Abstract
Despite improved hemocompatibility of left-ventricular assist devices (LVADs), assessment of blood damage remains mandatory in preclinical testing as standardized by ASTM-F1841. The most relevant test fluid is fresh, non-pooled human blood, but the limited volume of a standard donation requires significantly smaller loops than those commonly used with animal blood. In a recent study with porcine blood, we verified a miniaturized test loop with only 160 mL for the ASTM-conform paired testing of at least two LVADs and a static reference. Here, we validated this mini test loop for standardized assessment of blood damage with one 450-mL single donation of fresh human blood. Blood damage was assessed for HeartMate 3 and BPX-80 in 9 experiments with heparinized human blood for 6 hours. We analyzed plasma free hemoglobin, von Willebrand factor (vWF) concentration and collagen-binding functionality and calculated indices of hemolysis and vWF-ratios. Overall, we observed less blood damage compared to our previous study; however, the differences in mean indices of hemolysis and in mean normalized vWF-ratio between BPX-80 and HeartMate 3 were consistent for human blood. Thus, our mini test loop proved to be valid for preclinical standardized assessment of blood damage with only 450 mL of fresh human blood.
Highlights
IntroductionDespite continuous optimization in the development of left-ventricular assist devices (LVADs), lower degrees of hemolysis or sub-lethal red blood cell damage, shear-dependent von Willebrand factor (vWF) degradation and platelet dysfunction still impact LVAD patients and can cumulatively trigger pathways that lead to hemorrhagic and ischemic adverse events. assessment of blood damage remains mandatory for preclinical LVAD testing.Since 1997, the American Society of Testing and Materials (ASTM) standard F1841 regulates the in vitro assessment of hemolysis in continuous-flow LVADs to ensure equal testing at a clinically relevant operating point. the usage of bovine or porcine blood is a valid option, testing with fresh, nonpooled human blood will yield more relevant results. the limited volume of a single donation of fresh human blood requires significantly smaller test loops than the original ASTM standard loop commonly used with animal blood
This requires an even further miniaturized test loop, especially regarding the elevated target hematocrit of 35 ± 2% of the newly approved ASTM F1841-19, that will be mandatory for preclinical left-ventricular assist devices (LVADs) testing from July 12th 2021 onwards
The identified outliers of the BPX-80 mini test loop were most probably caused by overheating events or insufficient de-airing during the filling process with impact on increasing plasma free hemoglobin (pfHb), and we excluded
Summary
Despite continuous optimization in the development of left-ventricular assist devices (LVADs), lower degrees of hemolysis or sub-lethal red blood cell damage, shear-dependent von Willebrand factor (vWF) degradation and platelet dysfunction still impact LVAD patients and can cumulatively trigger pathways that lead to hemorrhagic and ischemic adverse events. assessment of blood damage remains mandatory for preclinical LVAD testing.Since 1997, the American Society of Testing and Materials (ASTM) standard F1841 regulates the in vitro assessment of hemolysis in continuous-flow LVADs to ensure equal testing at a clinically relevant operating point. the usage of bovine or porcine blood is a valid option, testing with fresh, nonpooled human blood will yield more relevant results. the limited volume of a single donation of fresh human blood requires significantly smaller test loops than the original ASTM standard loop commonly used with animal blood. Since 1997, the American Society of Testing and Materials (ASTM) standard F1841 regulates the in vitro assessment of hemolysis in continuous-flow LVADs to ensure equal testing at a clinically relevant operating point.. Paired testing of at least two LVADs and a static reference is mandatory for certification to overcome variabilities in donor blood and handling during testing and to monitor general blood damage over time at each test day, respectively. This requires an even further miniaturized test loop, especially regarding the elevated target hematocrit of 35 ± 2% of the newly approved ASTM F1841-19, that will be mandatory for preclinical LVAD testing from July 12th 2021 onwards.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
