
authors.forename: Florian
authors.initials: F
authors.lastname: Straube
authors.affiliation: Department of Cardiology and Internal Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich Municipal Hospital Group, Englschalkinger Str. 77, 81925 Munich, Germany.
authors.forename: Uwe
authors.initials: U
authors.lastname: Dorwarth
authors.affiliation: Department of Cardiology, Heart and Diabetes Center North Rhine-Westphalia, Ruhr University Bochum, 32545 Bad Oeynhausen, Germany.
authors.forename: Juergen
authors.initials: J
authors.lastname: Vogt
authors.affiliation: Kerckhoff-Klinik GmbH, Department of Cardiology, 61231 Bad Nauheim, Germany.
authors.forename: Malte
authors.initials: M
authors.lastname: Kuniss
authors.affiliation: Asklepios St Georg Hospital, Department of Cardiology, 20009 Hamburg, Germany.
authors.forename: Karl
authors.initials: K
authors.lastname: Heinz Kuck
authors.affiliation: Klinikum Hildesheim, Department of Cardiology, 31115 Hildesheim, Germany.
authors.forename: Juergen
authors.initials: J
authors.lastname: Tebbenjohanns
authors.affiliation: University Hospital Virgen de la Arrixaca, Department of Cardiology, 30120 El Palmar, Murcia, Spain.
authors.forename: Arcadi
authors.initials: A
authors.lastname: Garcia Alberola
authors.affiliation: Cardioangiologisches Centrum Bethanien, CCB, Department of Cardiology, 60431 Frankfurt a.M., Germany.
authors.forename: Kyoung Ryul Julian
authors.initials: KR
authors.lastname: Chun
authors.affiliation: Mission Hospital, Inc., Department of Cardiology, 28801 Asheville, NC, USA.
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Souza
authors.affiliation: Institut fuer Herzinfarktforschung, IHF Foundation, 67063 Ludwigshafen, Germany.
authors.forename: Taoufik
authors.initials: T
authors.lastname: Ouarrak
authors.affiliation: Institut fuer Herzinfarktforschung, IHF Foundation, 67063 Ludwigshafen, Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Senges
authors.affiliation: Klinikum Coburg, Department of Cardiology, 96450 Coburg, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Brachmann
authors.affiliation: Department of Cardiology, Isar Herz Center Munich, Munich, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Lewalter
authors.affiliation: Department of Cardiology and Internal Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich Municipal Hospital Group, Englschalkinger Str. 77, 81925 Munich, Germany.
authors.forename: Ellen
authors.initials: E
authors.lastname: Hoffmann
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D003452:Cryosurgery / Q000295:instrumentation*; D004452:Echocardiography; D005260:Female; D005471:Fluoroscopy; D006801:Humans; D008297:Male; D008875:Middle Aged; D061646:Operative Time; D061214:Patient Safety; D011183:Postoperative Complications; D011446:Prospective Studies; D011667:Pulmonary Veins / Q000601:surgery; D016896:Treatment Outcome
keywords: Ablation; Atrial fibrillation; Cryoballoon; Efficacy; Pulmonary vein isolation; Safety