Coagulation pathway. We assessed the following 7 components of the coagulation cascade: (1) D-dimer, fibrin degradation product (FDP); (2) antithrombin III (antithrombin, AT), circulating inhibitor of thrombin; (3) endogenous thrombin potential (ETP), functional measure of thrombin generation in vitro; (4) thrombin-antithrombin complexes (TAT), antibodies to the thrombin-antithrombin complex, which is a measure of thrombin generation in vivo; (5) tissue factor (TF), protein needed for initiation of thrombin formation; (6) prothrombin fragment 1 + 2 (F1+2), activation peptide generated during conversion of prothrombin to thrombin; and (7) normalized activated protein C (APC) sensitivity ratio (nAPCsr), ETP with and without addition of APC, which is a measure of resistance to the enzymatic activity of APC.