title: Atrial structure and function 5 years after successful ablation for persistent atrial fibrillation: an MRI study.
abstract: BACKGROUND
  The atrial outcome after extensive ablation is unknown. We sought to quantify atrial structure and function years after successful ablation for persistent atrial fibrillation (PsAF).
  
  
  RESULTS
  We studied after 80 ± 15 months 26 patients (54 ± 8 years, 1 woman) with PsAF successfully treated by ablation (2.2 ± 0.7 stepwise approach procedures, cumulative RF duration 126 ± 37 minutes). At follow-up atrial scar burden and atrial outflows were quantified using delayed-enhanced and velocity-encoded MRI, respectively. Cine imaging was used to quantify atrial conduit function (CF), active emptying fraction (AEF), expansion index (EI), and the inter-appendage mechanical activation delay. Patients underwent exercise testing at baseline and follow-up. LA and RA scar extent were 29 ± 6 and 4.3 ± 2.8%, respectively. LA and RA AEF were 10.0 ± 5.3 and 30 ± 8%. Mean inter-appendage delay was 83 ± 47 ms [42-217]. Complete LAA isolation was found in 3 patients. A wave was absent in 9/26 patients. LA scar extent related to the number of procedures (R = 0.58, P = 0.002) and total RF duration (R = 0.56, P = 0.003). Among follow-up characteristics, LA scar extent related to LAAEF (R = -0.73, P < 0.0001), LAEI (R = -0.64, P = 0.0003), A-wave peak (R = -0.72, P < 0.0001), and inter-appendage mechanical delay (R = 0.47, P = 0.02). At multivariable analysis, LA scar extent was independently related to LAAEF and LAEI. LAAEF and LA scar extent correlated with exercise capacity at follow-up (R = 0.44, P = 0.02, and R = -0.40; P = 0.04).
  
  
  CONCLUSIONS
  LA contractility and compliance are markedly impaired years after successful PsAF ablation. LA dysfunction is closely related to scar burden.
authors.affiliation: Department of Cardiovascular Imaging, CHU / Université de Bordeaux, Pessac, France; L'Institut de Rythmologie et de Modélisation Cardiaque LIRYC, CHU / Université de Bordeaux / INSERM U1045, Pessac, France.
authors.forename: Hubert
authors.initials: H
authors.lastname: Cochet
authors.forename: Daniel
authors.initials: D
authors.lastname: Scherr
authors.forename: Stephan
authors.initials: S
authors.lastname: Zellerhoff
authors.forename: Frederic
authors.initials: F
authors.lastname: Sacher
authors.forename: Nicolas
authors.initials: N
authors.lastname: Derval
authors.forename: Arnaud
authors.initials: A
authors.lastname: Denis
authors.forename: Sebastien
authors.initials: S
authors.lastname: Knecht
authors.forename: Yuki
authors.initials: Y
authors.lastname: Komatsu
authors.forename: Michel
authors.initials: M
authors.lastname: Montaudon
authors.forename: François
authors.initials: F
authors.lastname: Laurent
authors.forename: Burkert M
authors.initials: BM
authors.lastname: Pieske
authors.forename: Mélèze
authors.initials: M
authors.lastname: Hocini
authors.forename: Michel
authors.initials: M
authors.lastname: Haïssaguerre
authors.forename: Pierre
authors.initials: P
authors.lastname: Jaïs
mesh_terms: D000200:Action Potentials; D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D016279:Atrial Function, Left; D064752:Atrial Remodeling; D017115:Catheter Ablation / Q000009:adverse effects*; D002921:Cicatrix / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology; D003187:Compliance; D005080:Exercise Test; D005260:Female; D006325:Heart Atria / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009200:Myocardial Contraction; D013997:Time Factors; D016896:Treatment Outcome
keywords: atrial fibrillation; atrial remodeling; catheter ablation; magnetic resonance imaging