Comparison of the Hemocompatibility of an Axial and a Centrifugal Left Ventricular Assist Device in an In Vitro Test Circuit

Abstract

Background: Hemocompatibility of left ventricular assist devices is essential for preventing adverse events. In this study, we compared the hemocompatibility of an axial-flow (Sputnik) to a centrifugal-flow (HeartMate 3) pump. Methods: Both pumps were integrated into identical in vitro test circuits, each filled with 75 mL heparinized human blood of the same donor. During each experiment (n = 7), the pumps were operated with equal flow for six hours. Blood sampling and analysis were performed on a regular schedule. The analytes were indicators of hemolysis, coagulation activation, platelet count and activation, as well as extracellular vesicles. Results: Sputnik induced higher hemolysis compared to the HeartMate 3 after 360 min. Furthermore, platelet activation was higher for Sputnik after 120 min onward. In the HeartMate 3 circuit, the platelet count was reduced within the first hour. Furthermore, Sputnik triggered a more pronounced increase in extracellular vesicles, a potential trigger for adverse events in left ventricular assist device application. Activation of coagulation showed a time-dependent increase, with no differences between both groups. Conclusions: This experimental study confirms the hypothesis that axial-flow pumps may induce stronger hemolysis compared to centrifugal pumps, coming along with larger amounts of circulating extracellular vesicles and a stronger PLT activation.

Impella 5.5 as a bridge to heart transplantation: Waitlist outcomes in the United States

“…While a direct comparison was not feasible, our findings further illustrate advantages of Impella 5.5 support over VA‐ECMO when applicable. Device related shear‐stress, subsequent hemolysis, and its end‐organ sequelae including renal failure have long been of concern in patients with prolonged support with axial LVADs 25,26 . However, a recent head to head comparison of hemocompatibility between the Impella 5.5 and the Centrimag demonstrated comparable hemocompatibility and reduced generation of shear‐related microparticles in the Impella 5.5, ameliorating concern that its high rotational speed would increase shear stress 17 .…”

“…Device related shear-stress, subsequent hemolysis, and its end-organ sequelae including renal failure have long been of concern in patients with prolonged support with axial LVADs. 25,26 However, a recent head to head comparison of hemocompatibility between the Impella 5.5 and the Centrimag demonstrated comparable hemocompatibility and reduced generation of shear-related microparticles in the Impella 5.5, ameliorating concern that its high rotational speed would increase shear stress. 17 In addition, transvalvular LV unloading afforded by the Impella 5.5 has in fact been shown to improve RV adaptation and unloading, ultimately relieving venous congestion and cardio-pulmonary-renal axis dysfunction in patients with biventricular cardiogenic shock.…”