title: Atrial fibrillation ablation using a closed irrigation radiofrequency ablation catheter.
abstract: BACKGROUND
  Catheter ablation is an effective therapy for symptomatic, medically refractory atrial fibrillation (AF). Open-irrigated radiofrequency (RF) ablation catheters produce transmural lesions at the cost of increased fluid delivery. In vivo models suggest closed-irrigated RF catheters create equivalent lesions, but clinical outcomes are limited.
  
  
  METHODS
  A cohort of 195 sequential patients with symptomatic AF underwent stepwise AF ablation (AFA) using a closed-irrigation ablation catheter. Recurrence of AF was monitored and outcomes were evaluated using Kaplan-Meier survival analysis and Cox proportional hazards models.
  
  
  RESULTS
  Mean age was 59.0 years, 74.9% were male, 56.4% of patients were paroxysmal and mean duration of AF was 5.4 years. Patients had multiple comorbidities including hypertension (76.4%), tobacco abuse (42.1%), diabetes (17.4%), and obesity (mean body mass index 30.8). The median follow-up was 55.8 weeks. Overall event-free survival was 73.6% with one ablation and 77.4% after reablation (reablation rate was 8.7%). Median time to recurrence was 26.9 weeks. AF was more likely to recur in patients being treated with antiarrhythmic therapy at the time of last follow-up (recurrence rate 30.3% with antiarrhythmic drugs, 13.2% without antiarrhythmic drugs; hazard ratio [HR] 2.2, 95% confidence interval [CI] 1.1-4.4, P = 0.024) and in those with a history of AF greater than 2 years duration (HR 2.7, 95% CI 1.1-6.9, P = 0.038).
  
  
  CONCLUSIONS
  Our study represents the largest cohort of patients receiving AFA with closed-irrigation ablation catheters. We demonstrate comparable outcomes to those previously reported in studies of open-irrigation ablation catheters. Given the theoretical benefits of a closed-irrigation system, a large head-to-head comparison using this catheter is warranted.
authors.affiliation: Department of Cardiology, University of North Carolina, Chapel Hill, North Carolina, USA. goldenk5@gmail.com
authors.forename: Keith
authors.initials: K
authors.lastname: Golden
authors.forename: John Paul
authors.initials: JP
authors.lastname: Mounsey
authors.forename: Eugene
authors.initials: E
authors.lastname: Chung
authors.forename: Pahresah
authors.initials: P
authors.lastname: Roomiani
authors.forename: Michael Andew
authors.initials: MA
authors.lastname: Morse
authors.forename: Ankit
authors.initials: A
authors.lastname: Patel
authors.forename: Anil
authors.initials: A
authors.lastname: Gehi
mesh_terms: D001281:Atrial Fibrillation / Q000453:epidemiology* / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods / Q000706:statistics & numerical data*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009657:North Carolina / Q000453:epidemiology; D015995:Prevalence; D012008:Recurrence; D007507:Therapeutic Irrigation / Q000379:methods / Q000706:statistics & numerical data*; D016896:Treatment Outcome