Gradient and pressure recovery of a self-expandable transcatheter aortic valve depends on ascending aorta size: In vitro studyCentral MessagePerspective
Milad Samaee, PhD,
Hoda Hatoum, PhD,
Michael Biersmith, MD,
Breandan Yeats, MS,
Shelley C. Gooden, MS,
Vinod H. Thourani, MD,
Rebecca T. Hahn, MD,
Scott Lilly, MD, PhD,
Ajit Yoganathan, PhD,
Lakshmi Prasad Dasi, PhD
Affiliations
Milad Samaee, PhD
Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga
Hoda Hatoum, PhD
Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga
Michael Biersmith, MD
Department of Surgery, Ohio State University, Columbus, Ohio
Breandan Yeats, MS
Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga
Shelley C. Gooden, MS
Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga
Vinod H. Thourani, MD
Department of Cardiovascular Surgery, Marcus Valve Center, Piedmont Heart Institute, Atlanta, Ga
Rebecca T. Hahn, MD
Division of Cardiology, Columbia University Medical Center, New York, NY
Scott Lilly, MD, PhD
Department of Surgery, Ohio State University, Columbus, Ohio
Ajit Yoganathan, PhD
Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga
Lakshmi Prasad Dasi, PhD
Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga; Address for reprints: Lakshmi Prasad Dasi, PhD, Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Technology Enterprise Park (TEP), 387 Technology Circle, Office 232, Atlanta, GA 30313-2412.
Objective: In this study we aimed to understand the role of interaction of the Medtronic Evolut R transcatheter aortic valve with the ascending aorta (AA) by evaluating the performance of the valve and the pressure recovery in different AA diameters with the same aortic annulus size. Methods: A 26-mm Medtronic Evolut R valve was tested using a left heart simulator in aortic root models of different AA diameter (D): small (D = 23 mm), medium (D = 28 mm), and large (D = 34 mm) under physiological conditions. Measurements of pressure from upstream to downstream of the valve were performed using a catheter at small intervals to comprehensively assess pressure gradient and pressure recovery. Results: In the small AA, the measured peak and mean pressure gradient at vena contracta were 11.5 ± 0.5 mm Hg and 7.8 ± 0.4 mm Hg, respectively, which was higher (P < .01) compared with the medium (8.1 ± 0.4 mm Hg and 5.2 ± 0.4 mm Hg) and large AAs (7.4 ± 1.0 mm Hg and 5.4 ± 0.6 mm Hg). The net pressure gradient was lower for the case with the medium AA (4.1 ± 1.2 mm Hg) compared with the small AA (4.7 ± 0.8 mm Hg) and large AA (6.1 ± 1.4 mm Hg; P < .01). Conclusions: We have shown that small and large AAs can increase net pressure gradient, because of the direct interaction of the Medtronic Evolut R stent with the AA (in small AA) and introducing higher level of turbulence (in large AA). AA size might need to be considered in the selection of an appropriate device for transcatheter aortic valve replacement.
