title: Outcome of paroxysmal atrial fibrillation ablation with the cryoballoon using two different application times: the 4- versus 3-min protocol.
abstract: OBJECTIVE
  The second-generation cryoballoon (CBG2) is highly effective for pulmonary vein isolation (PVI) in paroxysmal atrial fibrillation (PAF). One-year outcome data are consistent among different research groups. First results suggest that a shortened application time might be equally effective. The objective of the study was to compare procedural and outcome data for a 240 and 180-s protocol.
  
  
  METHODS
  Prospectively, consecutive patients with symptomatic PAF underwent initial PVI with CBG2. In succession, two groups were created: the application time was 240 s in group 1 and 180 s in group 2. In both groups, a bonus application was applied. Periprocedural data, complications, and freedom from atrial fibrillation (AF)/AT/symptoms were compared between the groups.
  
  
  RESULTS
  From May 2012 to June 2013, 114 patients (57 per group, 38% female) were included. The mean left atrial dwelling time decreased by 19 min (-16%) in group 2 compared to group 1 (p = 0.005). Intraprocedural pulmonary vein (PV) reconduction occurred infrequently (0.4% in both groups, p = 1.0). One persistent PNP occurred and resolved during the follow-up. Complications were without significant differences. One patient was lost to follow-up. The cumulative rates of freedom from recurrence at 12 months are 76.8% in group 1 and 83.6% in group 2. After a mean follow-up of 491 ± 208 days, the rates of freedom from AF/AT/symptoms at last visit were 38/57 (67%) and 44/56 (78.6%) in groups 1 and 2 (p = 0.14), respectively. Female sex was identified as a predictor for recurrence.
  
  
  CONCLUSIONS
  Compared to a protocol with cryoballoon applications of 240 s, a shortened application time to 180 s results in a faster procedure with comparable high rates of freedom from AF at 16 months. Female sex seems to be predictive for recurrences; this finding has to be reconfirmed in a larger population.
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 and Internal Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich Municipal Hospital Group, Englschalkinger Str. 77, 81925, Munich, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Hartl
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: Benedikt
authors.initials: B
authors.lastname: Bunz
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: Michael
authors.initials: M
authors.lastname: Wankerl
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: Ullrich
authors.initials: U
authors.lastname: Ebersberger
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 / Q000175:diagnosis / Q000453:epidemiology* / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods / Q000706:statistics & numerical data*; D003452:Cryosurgery / Q000379:methods* / Q000706:statistics & numerical data*; D018572:Disease-Free Survival; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D061646:Operative Time; D015995:Prevalence; D012307:Risk Factors; D017678:Sex Distribution; D016896:Treatment Outcome
keywords: Ablation; Application time; Atrial fibrillation; Cryoballoon; Dosing