Long-term functional improvement following left atrial reduction plasty for giant left atrium

Objective: Several techniques for left atrial (LA) reduction plasty have been proposed mainly in the context of surgery for atrial fibrillation. We developed a modification of the traditional plication technique and evaluated its impact on long-term cardiorespiratory function

Methods: Between 1995 and 2003, forty-three patients (age: 32–80yrs, 67% females) with giant left atrium (LA volume >250ml) underwent LA reduction plasty at the time of mitral valve surgery. Following mitral valve repair, closure of the atrial appendage and high frequency ablation (Maze), parallel buttressed plication sutures are placed in the posterior LA wall, tightened, and oversewn with a longitudinal running suture. All patients were in atrial fibrillation, 41 (95%) also had tricuspid regurgitation, 16 were in NYHA class IV and 25 (58%) in class III. Patients were followed by chest X-ray, echocardiography, CT scan, Holter ECG and lung function tests. LA size was quantified in 3 defined planes (width: left and right pulmonary veins; length: mitral valve ring – LA roof; height: aorta – LA wall) and normalized for body surface area.

Results: Thirty-day mortality was 11% (n=5) and Kaplan-Meier estimated 10 year survival was 54%. At follow-up, only 5 patients (12%) were in normal sinus rhythm, 4 (9%) had permanent pacing, and 36 (84%) had residual or recurrent atrial fibrillation. Cardiothoracic ratio decreased from 0.66±0.09 to 0.55±0.09 (p=0.001) and carinal angle from 105±14° to 90±11°. LA width was reduced from 83±38 to 59±13mm (p<0.0001), and normalized LA size index decreased from 50±24 to 32±7mm/m². Inspiratory vital capacity increased from 2.11±0.8l to 2.6±0.8l (p=0.012), and forced expiratory volume from 1.47±0.6l to 1.71±0.7l (p=0.01). At follow-up, all surviving patients were either were either in NYHA class I or II (p<0.0001 compared to preoperative).

Conclusion: Patients with advanced mitral valve disease and giant right atrium have limited long-term survival. LA reduction plasty plus Maze eliminate atrial fibrillation only in a small fraction of patients, but the reduced LA dimension leads to measurably improved lung function.