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 cm2 (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 mm2, P<0.01; 140±47 to 88±23 mm2, P<0.03; and 103±23 to 87±26 mm2, 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.