title: Clinical outcomes of catheter substrate ablation for high-risk patients with atrial fibrillation.
abstract: OBJECTIVE
  The purpose of this study was to determine the long-term clinical outcomes of catheter ablation of atrial fibrillation (AF) substrate for high-risk patients with AF.
  
  
  BACKGROUND
  The benefits of catheter ablation for high-risk AF patients with respect to mortality and stroke reductions remain unclear.
  
  
  METHODS
  We performed AF substrate ablation guided by complex fractionated atrial electrogram (CFAE) mapping in 674 high-risk AF patients. The clinical end points were sinus rhythm (SR), death, stroke, or bleeding. Of these 674 patients, 635 were available for follow-up and made up the study cohort. The patients were relatively old (mean age 67 +/- 12 years) and 129 had an ejection fraction (EF) <40%.
  
  
  RESULTS
  After the mean follow-up period of 836 +/- 605 days, 517 were in SR (81.4%). There were 15 deaths among the patients who stayed in SR compared with 14 deaths among those who remained in AF (5-year survival rate, 92% vs. 64%, respectively; p < 0.0001). SR was the most important independent favorable parameter for survival (hazard ratio 0.14, 95% confidence interval 0.06 to 0.36, p < 0.0001), whereas old age was unfavorable. Warfarin therapy was discontinued in 434 of the 517 patients in SR post-ablation (84%) whose annual stroke rate was only 0.4% compared with 2% in those with continuing warfarin treatment (p = 0.004).
  
  
  CONCLUSIONS
  CFAE-targeted ablation of AF is effective in maintaining SR in selected high-risk AF patients and might allow patients to stop warfarin therapy. SR after AF ablation is a marker of relatively low mortality and stroke risk. Our findings support conducting further randomized studies to determine whether AF ablation is associated with mortality and/or stroke reduction.
authors.affiliation: Pacific Rim Electrophysiology Research Institution, Inglewood, California 90301, USA. wee@pacificrimep.com
authors.forename: Koonlawee
authors.initials: K
authors.lastname: Nademanee
authors.forename: Mark C
authors.initials: MC
authors.lastname: Schwab
authors.forename: Erol M
authors.initials: EM
authors.lastname: Kosar
authors.forename: Margaret
authors.initials: M
authors.lastname: Karwecki
authors.forename: Michael D
authors.initials: MD
authors.lastname: Moran
authors.forename: Nithi
authors.initials: N
authors.lastname: Visessook
authors.forename: Anthony Don
authors.initials: AD
authors.lastname: Michael
authors.forename: Tachapong
authors.initials: T
authors.lastname: Ngarmukos
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000150:complications / Q000401:mortality / Q000601:surgery*; D017115:Catheter Ablation; D005260:Female; D006801:Humans; D008297:Male; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology / Q000209:etiology; D013997:Time Factors; D016896:Treatment Outcome