Société de Biomécanique Young Investigator Award: In silico study of the effects of Left Ventricular Assist Device inflow cannula design and pump unsteady flow on left ventricular hemodynamics.

Advances in left ventricular assist devices (LVADs) have improved hemocompatibility and durability, making this technology a viable lifesaving long-term treatment option for individuals with advanced heart failure (HF). Despite these improvements, the rate of stroke in LVAD patients remains high. The inflow cannula design impacts Left Ventricle (LV) hemodynamics, potentially creating thrombogenic flow patterns. This research aims to analyze the LV hemodynamic differences of two LVAD inflow cannula designs: one protruding 16 mm into the LV (HeartMate III, HM3) and the other flush with the myocardium (Evaheart 2, EVA2). Both inflow cannulae were virtually implanted into the apex of a 3D reconstructed LV from a HF patient. The aortic valve (AV) remained closed and a flow rate of 5 L/min was maintained using pulsatile waveforms adapted to each pumps' characteristics. Computational fluid dynamic simulation analysis focuses on Eulerian and Lagrangian metrics to estimate LV washout and quantify blood stasis. The EVA2 high flow rate pulsatility, related to the inherently high dependency on preload designed into the pump performance, improves LV washout especially near the closed AV and the flush cannula prevents stasis at the apex. However, the evaluation of the effect of pump characteristics and cannula design separately demonstrated the dominant role of the pump characteristics (i.e. the H-Q curves) in reducing stasis.