Left Atrium Volume Reduction Procedure Concomitant With Cox-Maze Ablation in Patients Undergoing Mitral Valve Surgery: A Meta-Analysis of Clinical and Rhythm Outcomes

Abstract

Background: The management of an enlarged left atrium (LA) in mitral valve (MV) disease with atrial fibrillation (AF) is still being debated. It has been postulated that a reduction in LA size may improve patient outcomes. This meta-analysis aimed to assess rhythm and clinical outcomes of combined surgical AF treatment with or without LA volume reduction (LAVR) in patients undergoing MV surgery.

Methods: A systematic review was performed and all available literature to May 2022 was included. The primary endpoint was analysis of early and late mortality and rhythm outcomes. Secondary outcomes included early and late cerebrovascular accident (CVA) and permanent pacemaker implantation.

Results: The search strategy yielded 2,808 potentially relevant articles, and 19 papers were eventually included. The pooled estimated rate of 30-day mortality was 3.76% (95% CI 2.52-5.56). The incidence rate of late mortality and late cardiac-related mortality was 1.75%/year (95% CI 0.63-4.84) and 1.04%/year (95% CI 0.31-3.53), respectively. At subgroup analysis when comparing the surgical procedure with and without AF ablation, the ablation subgroup showed a significantly lower rate of postoperative CVA (p<0.0001) and higher restoration to sinus rhythm at discharge (p=0.0124), with only a trend of lower AF recurrence at 1 year (p=0.0608). At univariable meta-regression, reintervention was significantly associated with higher late mortality (p=0.0033).

Conclusion: In enlarged LA undergoing MV surgery, LAVR combined with AF ablation showed a trend of improved rhythm outcomes when compared with AF ablation without LAVR. Each LAVR technique has its advantages and disadvantages, which must be managed accordingly.

Keywords: Atrial fibrillation ablation; Cardiac surgery; Left atrium volume reduction surgery; Meta-analysis; Mitral valve surgery.