Von Willebrand Factor Activation Assays Predict Bleeding And Other Hemocompatibility-Related Adverse Events In Patients With CF-LVAD.

Bleeding and hemocompatibility-related adverse events (HRAEs - bleeding, neurological event, stroke, arterial thrombosis, pump thrombosis, and death) remain significant in LVAD patients; changes in coagulation homeostasis, mainly due to von Willebrand Factor (vWF) structural and functional changes induced by mechanical support have been considered a major player in these adverse events. However, the specific mechanisms and the clinical correlation between coagulation profile parameters and clinical outcomes are not yet completely clarified. We hypothesized that coagulation profile parameters analyzing vWF functionality would be associated with bleeding events and HRAE. We prospectively studied patients on LVAD support at our Institution from 2019 to 2021; blood samples were collected, and an in-depth pilot analysis of their coagulation profile was assessed with vWF assays, coagulation factor assays, platelet function analysis, and routine laboratory tests. Baseline information of all patients including demographic characteristics and clinical outcomes along with the time on support were collected from electronic medical records. The primary endpoint in our analysis was any bleeding. The secondary endpoint was a composite of all HRAEs. The discriminatory power of predictors for outcomes was determined by the area under the ROC curve (AUC). Of the 53 LVAD patients studied (13=HVAD, 40=HMIII), 24 (45.3%) experienced bleeding events; and 34 (64.2%) met the criteria for our secondary composite outcomes. vWF multimer assays were not associated with bleeding or HRAE. No significant differences were evident in clinical characteristics, time on support, or type of LVAD, between patients who experienced bleeding or HRAEs. Among coagulation profile parameters, patients with bleeding events had a higher measured vWF Collagen Binding Activity (vWF:CB) [183.0 (164.0, 218.0) vs 137.0 (106.0, 175.0) IU/dl, p=0.01] while patients with HRAE had higher levels of vWF propeptide [193.0 (167.0, 241.0) vs 149.5 (115.0, 175.0) IU/dl, p= 0.045]. vWF:CB and vWF propeptide had good performances in predicting bleeding and HRAEs complications, respectively (Figure 1). In this pilot study, our findings suggest that vWF activation rather than cleavage predict bleeding events and HRAEs. Coagulation profile measurements on LVAD patients may provide insight into bleeding risks and HRAEs thus translating into personalized care and outcome improvement. [ABSTRACT FROM AUTHOR]