Percutaneous Assessment and Intervention of Outflow Graft Stenosis in Left Ventricular Assist Device Patients-A Cohort Study.

Abstract

Despite progress in understanding and managing left ventricular assist device (LVAD) complications, outflow graft (OG) stenosis remains inadequately characterized. We described patients who underwent invasive percutaneous OG studies. We used a 10 and 14 mm OG three-dimensional (3D) reconstruction and computational fluid dynamics (CFD) analysis to examine the impact of OG stenosis on flow dynamics. Of the 21 LVAD patients who underwent invasive OG study (median age: 62.6 years, 81% male, 3 HeartMate 3 [HM3], 15 HeartWare [HVAD], and 3 HeartMate II [HMII]), 9 (43%) underwent OG stenting (0 HM3, 7 HVAD, and 2 HMII). Of these nine patients, two had stroke, and three expired post-OG intervention. Computational fluid dynamics analysis showed that with increasing degrees of OG stenosis, there was a rise in pressure gradient across the stenotic area, wall shear stress at the stenotic area, aortic wall shear stress, aortic root recirculation, and chaotic flow. These negative changes were more pronounced for the smaller OG. In conclusion, in our experience, the invasive hemodynamics study and OG stenting, when indicated, are safe and effective. Interestingly, the smaller OG diameter showed a worse hemodynamic response to stenosis. Further research on OG stenosis is needed to define best practices for this LVAD complication.