Edge-to-edge mitral valve repair without ring annuloplasty for acute ischemic mitral regurgitation

Background - Alfieri edge-to-edge mitral repair has been used clinically with ring annuloplasty to correct ischemic mitral regurgitation (IMR), but its efficacy without concomitant ring annuloplasty has not been described in this setting. Methods - Seventeen sheep underwent implantation of 9 radiopaque markers on the left ventricle, 8 on the mitral annulus (MA), 1 on each papillary muscle (PM) tip, and 1 on the anterior and posterior leaflet edges near the anterior and posterior commissures. Alfieri repair was performed in 7 animals, and 10 were controls. Biplane videofluoroscopy and transesophageal echocardiography (TEE) were performed (open chest) before and continuously during left circumflex coronary artery occlusion to induce acute IMR. MA area (MAA), anterior (APM), and posterior (PPM) papillary muscle tip distances to midseptal MA ("saddle horn"), and distance of each leaflet marker to the mitral annular plane were calculated from 3-dimensional marker coordinates at end-systole (ES). Results - Severity of IMR was not different between groups (+1.9±0.7 versus +1.4±0.5 for Control and Alfieri, respectively; P=not significant [NS]). Mitral annular area (MAA; 21±15 versus 19±9%; P=NS) and septal-lateral (SL) annular diameter (12±6 versus 12±11%; P=NS) increased similarly during ischemia. While PPM-saddle horn distance increased in both groups (1.5±1.3 and 1.6±1.4 mm for Control and Alfieri, respectively; P<0.05 versus preischemia), APM-saddle horn distance increased in Control (1.0±1.2 mm; P=0.03) but not in the Alfieri animals (0.8±08 mm; P=0.07). Leaflet edge displacements from the annular plane during ischemia were similar in both groups. Conclusions - Alfieri repair did not prevent acute IMR nor alter ischemic valvular or subvalvular geometric perturbations. Adjunct surgical procedures, such as ring annuloplasty, are also necessary.