AIMS: The aim of this study was to evaluate the impact of two different transcatheter mitral valve replacement (TMVR) fixation strategies on the neo left ventricular outflow tract (neo-LVOT) and aorto-mitral angulation (AMA) after TMVR. METHODS AND RESULTS: Two different self-expandable nitinol valved stents were developed for transapical TMVR. In one group, the stents were fixed with an annular fixation system (ANN group, n=6). These prototypes were compared with an apical tether fixation TMVR system (AP group, n=11) in another group. Echocardiographic evaluation of the AMA and the neo-LVOT was conducted before and one hour after implantation. Maximal and minimal AMA (AMAmax and AMAmin) during the cardiac cycle of the AP group were significantly narrower than those of the ANN group (AMAmax: 39 ±8° vs. 67 ±15°, p<0.001, AMAmin: 33 ±10° vs. 56 ±22°, p=0.009). More severe reduction of the neo-LVOT diameter was observed in the ANN group (60 ±11% vs. 26 ±14%, p<0.001). The ANN group had a higher peak velocity through the neo-LVOT post-implantation (200 ±52cm/s vs. 108 ±15cm/s, p<0.001). CONCLUSIONS: The apical fixation system maintains a smaller and more stable aorto-mitral angulation and a larger neo-LVOT, thereby reducing the risk of postoperative neo-LVOT obstruction in this experimental setting.
AIMS: The aim of this study was to evaluate the impact of two different transcatheter mitral valve replacement (TMVR) fixation strategies on the neo left ventricular outflow tract (neo-LVOT) and aorto-mitral angulation (AMA) after TMVR. METHODS AND RESULTS: Two different self-expandable nitinol valved stents were developed for transapical TMVR. In one group, the stents were fixed with an annular fixation system (ANN group, n=6). These prototypes were compared with an apical tether fixation TMVR system (AP group, n=11) in another group. Echocardiographic evaluation of the AMA and the neo-LVOT was conducted before and one hour after implantation. Maximal and minimal AMA (AMAmax and AMAmin) during the cardiac cycle of the AP group were significantly narrower than those of the ANN group (AMAmax: 39 ±8° vs. 67 ±15°, p<0.001, AMAmin: 33 ±10° vs. 56 ±22°, p=0.009). More severe reduction of the neo-LVOT diameter was observed in the ANN group (60 ±11% vs. 26 ±14%, p<0.001). The ANN group had a higher peak velocity through the neo-LVOT post-implantation (200 ±52cm/s vs. 108 ±15cm/s, p<0.001). CONCLUSIONS: The apical fixation system maintains a smaller and more stable aorto-mitral angulation and a larger neo-LVOT, thereby reducing the risk of postoperative neo-LVOT obstruction in this experimental setting.
Authors: Faizus Sazzad; Jimmy Kim Fatt Hon; Kollengode Ramanathan; Jie Hui Nah; Zhi Xian Ong; Lian Kah Ti; Roger Foo; Edgar Tay; Theo Kofidis Journal: Front Cardiovasc Med Date: 2022-02-24