Abstract 13632: The Optimization of Mechanical Circulatory Support Device Combination Considering Ventricular Load in Biventricular Failure Condition: A Simulation Study

Abstract

Backgrounds: Recently, the combination of Impella, a percutaneous transvalvular left ventricular assist device, and veno-arterial extracorporeal membrane oxygenation (ECMO) have improved the survival rate of cardiogenic shock by its powerful hemodynamic support effect. Meanwhile, the optimal flow control of those devices remains unclear, especially in biventricular failure (BVF). In this study, we established the mathmatical cardiovasular simulation model, and evaluated how the combination therapy impacts both right (RV) and left (LV) ventricular loading. Methods: We used SimulinkⓇ (Mathworks, Inc.) for the simulation. Both the systemic and pulmonary circulation were modeled by using 5-element resistance-capacitance net-work. Four cardiac chambers were represented by time-varying elastance with unidirectional valves (Fig. 1). In LV dysfunction (LV end-systolic elastace was set at low level: 0.4 mmHg/ml), we compared the changes of right (RAP) and left (LAP) atrial pressure, as the marker of ventricular loading, under various RV function and Impella and ECMO flows. Results: Impella slightly increased RAP and reduced LAP regardless of RV systolic function (Fig. 2). In high pulmonary vascular resistance (PVR), the increase of Impella flow augumented RAP, while Impella could not be up-titrated more than 2.8 L/min due to LV suction (Fig. 3). In BVF with high PVR, ECMO decreased RAP and increased LAP in each Impella flow (Fig. 4). Higher ECMO and Impella flows rendered LV extremely small, induced suction, and increased RV preload and RAP. Conclusion: PVR is the major determinant of stable Impella support without inducing RV loading and LV suction. In BVF with high PVR, ECMO reduced RV loading, while decreased LV filling and induced LV suction by Impella. The preemptive simulation study for an individual patient may help the optimal use of mechanical circulatory support device to maximize RV and LV unloading with improving hemodynamics.