Percutaneous Mitral Valve Repair Preserves Right Ventricular Function

Background: Chronic mitral regurgitation (MR) often leads to diminished right ventricular (RV) function due to long-standing pressure and volume overload. Surgical intervention often adds to the preexisting RV dysfunction. Percutaneous mitral valve (MV) repair can reduce MR, but to what extent this affects the right ventricle is unknown. Methods: Consecutive patients scheduled for percutaneous MV repair using the MitraClip system underwent transthoracic echocardiography at baseline and at 1- and 6-month follow-up. RV systolic function was evaluated using five echocardiographic parameters. RV afterload was evaluated using systolic pulmonary arterial pressure and the mean MV pressure gradient. Residual MR was defined as grade >= 3 and mitral stenosis (MS) as a mean MV pressure gradient >= 5 mm Hg. Results: Sixty-eight patients (52% men; mean age, 75 +/- 10 years) were included. Six months after MitraClip implantation, there were no significant changes in any of the RV parameters. MR decreased (P < .01) and the mean MV pressure gradient increased during follow-up (2.3 +/- 1.4 mm Hg at baseline vs 4.5 +/- 2.7 mm Hg at 6 months, P < .01). Patients with both residual MR and MS 6 months after MitraClip implantation showed significantly higher systolic pulmonary arterial pressure values (P < .01) and lower New York Heart Association functional classes (P < .01) compared with patients without residual MR or MS. Conclusions: Percutaneous MV repair, in contrast to surgical repair or replacement, does not negatively affect RV function. After repair, RV afterload and New York Heart Association functional class are improved in the case of successful repair but adversely affected in the presence of both residual MR and MS.