Acquired Von Willebrand Disease

The goal of this observational study is to learn how flow-based platelet function measured with the Total Thrombus-formation Analysis System (T-TAS) relates to early postoperative bleeding in adults undergoing cardiac surgery with cardiopulmonary bypass. The study will also evaluate how T-TAS changes during the perioperative period and how it compares with standard coagulation and platelet function tests. The main questions it aims to answer are: Is lower post-cardiopulmonary bypass T-TAS Platelet-chip (PL-chip) thrombus formation associated with increased postoperative chest tube drainage during the first 12 hours after surgery? How do T-TAS parameters change before surgery, immediately after cardiopulmonary bypass, and 24 hours after surgery? Are abnormal T-TAS results associated with blood transfusion requirements, major bleeding, re-exploration for bleeding, and length of stay in the intensive care unit and hospital? Does T-TAS provide complementary information compared with standard coagulation tests, von Willebrand factor (vWF) measurements, platelet aggregometry, and viscoelastic testing? Participants will: Undergo blood sampling at three predefined perioperative time points: before anesthesia induction, immediately after cardiopulmonary bypass and heparin reversal with protamine, and 24 hours after surgery Have T-TAS testing, standard laboratory coagulation tests, vWF testing, platelet aggregometry, and viscoelastic testing performed on collected samples Have clinical, surgical, transfusion, and postoperative bleeding data collected during their hospital stay The study is observational and does not require changes to routine clinical care or perioperative management.

The goal of this observational study is to learn how endothelial colony-forming cells (ECFCs) behave in people with von Willebrand disease (VWD), acquired von Willebrand syndrome (AVWS), and in healthy individuals.