BACKGROUND: Left ventricular assist devices (LVADs) have been utilized to maintain the circulatory demands of patients with end-stage heart failure. Despite their positive impact, hemocompatibility-related adverse events remain a major challenge. The aim of this study is to compare in vitro hemocompatibility performance between the HeartMate 2 (HM2) and HeartMate 3 (HM3) pumps by assessing device-induced blood damage in an in vitro circulatory loop.

METHODS: Fresh healthy human blood was circulated for 4 h in a circulatory loop assisted by an HM2 or HM3 pump at a flow rate of 4.5 L/min and a pressure head of 75 mmHg. Hourly blood samples were collected for analysis of hemolysis, platelet activation, platelet receptor shedding, and high molecular weight multimer (HMWM) degradation of von Willebrand factor (VWF).

RESULTS: The data from the hourly blood samples showed that the HM3 pump caused significantly lower levels of hemolysis, platelet activation, platelet receptor shedding, and HMWM degradation of VWF compared to the HM2 pump.

CONCLUSION: The HM3 exhibited superior overall hemocompatibility to the HM2, underscoring the advantages of the fully magnetically levitated centrifugal pump design in the HM3 compared to the mechanical bearing-supported axial pump design of the HM2.