Abstract 14174: Holistic Optimization of Surgical Implantation Configurations Reduce Thrombogenicity of LVAD Therapy

IntroductionLeft ventricular assist devices (LVAD) play an increasingly important role for the medical-therapy refractory end-stage heart failure (HF) patient population, in the context of stagnant donor heart availability. Thromboembolic and hemorrhagic complications such as strokes, however, remain high, and in some cases have seen increased incidence. There are a lack of guidelines governing LVAD surgical implantation configurations, which have been shown to have a strong influence on the thrombogenicity of LVAD therapy.MethodsWe use a platelet-focused approach to simulate the thrombogenicity of virtual LVAD implantations under a wide range of clinically-relevant parameters. We investigate the hemodynamic microenvironment in the LVAD inflow (left ventricle inflow cannula angulation, inflow cannula insertion depth, left ventricle size) and outflow (outflow graft anastomoses angles, outflow graft diameters and partial intermittent aortic valve opening) regions, analyzing platelet biomechanics. Rigorous statistical methods are used to analyze hundreds of thousands of platelet trajectories to characterize thrombogenic indices such as residence time (RT), shear history (SH) and shear loading (SL) for platelet activation.ResultsAn unfavorable hemodynamic microenvironment in the left ventricle due to malangulation of the inflow cannula predisposes platelets, to activate and agglomerate before entering the LVAD. Similarly, small left ventricles pose a markedly elevated thrombosis risk, especially in the presence of deep inflow cannula insertion depths. These intraventricular hemodynamics, coupled with non-optimal outflow graft anastomosis angles, represent an additional risk of stroke, via flow-mediated platelet activation. Thrombogenic risk can be mitigated to a significant extent by optimizing surgical configurations and patient management strategies for LVAD speed, conducive to intermittent aortic valve flow.ConclusionsThe novel comprehensive simulation approach followed in this study to evaluate thrombogenicity via platelet-based metrics can be implemented in surgical implantation guidelines to reduce the rate of thromboembolic complications, improving long-term outcomes of LVAD therapy.