Surgical outcome of mitral valve surgery in atrial functional mitral regurgitation compared with degenerative etiology.

Objective: To analyze and compare the outcomes of mitral valve surgery for atrial functional mitral regurgitation (AFMR) and for degenerative mitral regurgitation (DMR).

Methods: Patients with AFMR or DMR who underwent mitral valve repair/replacement at 2 institutions between January 2012 and December 2022 were included. Patients <18 years of age and patients undergoing concomitant cardiac surgery (except for the maze procedure or tricuspid annuloplasty) were excluded. Propensity score analysis was used to adjust for baseline differences.

Results: A total of 642 patients were enrolled. After propensity score analysis, 164 patients were classified into the DMR group, and 82 patients were classified into the AFMR group. All matched patients in both groups had atrial fibrillation. In DMR and AFMR, the 5-year freedom from readmission for heart failure and cardiac death was 96.3% in the DMR group versus 88.6% in the AFMR group (P = .045) and freedom from readmission for cardiac death in the 2 groups was 100% and 90.0%, respectively (P = .002). The recurrence rate of significant mitral regurgitation (MR) after mitral valve repair was not significantly different between the 2 groups (P = .699, log-rank test), and the 5-year freedom from MR recurrence (moderate or greater) was 89.8% and 93.0%, respectively. After the maze procedure, significantly more patients in the AFMR group than the DMR group were in junctional rhythm (49.1% vs 3.3%; P < .001) and required permanent pacemaker insertion during the follow-up period (11.4% vs 1.5% after 5 years; P = .041, log-rank test).

Conclusions: AFMR was associated with acceptable outcomes of mitral valve surgery, and mitral valve repair is a good treatment option. However, significantly more patients were in junctional rhythm after the maze procedure, needing more permanent pacemaker insertion.