title: Consequence of atrial fibrillation and the risk of embolism after percutaneous mitral commissurotomy: the necessity of the maze procedure.
abstract: BACKGROUND
  We sought to investigate the incidence and risk of embolism after percutaneous balloon mitral commissurotomy (PMC) and delineated the necessity of the maze procedure in patients with atrial fibrillation (AF).
  
  
  METHODS
  Clinical records of 326 patients, who underwent PMC between April 1988 and March 2003, and 162 patients, who underwent mitral valve surgery (MVS) combined with the maze procedure (MVS/maze) in the same period, were reviewed. We examined the consequence of cardiac rhythm and the incidence and risk of embolism after PMC. Next our current criteria for indication of the maze procedure, which included duration of AF less than 10 years, voltage of f wave on electrocardiography greater than 0.1 mV, cardiothoracic ratio less than 70%, and left atrial dimension less than 70 mm, were applied to all patients. These criteria were satisfied by 190 patients of PMC (PMC group) and 114 patients of MVS/maze (MVS/maze group) and the early and late results of the two groups were compared.
  
  
  RESULTS
  Thirty-eight patients suffered from embolic complications after PMC. Of these 33 patients experienced AF before intervention. The actuarial embolism-free rate at 10 years was 81.9% in patients with AF before PMC and 92.9% in patients with sinus rhythm before PMC (p = 0.01). Univariate predictors of embolism after PMC included previous embolic history (p = 0.01), AF (p = 0.01), pressure gradient (p = 0.01), age (p = 0.03), and mitral valve area (p = 0.04). Multivariate analysis identified AF as the independent predictor of embolism in the late follow-up period (p = 0.03). In a comparative study of the selected patients the actuarial AF-free rates after MVS/maze were 89.9% at 1 year and 85.7% at 5 years and were significantly higher than those of 17.3% at 1 year and 4.2% at 5 years after PMC (p < 0.0001). The actuarial embolism-free rate in the MVS/maze group was 98.0% at 5 years and was significantly higher than that of 84.8% at 5 years and 82.4% at 10 years in the PMC group (p = 0.01).
  
  
  CONCLUSIONS
  PMC alone is not sufficient with regard to sinus rhythm recovery and prevention of embolism. Surgical treatment concomitant with the maze procedure may be beneficial for patients with AF.
authors.affiliation: Department of Cardiovascular Surgery, National Cardiovascular Center, Osaka, Japan. hnakajim@hsp.ncvc.go.jp
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakajima
authors.forename: Junjiro
authors.initials: J
authors.lastname: Kobayashi
authors.forename: Ko
authors.initials: K
authors.lastname: Bando
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Yasumura
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nakatani
authors.forename: Kohji
authors.initials: K
authors.lastname: Kimura
authors.forename: Kazuo
authors.initials: K
authors.lastname: Niwaya
authors.forename: Osamu
authors.initials: O
authors.lastname: Tagusari
authors.forename: Soichiro
authors.initials: S
authors.lastname: Kitamura
mesh_terms: D001281:Atrial Fibrillation / Q000453:epidemiology* / Q000628:therapy; D002315:Cardiopulmonary Bypass; D017115:Catheter Ablation / Q000706:statistics & numerical data*; D015897:Comorbidity; D018572:Disease-Free Survival; D004617:Embolism / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D008946:Mitral Valve Stenosis / Q000453:epidemiology* / Q000601:surgery*; D011237:Predictive Value of Tests; D012044:Regression Analysis; D012214:Rheumatic Heart Disease / Q000453:epidemiology* / Q000601:surgery*; D018570:Risk Assessment; D016019:Survival Analysis; D016896:Treatment Outcome