Mitral valve surgery plus concomitant atrial fibrillation ablation is superior to mitral valve surgery alone with an intensive rhythm control strategy.
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.
von Oppell
Ulrich O
UO
University Hospital Wales, Cardiff, United Kingdom.
Masani
Navroz
N
O'Callaghan
Peter
P
Wheeler
Richard
R
Dimitrakakis
Georgios
G
Schiffelers
Sandra
S
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