Postoperative Heparinization Monitoring by Anti-Xa is More Accurate Than by APTT after Pulmonary Endarterectomy - Role of Increased Systemic and Endothelial Production of Factor VIII

aPTT monitoring underestimates anticoagulation after PEA compared to Anti-Xa and is possibly influenced by elevated postoperative Factor VIII levels. Local Factor VIII production by thrombus endothelium may contribute to CTEPH pathogenesis.