P23: Preservation of Pulsatility with Universal Ventricular Assist Device: An In Vitro Assessment of Biventricular Support

Abstract

Objective: The objective of this study was to assess the ability and performance of the Universal Ventricular Assist Device (UVAD) to maintain pulsatility when used as a biventricular assist device (BVAD) through an in vitro experiment utilizing a pulsatile biventricular mock circulatory loop. Methods: The UVAD pumps were evaluated in a dual configuration (BVAD) in the simulated circulatory model under conditions of left heart failure (HF), right HF, and moderate/severe biventricular HF. Measurements of total flow, pulse pressure in the aorta, pulse augmentation factor (PAF), energy-equivalent pressure (EEP), and surplus hemodynamic energy (SHE) were taken at various pump speeds to assess pulsatility. Results: The association between the maximum and minimum pressures and various parameters of the pump was determined during the cardiac cycle. It was observed that the pulse pressure increased across all heart conditions (Figure 1). The PAF ranged from 17-35% in healthy, LHF, RHF, and mild BHF conditions, with the highest PAF, 90%, being observed in the severe BHF condition. EEP correlated with LVAD flow in all groups (R2 = 0.87-0.97) and increased from baseline in all cases. SHE peaked at approximately 5-6 L/min of LVAD support and tended to dissipate surplus energy at higher LVAD pump flow. The greatest decrease in SHE from baseline, 53%, was observed in the mild BHF condition with the highest levels of left ventricular assist device (LVAD) and right ventricular assist device (RVAD) support. Conclusion: The UVAD successfully demonstrated the ability to preserve pulsatility in vitro, and to optimize cardiac output, as an isolated circulatory support device option (RVAD or LVAD), and when used for BVAD support.Figure 1. The relationships between LVAD/RVAD pump flow and aortic pulse pressure/PAF/EEP/SHE in each heart condition. LVAD, left ventricular assist device; RVAD, right ventricular assist device; AoP, aortic pressure; EEP, energy-equivalent pressure; SHE, surplus hemodynamic energy.