Percutaneous mitral valve repair for chronic ischemic mitral regurgitation - A real-time three-dimensional echocardiographic study in an ovine model

Background-Although surgical annuloplasty is the standard repair for ischemic mitral regurgitation (IMR), its application is limited by high morbidity and mortality. Using 2D and real-time 3D echocardiography in an ovine model of chronic IMR, we evaluated the geometric impact and short-term efficacy of a percutaneous transvenous catheter-based approach for mitral valve (MV) repair using a novel annuloplasty device placed in the coronary sinus. Methods and Results-Six sheep developed IMR 8 weeks after induced posterior myocardial infarction. An annuloplasty device optimized to reduce anterior-posterior (A-P) mitral annular dimension and MR was placed percutaneously in the coronary sinus. Mitral annular A-P and commissure-commissure dimensions and MV tenting area (MVTa) in 3 parallel A-P planes (medial, central, and lateral) were assessed by real-time 3D echocardiography with 3D software. The annuloplasty device reduced MR jet area from 5.4 +/- 2.6 to 1.3 +/- 0.9 cm(2) (P < 0.01), mitral annular A-P dimension in both systole and diastole (24.3 +/- 2.5 to 19.7 +/- 2.4 mm; P < 0.03; 31.0 +/- 3.9 to 24.7 +/- 2.1 mm; P < 0.001), and MVTa at mid systole in all 3 planes (153 +/- 46 to 93 +/- 24 mm(2), P < 0.01; 140 +/- 47 to 88 +/- 23 mm(2), P < 0.03; and 103 +/- 23 to 87 +/- 26 mm(2), P < 0.03). Conclusions-Percutaneous coronary sinus-based mitral annuloplasty reduces chronic IMR by reducing mitral annular A-P diameter and MVTa. This suggests the potential clinical application of a new nonsurgical therapeutic approach in patients with IMR.