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 Masao Daimon, MD, A. Marc Gillinov, MD, John R. Liddicoat, MD, Giuseppe Saracino, MS, Shota Fukuda, MD, Yasushi Koyama, MD, Motoya Hayase, MD, William E. Cohn, MD, Stephen G. Ellis, MD, FACC, James D. Thomas, MD, FACC, and Takahiro Shiota, MD, FACC, Cleveland, Ohio; Boston, Massachusetts; and Houston, Texas We used a novel 3-dimensional (3D) echocardio- graphic technique to evaluate the impact of a coro- nary 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 cm 2 , P < .001 for both, respectively) with reduction of mitral regurgitation jet area (5.1  2.3-1.2  0.8 cm 2 , 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 quantita- tive analysis of the impact of PTMA. (J Am Soc Echocardiogr 2007;20:381-388.) Functional mitral regurgitation (MR), which occurs as a consequence of altered left ventricular (LV) function and geometry despite a structurally normal mitral valve, is common in patients with ischemic or primary myocardial disease. Functional MR plays a pivotal role in the pathophysiology of congestive heart failure, and the greater the degree of MR, the worse the prognosis. 1,2 Surgical annuloplasty is the only available direct treatment for functional MR and may improve symptoms and prognosis in patients with congestive heart failure. 3-5 However, high mor- bidity and mortality associated with the surgical procedure limit its application. These findings point to the need for the development of alternate ap- proaches for treatment of functional MR. As new treatments for functional MR are developed, investi- gators must study both their impact on mitral func- tion and their impact on clinical outcomes. Ischemic MR (IMR) is the type of functional MR encountered most often, and its complex patho- physiology is related to asymmetric alterations in annular and ventricular geometry and function. 6-12 Recently, we reported that percutaneous trans- venous mitral annuloplasty (PTMA) using a novel device that exploits the anatomic proximity of the coronary sinus to the mitral apparatus effectively reduced chronic IMR in an ovine model. 13 Likewise, several investigators have reported percutaneous catheter-based approaches to mitral annuloplasty by the coronary sinus in animal models of acute IMR 14 or MR caused by dilated cardiomyopathy. 15-17 How- ever, there is a paucity of data describing the impacts of these approaches on mitral annular ge- ometry and function. The mitral annulus has complex geometry, includ- ing an asymmetric elliptic shape with a saddle- shaped 3-dimensional (3D) structure, and there are dynamic changes in its shape and position during the cardiac cycle. 18-20 Changes in mitral annular geometry and motion play important roles in the generation of functional MR. 6-8 In addition, mitral annular function also contributes to both systolic From the Cleveland Clinic Foundation; Beth Israel Deaconess Medical Center, Boston (J.R.L.); Massachusetts General Hospital (M.H.); and Texas Heart Institute (W.E.C.). Supported by a research grant from Viacor Inc (Dr Daimon). Disclosure: Drs Liddicoat, Cohn, and Gillinov have equity inter- ests in Viacor Inc. Drs Shiota and Hayase have served as consult- ants to Viacor Inc. Reprint requests: Takahiro Shiota, MD, FACC, Department of Cardiovascular Medicine, Desk F15, Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44195 (E-mail: shiotat@ccf.org). 0894-7317/$32.00 Copyright 2007 by the American Society of Echocardiography. doi:10.1016/j.echo.2006.08.029 381