Identifying risk factors for the post replacement-related complications following aortic valve replacement in patients with severe aortic valve stenosis with 4D-MRI blood flow dynamics imaging.

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K17510
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 53020:Cardiology-related
• Research Institution: Hokkaido University
• Principal Investigator: Kamiya Kiwamu 北海道大学, 大学病院, 助教 (60797108)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Keywords: 大動脈弁狭窄症 / 大動脈弁置換術 / 心不全

Outline of Final Research Achievements

Periprocedural hemodynamic changes, which could adversely affect outcomes after transcatheter aortic valve replacement (TAVR), have not been well investigated. Four-dimensional (4D) flow magnetic resonance imaging (MRI) enables accurate measurement of blood flow dynamics such as flow velocity, flow pattern, wall shear stress (WSS), and energy loss (EL). This study is an initial report evaluating periprocedural blood flow dynamics using 4D flow MRI before and after TAVR. Our analyses revealed that helical flow, WSS and EL in the ascending aorta were significantly decreased and EL was negatively correlated with effective orifice area index after TAVR. Our findings suggest that TAVR improves blood flow dynamics especially when a larger effective orifice area index is obtained.

Free Research Field

循環器

Academic Significance and Societal Importance of the Research Achievements

経カテーテル的大動脈弁留置術（TAVI）は、重症大動脈弁狭窄(AS）患者に対する低侵襲治療として普及してきている。しかし、TAVI後も心不全の増悪を繰り返す症例が少なからず存在する。四次元（four-dimensional; 4D）血流MRI（4D flow MRI）は、心血管系血流動態の正確な可視化と定量化を可能にする新しい血流イメージング技術である。我々は4D flow MRIを用いてTAVIによる血行動態の変化を詳細に評価した。今回の研究成果により、TAVI治療の更なる成績向上につながる礎となることが期待される。