Yutaka Tanaka1, Shigeru Saito2, Saeko Sasuga3, Azuma Takahashi3, Yusuke Aoyama3, Kazuto Obama3, Mitsuo Umezu4, Kiyotaka Iwasaki5. 1. Cooperative Major in Advanced Biomedical Sciences, Joint Graduate School of Tokyo Women's Medical University and Waseda University, Waseda University, Tokyo, Japan; Department of Cardiology and Catheterization Laboratory, Shonan Kamakura General Hospital, Kamakura, Japan. 2. Department of Cardiology and Catheterization Laboratory, Shonan Kamakura General Hospital, Kamakura, Japan. 3. Center for Advanced Biomedical Sciences, Waseda University, Tokyo, Japan. 4. Cooperative Major in Advanced Biomedical Sciences, Joint Graduate School of Tokyo Women's Medical University and Waseda University, Waseda University, Tokyo, Japan; Center for Advanced Biomedical Sciences, Waseda University, Tokyo, Japan. 5. Cooperative Major in Advanced Biomedical Sciences, Joint Graduate School of Tokyo Women's Medical University and Waseda University, Waseda University, Tokyo, Japan; Center for Advanced Biomedical Sciences, Waseda University, Tokyo, Japan. Electronic address: iwasaki@waseda.jp.
Abstract
BACKGROUND: Quantitative assessment of post-transcatheter aortic valve replacement (TAVR) aortic regurgitation (AR) remains challenging. We developed patient-specific anatomical models with pulsatile flow circuit and investigated factors associated with AR after TAVR. METHODS: Based on pre-procedural computed tomography (CT) data of the six patients who underwent transfemoral TAVR using a 23-mm SAPIEN XT, anatomically and mechanically equivalent aortic valve models were developed. Forward flow and heart rate of each patient in two days after TAVR were duplicated under mean aortic pressure of 80mmHg. Paravalvular leakage (PVL) volume in basal and additional conditions was measured for each model using an electromagnetic flow sensor. Incompletely apposed tract between the transcatheter and aortic valves was examined using a micro-CT. RESULTS: PVL volume in each patient-specific model was consistent with each patient's PVL grade, and was affected by hemodynamic conditions. PVL and total regurgitation volume increased with the mean aortic pressure, whereas closing volume did not change. In contrast, closing volume increased proportionately with heart rate, but PVL did not change. The minimal cross-sectional gap had a positive correlation with the PVL volumes (r=0.89, P=0.02). The gap areas typically occurred in the vicinity of the bulky calcified nodules under the native commissure. CONCLUSIONS: PVL volume, which could be affected by hemodynamic conditions, was significantly associated with the minimal cross-sectional gap area between the aortic annulus and the stent frame. These data may improve our understanding of the mechanism of the occurrence of post-TAVR PVL.
BACKGROUND: Quantitative assessment of post-transcatheter aortic valve replacement (TAVR) aortic regurgitation (AR) remains challenging. We developed patient-specific anatomical models with pulsatile flow circuit and investigated factors associated with AR after TAVR. METHODS: Based on pre-procedural computed tomography (CT) data of the six patients who underwent transfemoral TAVR using a 23-mm SAPIEN XT, anatomically and mechanically equivalent aortic valve models were developed. Forward flow and heart rate of each patient in two days after TAVR were duplicated under mean aortic pressure of 80mmHg. Paravalvular leakage (PVL) volume in basal and additional conditions was measured for each model using an electromagnetic flow sensor. Incompletely apposed tract between the transcatheter and aortic valves was examined using a micro-CT. RESULTS: PVL volume in each patient-specific model was consistent with each patient's PVL grade, and was affected by hemodynamic conditions. PVL and total regurgitation volume increased with the mean aortic pressure, whereas closing volume did not change. In contrast, closing volume increased proportionately with heart rate, but PVL did not change. The minimal cross-sectional gap had a positive correlation with the PVL volumes (r=0.89, P=0.02). The gap areas typically occurred in the vicinity of the bulky calcified nodules under the native commissure. CONCLUSIONS: PVL volume, which could be affected by hemodynamic conditions, was significantly associated with the minimal cross-sectional gap area between the aortic annulus and the stent frame. These data may improve our understanding of the mechanism of the occurrence of post-TAVR PVL.
Authors: Dmitry Levin; G Burkhard Mackensen; Mark Reisman; James M McCabe; Danny Dvir; Beth Ripley Journal: Curr Cardiol Rep Date: 2020-02-17 Impact factor: 2.931
Authors: Anthony R Prisco; Jorge Zhingre-Sanchez; Lars Mattison; Demetris Yannopoulos; Ganesh Raveendran; Paul A Iaizzo; Sergey Gurevich Journal: Front Physiol Date: 2022-08-05 Impact factor: 4.755