title: Mitral valve surgery plus concomitant atrial fibrillation ablation is superior to mitral valve surgery alone with an intensive rhythm control strategy.
abstract: OBJECTIVE
  Prospective randomised study comparing patients with atrial fibrillation (AF) of more than 6 months duration after mitral valve surgery plus biatrial modified radiofrequency Maze procedure using Medtronic Cardioblate System (Cardioblate group, n=24) vs mitral valve surgery plus intensive rhythm control strategy (control group, n=25).
  
  
  METHODS
  Patients were blinded to randomisation. Preoperatively, at discharge, and at 3-month and 1-year follow-up, echocardiography, quality of life assessments and ECGs were done. In both groups, sinus rhythm (SR) restoration was attempted by intra- and postoperative DC cardioversion and class III antiarrhythmic medication. All patients received warfarin. Amiodarone and warfarin was considered for discontinuation after 3 months in SR, 24-h Holter or event monitor excluding AF.
  
  
  RESULTS
  Both groups underwent mitral valve replacement or repair (Cardioblate vs control: 16:8 vs 10:15), had similar gender (male: 33% vs 56%), age (66+/-8 years vs 68+/-9 years), additional aortic valve replacement (7 vs 6 patients), tricuspid annuloplasty (13 vs 13 patients), and CABG (10 vs 16 patients). There was 0% operative mortality, 0% postoperative cerebrovascular accidents, but 2 late deaths in the control group. At discharge, 3- and 12-month follow-up, more patients in the Cardioblate group returned to normal SR compared to control (29%, 57% and 75% vs 20%, 43% and 39%; p=0.030). Return of functional atrial contraction in patients in SR at 1 year was comparable between groups (63% vs 89%, NS), and more likely in non-rheumatic pathology and preoperative AF of shorter duration. The effectiveness of atrial contraction was 36+/-14% vs 43+/-18% of transmitral flow and there was no difference between groups. Amiodarone treatment decreased more in Cardioblate group over time (92%, 55% and 29% vs 52%, 52% and 21%; p=0.003), whereas warfarin decrease was comparable (100%, 100% and 71% vs 100%, 95% and 82%; NS).
  
  
  CONCLUSIONS
  Radiofrequency Maze ablation additional to mitral valve surgery resulted in a higher SR conversion rate (75%), despite control group treatment with intensive rhythm control strategy having a higher SR conversion rate (39%) compared to literature (approximately 25%). Maze ablation resulted in normalisation of atrial function in 63% of patients converted to SR.
authors.affiliation: University Hospital Wales, Cardiff, United Kingdom.
authors.forename: Ulrich O
authors.initials: UO
authors.lastname: von Oppell
authors.forename: Navroz
authors.initials: N
authors.lastname: Masani
authors.forename: Peter
authors.initials: P
authors.lastname: O'Callaghan
authors.forename: Richard
authors.initials: R
authors.lastname: Wheeler
authors.forename: Georgios
authors.initials: G
authors.lastname: Dimitrakakis
authors.forename: Sandra
authors.initials: S
authors.lastname: Schiffelers
mesh_terms: D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D004562:Electrocardiography; D004812:Epidemiologic Methods; D005260:Female; D006349:Heart Valve Diseases / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery*; D011788:Quality of Life; D016896:Treatment Outcome; D014463:Ultrasonography