Isolated undersized mitral annuloplasty for functional mitral regurgitation in non-ischemic dilated cardiomyopathy: reconsideration of the relationship between preoperative coaptation depth and persistent mitral regurgitation.

Background: A preoperative coaptation depth (CD) >or=11 mm is apparently a predictive factor for persistent mitral regurgitation (MR) after undersized mitral annuloplasty for functional MR. The results of studies of isolated undersized mitral annuloplasty in non-ischemic dilated cardiomyopathy (DCM) are reported, including the relationship between the preoperative CD and recurrent MR.

Methods And Results: Six patients (mean age, 61 years) with severe functional MR in non-ischemic DCM underwent isolated undersized mitral annuloplasty. There were no hospital deaths. At intermediate follow-up of 2.2+/-1.9 years, New York Heart Association functional class improved significantly from 3.3+/-0.5 before surgery to 2.2+/-0.4 after surgery (p=0.0016). At a mean echocardiographic follow-up of 1.9+/-1.7 years, MR grade improved significantly from 4.0+/-0.0 before surgery to 1.0+/-0.6 after surgery (p<0.001). In 4 of 5 patients with a preoperative CD >or=11 mm, functional MR improved to mild or less than mild after surgery.

Conclusions: Isolated undersized mitral annuloplasty improved clinical symptoms and functional MR in non-ischemic DCM. These results suggest that preoperative CD >or=11 mm does not always predict recurrent MR after isolated undersized mitral annuloplasty for functional MR in cases of non-ischemic DCM.