Dynamic Change in Mitral Annular Area and Motion During Percutaneous Mitral Annuloplasty for Ischemic Mitral Regurgitation: Preliminary Animal Study With Real-time 3-Dimensional Echocardiography

We used a novel 3-dimensional (3D) echocardiographic technique to evaluate the impact of a coronary sinus-based percutaneous transvenous mitral annuloplasty (PTMA) on dynamic changes in mitral annular geometry and motion during the cardiac cycle in 8 sheep with ischemic mitral regurgitation. Using real-time 3D echocardiographic data before and after PTMA, 10 points along the saddle-shaped annulus were identified. For every 3D volume/frame during a cardiac cycle, we assessed mitral annular area and excursion defined as the traveling distance of the annular center. The PTMA device reduced both minimum and maximal mitral annular area (9.5 ± 0.9-7.0 ± 0.6 and 12.8 ± 1.3-9.8 ± 1.5 cm², P < .001 for both, respectively) with reduction of mitral regurgitation jet area (5.1 ± 2.3-1.2 ± 0.8 cm², P < .001), whereas it did not significantly impair mitral annular excursion amplitude (8.3 ± 1.1-7.0 ± 1.9 mm, P = .13). This 3D echocardiographic method noninvasively enabled dynamic study of mitral annular geometry and motion with quantitative analysis of the impact of PTMA.