Anticoagulated patients exhibit intact endogenous thrombin potential using ST Genesia unlike the Calibrated Automated Thrombogram

BACKGROUND: The thrombin generation (TG) assay is a feasible but labor‐intensive method for detecting global coagulation. It enables comprehensive assessment of anticoagulation, while drug‐specific assays assess only exposure. Traditionally, the Calibrated Automated Thrombogram (CAT) has been used, however the ST Genesia (Diagnostica Stago) allows automated evaluation. OBJECTIVE: We aimed to observe coagulation using the ST Genesia and compare the data with those of CAT in anticoagulated patients. PATIENTS AND METHODS: In total, 43 frozen‐thawed samples were studied using DrugScreen to assess direct oral anticoagulants (DOACs), warfarin, and low‐molecular‐weight heparin. Twenty samples (nine rivaroxaban, five apixaban, three warfarin, and three heparin) were also compared using CAT (5 pM tissue factor). RESULTS: TG reduction in DrugScreen depended on the specific drug and modestly correlated with DOAC levels (lag time R(2) = 0.36; peak R(2) = 0.50). The best correlation was observed with peak thrombin and rivaroxaban‐specified anti–activated factor X (anti‐Xa) activity (R(2) = 0.60). When comparing ST Genesia with CAT, only the results for apixaban concorded (R(2) = 0.97). Unlike CAT, ST Genesia yielded a normal endogenous thrombin potential (ETP) in 77% (24/31) activated factor X inhibitor cases, and it failed to give readouts at international normalized ratio (INR) ≥4.5 and at anti‐Xa ≥1.0 IU/mL. CONCLUSION: The ST Genesia data did not correlate with CAT, but it was independently associated with INR, anti‐Xa, and DOAC concentrations. The lag time and peak responses were similar; the major differences were that ST Genesia showed no ETP effect of DOACs and failed to give readout at high INR or anti‐Xa activity.