TRANSCATHETER AORTIC VALVE IMPLANTATION PRESERVES MITRAL VALVE 3D GEOMETRY BETTER THAN STANDARD AVR

Abstract

Abstract Category: PCI - Valvular; Atrial Fibrillation TherapiesPresentation Number: 2901-08Authors: mathieu vergnat, Joseph Bavaria, Benjamin M. Jackson, Albert T. Cheung, Stuart J. Weiss, Joseph H. Gorman III, Robert C. Gorman, University of Pennsylvania, Philadelphia, PA Background: Moderate to severe mitral regurgitation (MR) is observed in 40% of patients undergoing transcatheter aortic valve implantation (TAVI). After open surgical aortic valve replacement (AVR), MR frequently improves. In TAVI, implantation is intra-annular, without leaflet resection and imposes radial anchoring forces on adjacent structures. Given the inherent differences in the technique, we hypothesized that TAVI could alter mitral annular geometry and exacerbate MR. Using three dimensional echocardiography, we investigated the impact TAVI and AVR on mitral annular geometry.Methods: Real-time three-dimensional echocardiography was performed in 20 patients undergoing TAVI (Sapien, Edwards Lifesciences, Irvine, CA) (n=10; 23mm in 7 patients) or AVR (n=10; 23±2mm) for severe stenosis. Comprehensive delineation of mitral annulus was performed using Tomtec EchoView. Multiple mitral annular geometric indexes were measured to assess regional and global annular geometry.All results are expressed as mean ± SEM.Results: After AVR, annular height decreased from 7.6±0.5 to 5.3±0.4mm (p=0.001), while no significant difference was found after TAVI (7.1±0.4 to 6.9±0.4mm, p=0.33). No significant modification of the commissural width occurred in either groups. Septo-lateral diameter decreased (32.3±1.6 to 29±1.5mm, p= 0.008) after AVR but was maintained after TAVI (31±1.3 to 30.5±1.4mm, p=0.12). Significant reduction of mitral annular area occurred after AVR (962±81 to 820±84mm2, p=0.001) while area was preserved after TAVI (892±64 to 869±69mm2, p=0.27). MR before implantation was respectively mild, moderate, or severe in 50% (40%), 42% (40%), and 9% (0%) of the patients, in the TAVI group (compared to AVR group). The degree of MR remained unchanged in 50 % (60%) and improved in 50% (40%) after TAVI (compared to AVR). No increase in MR occurred in either group.Conclusion: This study demonstrates the effect of aortic valve implantation on mitral annular geometry. Although leaflets are not resected in TAVI, this procedure preserves mitral annular geometry better than AVR. TAVI is thus not only less invasive, but may also be a more physiological approach to aortic replacement.