Left Ventricular Assist Device Support-Induced Alteration of Mechanical Stress on Aortic Valve and Aortic Wall

The aim of this study was to evaluate the fluid dynamics in the aortic valve and proximal aorta during continuous-flow left ventricular assist device (LVAD) support using epiaortic echocardiography and vector flow mapping technology. A total of 12 patients who underwent HeartMate 3 implantation between December 2018 and February 2020 were prospectively examined. The wall shear stress (WSS) on the ascending aorta, aortic root, and aortic valve was evaluated before and after LVAD implantation. The median age of the cohort was 62 years and 17% were women. The peak WSS on the ascending aorta (Pre 1.48 [0.86-1.69] [Pascal {Pa}] vs. Post 0.33 [0.21-0.58] [Pa]; p = 0.002), aortic root (Pre 0.46 [0.31-0.58] (Pa) vs. Post 0.18 [0.12-0.25] (Pa); p = 0.001), and ventricularis of the aortic valve (Pre 1.76 [1.59-2.30] (Pa) vs. Post 0.30 [0.10-0.61] (Pa); p = 0.001) was significantly lower after LVAD implantation. No difference in WSS was observed on the fibrosa of the aortic valve (Pre 0.36 [0.22-0.53] (Pa) vs. Post 0.38 [0.38-0.52] (Pa); p = 0.850) before and after implantation. The WSS on the ascending aorta, aortic root, and ventricularis of the aortic valve leaflets was significantly altered by LVAD implantation, providing preliminary data on the potential contribution of fluid dynamics to LVAD-induced aortic insufficiency and root thrombus.