Abstract 14570: Aortic-Mitral Coupling in Transcatheter Aortic Valve Implantation: A 3D Echocardiographic Study

Abstract

Background: Normal aortic and mitral valves function in a reciprocal interdependent fashion. We hypothesized that the mitral valve function would be affected by severe aortic stenosis (AS) and that its function would remain altered after transcatheter aortic valve implantation (TAVI). Using three-dimensional (3D) echocardiography, we studied aortic-mitral coupling in AS patients undergoing TAVI and compared them to patients without AS.

Methods: 3D transesophageal echocardiography (Philips) was performed on 38 patients: 16 controls and 22 with severe AS, studied pre- and post-TAVI. Custom software tracked the aortic and mitral annuli (AA, MA), allowing automated measurements of AA and MA morphology, angle and motion throughout the cardiac cycle.

Results: Compared to controls, pre-TAVI patients had significantly reduced MA displacement, MA and AA areas (Table). Post-TAVI, MA displacement, MA and AA areas remained reduced. AA-MA angle was significantly wider at end-systole in pre-TAVI patients and became wider throughout the cardiac cycle post-TAVI. There was no difference in MA or AA dynamics between pre-TAVI patients with mild versus those with moderate-severe MA calcium, or between Edwards-Sapien and Medtronic CoreValve patients. A trend to reduced MA area was seen in those with moderate-severe MA calcium post-TAVI.

Conclusions: This study is the first to demonstrate that the effect of severe degenerative AS extends to a secondary, ‘unaffected’ valve, the mitral valve, due to calcification in the aortic-mitral fibrous continuity. TAVI does not result in recovery of mitral valve function as the prosthetic ring compresses the calcified aortic valve into the aortic-mitral fibrous continuity. These changes not only provide insight into a possible mechanism for prosthetic aortic valve failure, but also have implications in the future development of TAVI valves and possible need for mitral valve assessment before and after the procedure.