The impact of ECPELLA on haemodynamics and global oxygen delivery: a comprehensive simulation of biventricular failure

Background: ECPELLA, a combination of veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) and Impella, a percutaneous left ventricular (LV) assist device, has emerged as a novel therapeutic option in patients with severe cardiogenic shock (CS). Since multiple cardiovascular and pump factors influence the haemodynamic effects of ECPELLA, optimising ECPELLA management remains challenging. In this study, we conducted a comprehensive simulation study of ECPELLA haemodynamics. We also simulated global oxygen delivery (DO₂) under ECPELLA in severe CS and acute respiratory failure as a first step to incorporate global DO₂ into our developed cardiovascular simulation.

Methods and results: Both the systemic and pulmonary circulations were modelled using a 5-element resistance‒capacitance network. The four ventricles were represented by time-varying elastances with unidirectional valves. In the scenarios of severe LV dysfunction, biventricular dysfunction with normal pulmonary vascular resistance (PVR, 0.8 Wood units), and biventricular dysfunction with high PVR (6.0 Wood units), we compared the changes in haemodynamics, pressure-volume relationship (PV loop), and global DO₂ under different VA-ECMO flows and Impella support levels.

Results: In the simulation, ECPELLA improved total systemic flow with a minimising biventricular pressure-volume loop, indicating biventricular unloading in normal PVR conditions. Meanwhile, increased Impella support level in high PVR conditions rendered the LV-PV loop smaller and induced LV suction in ECPELLA support conditions. The general trend of global DO₂ was followed by the changes in total systemic flow. The addition of veno-venous ECMO (VV-ECMO) augmented the global DO₂ increment under ECPELLA total support conditions.

Conclusions: The optimal ECPELLA support increased total systemic flow and achieved both biventricular unloading. The VV-ECMO effectively improves global DO₂ in total ECPELLA support conditions.