title: Left atrial volume is more important than the type of atrial fibrillation in predicting the long-term success of catheter ablation.
abstract: BACKGROUND
  The type of atrial fibrillation (AF) is the sole prognostic factor that affects the level of recommendation for catheter ablation in the current guidelines. Despite being recognized as a predictor of recurrence, relatively little emphasis is given to left atrium (LA) size. The aim of this study was to assess the relative importance of LA volume and type of AF as predictors of outcome after PVI.
  
  
  METHODS
  We assessed 809 consecutive patients with symptomatic drug-refractory AF (584 male, mean age 57 ± 11 years) undergoing 905 percutaneous PVI procedures in two centers. LA volume was assessed by cardiac CT and/or electroanatomical mapping prior to AF ablation. The study endpoint was symptomatic and/or documented AF recurrence.
  
  
  RESULTS
  The majority of patients (73.2%, n=592) had paroxysmal AF. The mean indexed LA volume was 55 ± 20 ml/m(2). During a follow-up of 2.4 ± 1.7 years, there were 280 recurrences. The relapse rate of patients with paroxysmal AF in the highest tertile of LA volume was higher than the relapse rate of patients with non-paroxysmal AF in the lowest tertile (20.0% vs. 10.9% per person-year, respectively, p=0.041). LA volume (HR 1.16 for each 10 ml/m(2), 95% CI 1.09-1.23, p<0.001), female gender (HR 1.55, 95% CI 1.19-2.03, p=0.001), and non-paroxysmal AF (HR 1.31, 95% CI 1.01-1.69, p=0.039) were the only independent predictors of AF recurrence. Split-sample cross-validation resampling confirmed LA volume as the strongest predictor of relapse after PVI.
  
  
  CONCLUSIONS
  Left atrial volume seems to be more important than the type of atrial fibrillation in predicting the long-term success of pulmonary vein isolation.
authors.affiliation: Cardiology Department, Arrhythmia Unit, Hospital Santa Cruz, Western Lisbon Hospital Center, Portugal; Heart Rhythm Center, Hospital da Luz, Lisbon, Portugal. Electronic address: fmoscosocosta@gmail.com.
authors.forename: Francisco Moscoso
authors.initials: FM
authors.lastname: Costa
authors.affiliation: Cardiology Department, Arrhythmia Unit, Hospital Santa Cruz, Western Lisbon Hospital Center, Portugal; Cardiovascular Imaging Unit, Hospital da Luz, Lisbon, Portugal.
authors.forename: António Miguel
authors.initials: AM
authors.lastname: Ferreira
authors.affiliation: Cardiology Department, Arrhythmia Unit, Hospital Santa Cruz, Western Lisbon Hospital Center, Portugal.
authors.forename: Sílvia
authors.initials: S
authors.lastname: Oliveira
authors.affiliation: Cardiology Department, Arrhythmia Unit, Hospital Santa Cruz, Western Lisbon Hospital Center, Portugal; Heart Rhythm Center, Hospital da Luz, Lisbon, Portugal.
authors.forename: Pedro Galvão
authors.initials: PG
authors.lastname: Santos
authors.affiliation: Cardiology Department, Arrhythmia Unit, Hospital Santa Cruz, Western Lisbon Hospital Center, Portugal.
authors.forename: Anai
authors.initials: A
authors.lastname: Durazzo
authors.affiliation: Cardiology Department, Arrhythmia Unit, Hospital Santa Cruz, Western Lisbon Hospital Center, Portugal; Heart Rhythm Center, Hospital da Luz, Lisbon, Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Carmo
authors.affiliation: Heart Rhythm Center, Hospital da Luz, Lisbon, Portugal.
authors.forename: Katya Reis
authors.initials: KR
authors.lastname: Santos
authors.affiliation: Cardiology Department, Arrhythmia Unit, Hospital Santa Cruz, Western Lisbon Hospital Center, Portugal; Heart Rhythm Center, Hospital da Luz, Lisbon, Portugal.
authors.forename: Diogo
authors.initials: D
authors.lastname: Cavaco
authors.affiliation: Heart Rhythm Center, Hospital da Luz, Lisbon, Portugal.
authors.forename: Leonor
authors.initials: L
authors.lastname: Parreira
authors.affiliation: Cardiology Department, Arrhythmia Unit, Hospital Santa Cruz, Western Lisbon Hospital Center, Portugal.
authors.forename: Francisco
authors.initials: F
authors.lastname: Morgado
authors.affiliation: Cardiology Department, Arrhythmia Unit, Hospital Santa Cruz, Western Lisbon Hospital Center, Portugal; Heart Rhythm Center, Hospital da Luz, Lisbon, Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Adragão
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging* / Q000401:mortality / Q000601:surgery*; D017115:Catheter Ablation / Q000401:mortality / Q000639:trends*; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000000981:diagnostic imaging* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000401:mortality / Q000639:trends; D009929:Organ Size; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012042:Registries; D013997:Time Factors; D016896:Treatment Outcome
keywords: Atrial fibrillation; Cardiac computed tomography; Catheter ablation; Left atrium; Prognosis; Pulmonary vein isolation