title: Mitral valve replacement with or without a concomitant Maze procedure in patients with atrial fibrillation.
abstract: BACKGROUND
  Although the Maze procedure is regarded as the most effective way to restore sinus rhythm in patients with chronic atrial fibrillation (AF), it remains unclear whether this procedure offers long-term clinical benefits in patients undergoing mechanical valve replacement.
  
  
  RESULTS
  Between 1999 and 2007, 402 patients with AF-associated mitral valve (MV) disease underwent MV replacement with a mechanical prosthesis. Of these patients, 159 underwent valve replacement plus the Maze procedure, whereas 243 received valve replacement alone. The composite end points of cardiac death and cardiac-related morbidities were compared in these two groups using the inverse-probability-of-treatment-weighted method. At a median follow-up time of 63.1 months (range 0.2-123.9 months), patients who had undergone the Maze procedure were at significantly lower risk of thromboembolic events (hazard ratio (HR)=0.26, 95% confidence interval (CI) 0.07 to 0.95; p=0.041) and were at comparable risk of death (HR=0.96, 95% CI 0.44 to 2.07; p=0.907) and cardiac death (HR=1.26, 95% CI 0.53 to 3.01; p=0.598) compared with patients who underwent MV replacement alone. The composite risk of death or major events was lower in the Maze procedure group (HR=0.64, 95% CI 0.38 to 1.08; p=0.093).
  
  
  CONCLUSIONS
  Compared with MV replacement alone, the addition of the Maze procedure was associated with a reduction in thromboembolic complications and better long-term event-free survival in patients with AF undergoing mechanical MV replacement. Prospective randomised data are necessary to confirm the findings of this study.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Pungnap-dong Songpa-gu, Seoul 138-736, South Korea.
authors.forename: Joon Bum
authors.initials: JB
authors.lastname: Kim
authors.forename: Min Ho
authors.initials: MH
authors.lastname: Ju
authors.forename: Sung Cheol
authors.initials: SC
authors.lastname: Yun
authors.forename: Sung Ho
authors.initials: SH
authors.lastname: Jung
authors.forename: Cheol Hyun
authors.initials: CH
authors.lastname: Chung
authors.forename: Suk Jung
authors.initials: SJ
authors.lastname: Choo
authors.forename: Taek Yeon
authors.initials: TY
authors.lastname: Lee
authors.forename: Hyun
authors.initials: H
authors.lastname: Song
authors.forename: Jae Won
authors.initials: JW
authors.lastname: Lee
mesh_terms: D000328:Adult; D001281:Atrial Fibrillation / Q000150:complications / Q000601:surgery*; D004812:Epidemiologic Methods; D005260:Female; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery*; D008944:Mitral Valve Insufficiency / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D012214:Rheumatic Heart Disease / Q000150:complications / Q000601:surgery; D013923:Thromboembolism / Q000209:etiology / Q000517:prevention & control; D016896:Treatment Outcome; D014463:Ultrasonography