Assessing the Hemodynamic Impact of Anterior Leaflet Laceration in Transcatheter Mitral Valve Replacement: An in silico Study

Keshav Kohli; Zhenglun Alan Wei; Vahid Sadri; Andrew W Siefert; Philipp Blanke; Emily Perdoncin; Adam B Greenbaum; Jaffar M Khan; Robert J Lederman; Vasilis C Babaliaros; Ajit P Yoganathan; John N Oshinski

doi:10.3389/fcvm.2022.869259

Assessing the Hemodynamic Impact of Anterior Leaflet Laceration in Transcatheter Mitral Valve Replacement: An in silico Study

Front Cardiovasc Med. 2022 Jun 9:9:869259. doi: 10.3389/fcvm.2022.869259. eCollection 2022.

Authors

Affiliations

¹ Wallace H. Coulter Department of Biomedical Engineering at the Georgia Institute of Technology and Emory University, Atlanta, GA, United States.
² Department of Biomedical Engineering, University of Massachusetts Lowell, Lowell, MA, United States.
³ Department of Radiology, St. Paul's Hospital, The University of British Columbia, Vancouver, BC, Canada.
⁴ Structural Heart and Valve Center, Emory University Hospital, Atlanta, GA, United States.
⁵ Cardiovascular Branch, Division of Intramural Research, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, United States.
⁶ Department of Radiology and Imaging Science, Emory University School of Medicine, Atlanta, GA, United States.

Abstract

Background: A clinical study comparing the hemodynamic outcomes of transcatheter mitral valve replacement (TMVR) with vs. without Laceration of the Anterior Mitral leaflet to Prevent Outflow Obstruction (LAMPOON) has never been designed nor conducted.

Aims: To quantify the hemodynamic impact of LAMPOON in TMVR using patient-specific computational (in silico) models.

Materials: Eight subjects from the LAMPOON investigational device exemption trial were included who had acceptable computed tomography (CT) data for analysis. All subjects were anticipated to be at prohibitive risk of left ventricular outflow tract (LVOT) obstruction from TMVR, and underwent successful LAMPOON immediately followed by TMVR. Using post-procedure CT scans, two 3D anatomical models were created for each subject: (1) TMVR with LAMPOON (performed procedure), and (2) TMVR without LAMPOON (virtual control). A validated computational fluid dynamics (CFD) paradigm was then used to simulate the hemodynamic outcomes for each condition.

Results: LAMPOON exposed on average 2 ± 0.6 transcatheter valve cells (70 ± 20 mm² total increase in outflow area) which provided an additional pathway for flow into the LVOT. As compared to TMVR without LAMPOON, TMVR with LAMPOON resulted in lower peak LVOT velocity, lower peak LVOT gradient, and higher peak LVOT effective orifice area by 0.4 ± 0.3 m/s (14 ± 7% improvement, p = 0.006), 7.6 ± 10.9 mmHg (31 ± 17% improvement, p = 0.01), and 0.2 ± 0.1 cm² (17 ± 9% improvement, p = 0.002), respectively.

Conclusion: This was the first study to permit a quantitative, patient-specific comparison of LVOT hemodynamics following TMVR with and without LAMPOON. The LAMPOON procedure achieved a critical increment in outflow area which was effective for improving LVOT hemodynamics, particularly for subjects with a small neo-left ventricular outflow tract (neo-LVOT).

Keywords: LAMPOON; computational fluid dynamics (CFD); computed tomography (CT); left ventricular outflow tract obstruction; neo-LVOT; personalized computational modeling; transcatheter mitral valve replacement (TMVR).