title: A prospective and randomized comparison of limited versus extensive atrial substrate modification after circumferential pulmonary vein isolation in nonparoxysmal atrial fibrillation.
abstract: BACKGROUND
  The optimal substrate ablation approach in patients with persistent atrial fibrillation (Per AF) remains unclear. This was a prospective randomized study comparing the efficacy of limited (continuous complex fractionated atrial electrogram, CFAE: <60 milliseconds) versus extensive (continuous CFAE plus variable CFAE: <120 milliseconds) atrial substrate modification in Per AF patients.
  
  
  RESULTS
  We enrolled 120 Per AF patients in the study, and 30 patients with AF termination after pulmonary vein isolation (PVI) were excluded. In the remaining 90 patients, 45 were treated with limited approach (Group 1) and 45 with an extensive approach (Group 2). The end point of the study was the incidence of an atrial arrhythmia recurrence postblanking period. The patients were followed up for 15 months with 3-month clinical reviews, electrograms (ECGs), Holter recordings, and echocardiographic monitoring. Procedural AF termination and the single procedural efficacy were statistically comparable between the 2 groups (48.9% vs. 63.4% in Groups 1 and 2, respectively, P = 0.289). During the follow-up, patients who received limited ablation had a lower incidence of recurrent AFL (P = 0.04), and better reverse remodeling of the left atrium (LA, P = 0.04). After 2 procedures, the freedom from any atrial arrhythmia was better in Group 2 (62.2% vs. 87.8%, P = 0.009). Those with longstanding AF and a larger baseline LA size responded better to the extensive ablation.
  
  
  CONCLUSIONS
  In the Per AF patients who failed to achieve AF termination after PVI alone, a specific atrial substrate modification approach targeting only continuous CFAEs could be considered as an initial ablation strategy.
authors.affiliation: Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan.|Faculty of Medicine, Institute of Clinical Medicine, and Cardiovascular Research Institute, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Yenn-Jiang
authors.initials: YJ
authors.lastname: Lin
authors.affiliation: Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan.|Faculty of Medicine, Institute of Clinical Medicine, and Cardiovascular Research Institute, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Shih-Lin
authors.initials: SL
authors.lastname: Chang
authors.affiliation: Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan.|Faculty of Medicine, Institute of Clinical Medicine, and Cardiovascular Research Institute, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Li-Wei
authors.initials: LW
authors.lastname: Lo
authors.affiliation: Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan.|Faculty of Medicine, Institute of Clinical Medicine, and Cardiovascular Research Institute, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Yu-Feng
authors.initials: YF
authors.lastname: Hu
authors.affiliation: Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan.|Faculty of Medicine, Institute of Clinical Medicine, and Cardiovascular Research Institute, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Eric
authors.initials: E
authors.lastname: Chong
authors.affiliation: Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan.|Faculty of Medicine, Institute of Clinical Medicine, and Cardiovascular Research Institute, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Tze-Fan
authors.initials: TF
authors.lastname: Chao
authors.affiliation: Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Fa-Po
authors.initials: FP
authors.lastname: Chung
authors.affiliation: Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Jonan
authors.initials: J
authors.lastname: Liao
authors.affiliation: Cardiovascular Center, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Cheng-Hung
authors.initials: CH
authors.lastname: Li
authors.affiliation: Cardiology, National Yang Ming University Hospital, I-Lan, Taiwan.
authors.forename: Hsuan-Ming
authors.initials: HM
authors.lastname: Tsao
authors.affiliation: Department of Biomedical Engineering, Hungkuang University, Taichung, Taiwan.
authors.forename: Tsair
authors.initials: T
authors.lastname: Kao
authors.affiliation: Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Yun-Yu
authors.initials: YY
authors.lastname: Chen
authors.affiliation: Faculty of Medicine, Institute of Clinical Medicine, and Cardiovascular Research Institute, National Yang-Ming University, Taipei, Taiwan.|Cardiovascular Center, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Jin-Long
authors.initials: JL
authors.lastname: Huang
authors.affiliation: Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan.|Faculty of Medicine, Institute of Clinical Medicine, and Cardiovascular Research Institute, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Shih-Ann
authors.initials: SA
authors.lastname: Chen
mesh_terms: D000328:Adult; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects / Q000379:methods*; D015150:Echocardiography, Doppler; D017548:Echocardiography, Transesophageal; D015716:Electrocardiography, Ambulatory; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011667:Pulmonary Veins / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D012008:Recurrence; D013624:Taiwan; D013997:Time Factors; D016896:Treatment Outcome
keywords: atrial fibrillation; atrial substrate; catheter ablation; complex fractionated atrial electrograms; electrogram; pulmonary vein isolation