title: Surgical ablation of atrial fibrillation in patients with a giant left atrium undergoing mitral valve surgery.
abstract: As the efficacy of surgical ablation for atrial fibrillation (AF) is reported to be suboptimal for patients with a giant left atrium (LA), its routine use on this population has remained controversial. We sought to evaluate the clinical outcomes of patients with a giant LA undergoing mitral valve (MV) surgery with/without the maze procedure.
  
  
  
  We identified 759 patients with a giant LA (>60 mm) and AF undergoing MV surgery from 1999 through 2012. Of these, 400 underwent MV surgery with the maze procedure (maze group), and the remainder (n=359) underwent MV surgery only (no-maze group). To reduce the impact of selection bias, propensity score analyses were performed based on 25 baseline covariates.
  
  
  
  Early death occurred in five (1.3%) and nine (2.5%) patients in the maze and the no-maze group, respectively (p=0.28). Freedom from AF at 5 years was 68.9% in the maze group and 9.6% in the no-maze group (p<0.001). After adjustment, the maze group showed a significantly lower risk of death (HR, 0.65; 95% CI 0.44 to 0.98; p=0.038), thromboembolic events (HR, 0.23; 95% CI 0.09 to 0.58; p=0.002) and composite adverse outcomes (death, congestive heart failure and valve-related complications; HR, 0.55; 95% CI 0.42 to 0.71; p<0.001) than the no-maze group. In subgroup analyses, MV surgery with the maze procedure resulted in higher survival and event-free survival in most risk subgroups than without the maze procedure.
  
  
  
  The concomitant maze procedure improved postoperative rhythm status, clinical outcomes and cardiac functions in patients with a giant LA undergoing MV surgery. This study indicates that the patients with a giant LA undergoing MV surgery may benefit from an addition of the maze procedure.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Ho Jin
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Joon Bum
authors.initials: JB
authors.lastname: Kim
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Sung-Ho
authors.initials: SH
authors.lastname: Jung
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Suk Jung
authors.initials: SJ
authors.lastname: Choo
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Cheol Hyun
authors.initials: CH
authors.lastname: Chung
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Jae Won
authors.initials: JW
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D006348:Cardiac Surgical Procedures / Q000009:adverse effects / Q000401:mortality; D017115:Catheter Ablation / Q000009:adverse effects / Q000401:mortality; D016009:Chi-Square Distribution; D003452:Cryosurgery / Q000009:adverse effects / Q000401:mortality; D016208:Databases, Factual; D018572:Disease-Free Survival; D004452:Echocardiography; D015716:Electrocardiography, Ambulatory; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D006349:Heart Valve Diseases / Q000000981:diagnostic imaging / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D016017:Odds Ratio; D057216:Propensity Score; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome