ristocetin and Gastrointestinal-Hemorrhage

Heyde's syndrome is characterized by iron deficiency anemia due to gastrointestinal bleeding and calcific aortic stenosis. Patients with this syndrome have a bleeding diathesis due to a loss of the largest multimers of von Willebrand factor (vWF). Here we present a case of Heyde's syndrome diagnosed with abnormal closure times and normal vWF Ristocetin cofactor activity (vWF:Rco). In this case, a 79-year-old man with known aortic stenosis and recurrent gastrointestinal bleeding was cured of a life-threatening hemorrhage after the replacement of his stenotic aortic valve. Factor VIII activity (1.53  IU/ml), vWF antigen (1.26  IU/ml), vWF:Rco (1.11  IU/ ml), and the ratio of vWF antigen/vWF:Rco (0.88) were all within normal limits. Instead, to prove a defect in platelet aggregation, closure times measured with collagen/ADP and collagen/epinephrine were abnormal (>300  s). Postoperatively, these closure times normalized. What is unique about our current report is that we measured both vWF:Rco and closure times, the two readily available assays in most coagulation laboratories. vWF:Rco is a standard assay for measuring platelet activity but may miss defects in platelet aggregation that are only seen under high shear stress. As the closure times can detect such defects, it is perhaps more representative than traditional assays, and in situations such as our case, closure times may be the only method by which subtle abnormalities in vWF function could be detected.

Topics: Adenosine Diphosphate; Aged; Aortic Valve; Aortic Valve Stenosis; Blood Coagulation Tests; Collagen; Epinephrine; Factor VIII; Gastrointestinal Hemorrhage; Humans; Male; Platelet Aggregation; Ristocetin; von Willebrand Diseases; von Willebrand Factor

Topics: Blood Coagulation Tests; Factor VIII; Gastrointestinal Hemorrhage; Humans; Platelet Adhesiveness; Ristocetin; von Willebrand Diseases

Topics: Adenosine Diphosphate; Aged; Blood Cell Count; Blood Coagulation Disorders; Blood Coagulation Tests; Blood Platelets; Blood Proteins; Collagen; Electrophoresis; Female; Fibrinogen; Gastrointestinal Hemorrhage; Humans; Male; Microscopy, Electron; Middle Aged; Platelet Aggregation; Ristocetin; Sialic Acids; Stimulation, Chemical; Thrombocytopenia