Influence of TF concentration on the thrombographic assessment of oral anticagulation. Thrombin generation with VKA anticoagulated plasma (George King Biomedical Inc, Overland Park, Kansas, USA ) and rivaroxaban-spiked normal plasma was performed with triggering reagent containing 4 μM phospholipids and 1, 5, and 20 pM TF as described . At decreasing TF, thrombin generation decreases; i.e. longer lag time and decreased peak height and AUC. At a TF concentration of 1 pM, thrombin generation in VKA- and rivaroxaban anticoagulated plasma is unnoticed at high anticoagulant levels, while detectable at 5 and 20 pM. Reversal of oral anticoagulation can be achieved, e.g., by PCC (see Figure 6).