Surgical Atrial Fibrillation Ablation With and Without Left Atrium Reduction for Patients Scheduled for Mitral Valve Surgery: A Prospective Randomised Study

Abstract

The influence of left atrium (LA) enlargement on atrial arrhythmia recurrence (AAR) after surgical ablation in patients with mitral valve (MV) disease remains unresolved. Left atrial size is critical to the success of concomitant atrial fibrillation (AF) ablation in patients scheduled for MV surgery. However, a large LA should not be a limiting factor when evaluating surgical candidates with AF if they receive appropriate treatment during concomitant ablation. This randomised study assessed whether adding LA reduction (LAR) to the maze procedure for MV surgery patients can improve freedom from AAR. From September 2014 to September 2017, 140 patients were randomly assigned into two groups. The maze group underwent MV surgery with concomitant surgical AF ablation (n=70). The maze+ LA reduction group underwent MV surgery with concomitant AF ablation and LA reduction procedure (n=70). Rhythm outcomes were estimated by Holter monitoring, according to Heart Rhythm Society guidelines. The concomitant LA reduction procedure did not increase early mortality and complications rates. Significant differences in freedom from AAR were observed at 24 months (maze, 78.4%; maze+ LAR group, 92.3%; p=0.025). A significant difference in LA volume was detected at discharge (p<0.0001); however, it was not significantly different at 24 months (p=0.182). Adding LA reduction to the maze procedure led to improvements in freedom from AAR for patients with AF and LA enlargement scheduled for MV surgery. A concomitant LA reduction procedure did not increase mortality and perioperative risk.