title: The impact of age on the electroanatomical characteristics and outcome of catheter ablation in patients with atrial fibrillation.
abstract: BACKGROUND
  Previous studies have indicated that atrial fibrillation (AF) in patients over the age of 60 at diagnosis is a risk factor for a substantial increase in cardiovascular events. However, information about the impact of age on the atrial substrate and clinical outcome after catheter ablation of AF is limited.
  
  
  METHODS
  This study included 350 patients (53 ± 12 years, 254 males) who underwent circumferential pulmonary vein isolation (CPVI) of AF, guided by a NavX mapping system. The subjects were divided into three groups according to their age, as follows: Group I: age ≤50 (n = 141), Group II: age = 51-64 (n = 149) and Group III: age ≥65 years old (n = 60). The mean voltage and total activation time of the individual atria were obtained by using a NavX mapping system before ablation. Several parameters, including the gender, AF duration, and left atrial (LA) diameter were analyzed.
  
  
  RESULTS
  The younger age group had a significantly smaller LA diameter (Group I vs Group II vs Group III, 36.89 ± 7.11 vs 39.16 ± 5.65 vs 40.77 ± 4.95 mm, P = 0.002) and higher LA bipolar voltage (2.09 ± 0.83 vs 1.73 ± 0.73 vs 1.86 ± 0.67 mV, respectively, P = 0.024), compared with the older AF patients. The LA bipolar voltage exhibited a significant reduction when the patients became older, however, that did not occur in the right atrium. The incidence of an AF recurrence was higher in the older age group than in the younger age groups. A subgroup of patients with lone AF was analyzed and age was found to be an independent predictor of the AF recurrence after receiving the first CPVI in the multivariable model (P < 0.05).
  
  
  CONCLUSIONS
  Age has a significant impact on the LA substrate properties and outcome of the catheter ablation of AF.
authors.affiliation: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, R.O.C.
authors.forename: Ta-Chuan
authors.initials: TC
authors.lastname: Tuan
authors.forename: Shih-Lin
authors.initials: SL
authors.lastname: Chang
authors.forename: Hsuan-Ming
authors.initials: HM
authors.lastname: Tsao
authors.forename: Ching-Tai
authors.initials: CT
authors.lastname: Tai
authors.forename: Yenn-Jiang
authors.initials: YJ
authors.lastname: Lin
authors.forename: Yu-Feng
authors.initials: YF
authors.lastname: Hu
authors.forename: Li-Wei
authors.initials: LW
authors.lastname: Lo
authors.forename: Ameya R
authors.initials: AR
authors.lastname: Udyavar
authors.forename: Chien-Jong
authors.initials: CJ
authors.lastname: Chang
authors.forename: Wen-Chin
authors.initials: WC
authors.lastname: Tsai
authors.forename: Wei-Hua
authors.initials: WH
authors.lastname: Tang
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Suenari
authors.forename: Shih-Yu
authors.initials: SY
authors.lastname: Huang
authors.forename: Pi-Change
authors.initials: PC
authors.lastname: Lee
authors.forename: Shih-Ann
authors.initials: SA
authors.lastname: Chen
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001281:Atrial Fibrillation / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects; D016009:Chi-Square Distribution; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins / Q000503:physiopathology / Q000601:surgery*; D012008:Recurrence; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013624:Taiwan; D016896:Treatment Outcome