Mitral annuloplasty for atrial functional mitral regurgitation in patients with chronic atrial fibrillation.

Background: Surgical ring annuloplasty is generally performed in patients with symptomatic atrial functional mitral regurgitation (MR) caused by long-standing atrial fibrillation (AF). However, its clinical results have not been well reported.

Methods: Twenty consecutive patients with atrial functional MR (mean age of 68 ± 9 years) and a left ventricular (LV) ejection fraction (EF) greater than 50% underwent mitral annuloplasty. Concomitant procedures included tricuspid valve surgery in 16 patients, AF ablation in 13 patients, and coronary artery bypass grafting in 2 patients. We reviewed the clinical outcomes of those patients and investigated the specific preoperative echocardiographic findings related to MR recurrence.

Results: At discharge, the mean left atrial (LA) volume index and mean tricuspid regurgitation peak gradient had significantly decreased from 94 ± 59 mL/m to 58 ± 30 mL/m and from 34 ± 11mm Hg to 23 ± 5mm Hg, respectively. During the follow-up period of 28 ± 17 months, the New York Heart Association functional class significantly improved from 2.3 ± 0.6 to 1.3 ± 0.6. Four patients developed recurrent MR, and of those, two required reoperation. Those with recurrent MR had a significantly larger preoperative LV dimension than those without recurrent MR. Preoperative three-dimensional transesophageal echocardiography was performed in 12 patients, revealing a greater degree of leaflet tethering in patients with recurrent MR than that in patients without recurrent MR.

Conclusions: In patients with the combination of atrial functional MR, left ventricular dilatation and excessive leaflet tethering, mitral annuloplasty alone may not be sufficient to achieve long-term correction of MR.