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.