Early and mid-term results of surgical treatment for atrial functional mitral regurgitation: Impact of extended posterior leaflet augmentation

Atrial functional mitral regurgitation (AFMR) is caused by mitral annular dilatation and "hamstringing" of the posterior leaflet associated with permanent atrial fibrillation (AF) -induced severe left atrial dilation.Isolated mitral annuloplasty (MAP) may be inadequate to prevent mitral regurgitation (MR) recurrence, especially in advanced stages.To manage AFMR, we combined extended posterior leaflet augmentation with MAP to obtain an effective coaptation length.We investigated 45 patients with permanent AF and AFMR, 20 (44.4％) of whom were New York Heart Association class III or IV.Of the 45 patients, 26 (57.8％) were in advanced stage (complex of severe left atrial and left ventricular enlargement, left ventricular dysfunction, and severe MR grade) and underwent MAP with extended posterior leaflet augmentation ; 19 (42.2％) were in early stage and underwent MAP without leaflet augmentation.The coaptation length in the midsystolic parasternal long-axis view was calculated using echocardiography and compared in both groups.Patients with advanced stage demonstrated a larger mitral annular diameter.Except for two patients, MR was rated mild or lower up to 4 years postoperatively.Follow-up echocardiography revealed sufficient coaptation length in both groups (9.0 and 7.0 mm in the advanced-stage and early stage groups, respectively, throughout the 3-year follow-up period) .The overall 4-year freedom from cardiacrelated mortality was 90.4％.Recurrence of MR ≥ mild was 5.0％, and the 4-year reoperation rate was 2.6％ (advanced stage, 4.2％ ; early stage, 0％ ; p ＝0.323) .Extended posterior leaflet augmentation was effective for patients with advanced-stage AFMR, yielding sufficient coaptation length, excellent freedom from recurrent MR, and survival comparable to patients with early stage AFMR.