Abstract 11124: Mitral Annular Calcification Mitral Stenosis: Obstruction is in the Tunnel

• Published in: Circulation (New York, N.Y.) N.Y.), 2021-11, Vol.144 (Suppl_1), p.A11124-A11124
• Main Authors: Friend, Evan, Murthy, Kinnari, Qamruddin, Salima, Pressman, Gregg S
• Format: Article
• Language: English
• ISSN: 0009-7322; 1524-4539
• DOI: 10.1161/circ.144.suppl_1.11124

BackgroundMitral annular calcification (MAC) is an increasingly encountered cause of mitral stenosis. As opposed to rheumatic disease, in MAC the commissures are typically open. In some cases the leaflet tips remain freely mobile while in others they are restricted. We sought to determine if mean mitral valve gradient (MVG) is associated with the minimal area in the MAC tunnel or the area at the leaflet tips. MethodsHigh quality 3D TEE datasets were acquired in 10 subjects with severe bulky MAC. Custom 2D cut planes were created at the mitral valve inlet, the narrowest portion of the MAC tunnel, and at the leaflet tips (figure 1), and compared with MVG by continuous wave Doppler. ResultsArea at the annular inlet ranged from 5.4 - 11.0 cm2 (mean 8.2). The smallest area within the tunnel ranged from 1.3 - 4.0 cm2 (mean 2.4) while the smallest area at the leaflet tips ranged from 1.0 - 2.6 cm2 (mean 1.6). MVG ranged from 3 - 14 (mean 8) mm Hg. As annular inlet area decreased MVG increased (r2 = 0.49, p = 0.024). Similarly, as minimum tunnel area decreased MVG increased (r2 = 0.54, p = 0.015; figure 2). There was a no significant relation between MVG and smallest leaflet area (r2 = 0.17, p = 0.23). There was also no association between degree or distribution of MAC, and MVG or smallest tunnel area. ConclusionsIn subjects with severe MAC and a resting gradient across the valve, obstruction to flow occurs at the annular inlet and within the calcium tunnel. In contrast to rheumatic mitral stenosis, valve area at the leaflet tips does not appear to determine the MVG.