Mitral valve hemodynamic effects of percutaneous edge-to-edge repair with the MitraClip device for mitral regurgitation.

Introduction: The Endovascular Valve Edge-to-Edge REpair STudies (EVEREST) are investigating a percutaneous technique for edge-to-edge mitral valve repair with a repositionable clip. The effects on the mitral valve gradient (MVG) and mitral valve area (MVA) are not known.

Methods: Twenty seven patients with moderate to severe or severe mitral regurgitation (MR) were enrolled. Echocardiography was performed preprocedure, at discharge, and at 1, 6, and 12 months. Mean MVG was measured by Doppler and MVA by planimetry and pressure half-time, and evaluated in a central core laboratory. Pre- and postclip deployment, simultaneous left atrial/pulmonary capillary wedge and left ventricular pressures were obtained in eight patients.

Results: Three patients did not receive a clip, six patients had their clip(s) explanted by 6 months (none for mitral stenosis), and four were repaired with two clips. Results are notable for a slight increase in mean MVG by Doppler postclip deployment (1.79 +/- 0.89 to 3.31 +/- 2.09 mm Hg, P < 0.01) and an expected decrease in MVA by planimetry (6.49 +/- 1.61 to 4.46 +/- 2.14 cm(2), P < 0.001) and by pressure half time (4.35 +/- 0.98 to 3.01 +/- 1.42 cm(2), P < 0.05). There were no significant changes in hemodynamic parameters postclip deployment by direct pressure measurements. There was no change in MVA by planimetry from discharge to 12 months (3.90 +/- 1.90 to 3.79 +/- 1.54 cm(2), P = 0.78).

Conclusions: Echocardiographic and hemodynamic measurements after percutaneous mitral valve repair with the MitraClip show an expected decrease in mitral valve area with no evidence of clinically significant mitral stenosis either immediately after clip deployment or after 12 months of follow-up.