Left atrial reduction in modified maze procedure with concomitant mitral surgery.
BACKGROUND
An association between mitral valve disease and atrial fibrillation is common. Modifications of energy sources have simplified surgical ablation. Left atrial size reduction should improve outcomes of the maze operation.


METHODS
Between 2004 and 2011, 236 patients with permanent atrial fibrillation and mitral valve disease underwent mitral valve surgery and modified biatrial radiofrequency ablation. The study evaluated cardiac rhythm, atrial size, atrial contractility, and survival.


RESULTS
The mitral valve was repaired in 88 (37.3%) patients and replaced in 148 (62.7%). The left atrium was reduced in 192 (81.4%) patients: 31 (13.1%) had posterior wall reduction and 161 (68.2%) had right lateral and posterior wall resection. The 30-day mortality was 4.2% (10/236). The median follow-up was 41 months. Actuarial freedom from atrial fibrillation at 1 year and last follow-up was 87.7% and 84.9%, respectively. Predictors of recurrence were preoperative left atrial diameter >60 mm (p = 0.002), postoperative diameter >50 mm (p < 0.001), atrial fibrillation on day 7 (p < 0.001), and technique of reduction (posterolateral/posterior) in patients with atrial size >60 mm (p = 0.017). Atrial fibrillation during follow-up (p = 0.002) and age >60 years (p = 0.003) were significant predictors of poorer survival. During 5-year follow-up, non-atrial fibrillation patients survived significantly longer than atrial fibrillation patients (p = 0.002).


CONCLUSIONS
Radiofrequency ablation is an effective option for treatment of permanent atrial fibrillation concomitant with mitral valve surgery. Atrial reduction to <50 mm improves success. Elimination of atrial fibrillation significantly prolongs patient survival.
Department of Cardiothoracic Surgery, Central Chest Institute of Thailand, Nonthaburi, Thailand.
Choosak
C
Kasemsarn
Piyawat
P
Lerdsomboon
Vibhan
V
Sungkahaphong
Taweesak
T
Chotivatanapong
D000328:Adult; D001281:Atrial Fibrillation / Q000150:complications / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D006332:Cardiomegaly / Q000175:diagnosis / Q000209:etiology*; D017115:Catheter Ablation / Q000009:adverse effects / Q000401:mortality; D018572:Disease-Free Survival; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging / Q000601:surgery; D006349:Heart Valve Diseases / Q000150:complications / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects / Q000401:mortality; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000503:physiopathology / Q000601:surgery*; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014463:Ultrasonography
Atrial fibrillation; Catheter ablation; Heart atria; Mitral valve; Survival rate; Treatment outcome