Abstract
BackgroundDetermination of anticoagulant therapy is of pronounced interest in emergency situations. However, routine tests do not provide sufficient insight. This study was performed to investigate the impact of anticoagulants on the results of viscoelastometric assays using the ClotPro device.MethodsThis prospective, observational study was conducted in patients receiving dabigatran, factor Xa (FXa)-inhibitors, phenprocoumon, low molecular weight heparin (LMWH) or unfractionated heparin (UFH) (local ethics committee approval number: 17–525-4). Healthy volunteers served as controls. Viscoelastometric assays were performed, including the extrinsic test (EX-test), intrinsic test (IN-test) Russel’s viper venom test (RVV-test), ecarin test (ECA-test), and the tissue plasminogen activator test (TPA-test).Results70 patients and 10 healthy volunteers were recruited. Clotting time in the EX-test (CTEX-test) was significantly prolonged versus controls by dabigatran, FXa inhibitors and phenprocoumon. CTIN-test was prolonged by dabigatran, FXa inhibitors and UFH. Dabigatran, FXa inhibitors and UFH significantly prolonged CTRVV-test in comparison with controls (median 200, 207 and 289 vs 63 s, respectively; all p < 0.0005). Only dabigatran elicited a significant increase in CTECA-test compared to controls (median 307 vs 73 s; p < 0.0001). CTECA-test correlated strongly with dabigatran plasma concentration (measured by anti-IIa activity; r = 0.9970; p < 0.0001) and provided 100% sensitivity and 100% specificity for detecting dabigatran. Plasma concentrations (anti-XA activity) of FXa inhibitors correlated with CTRVV-test (r = 0.7998; p < 0.0001), and CTRVV-test provided 83% sensitivity and 64% specificity for detecting FXa inhibitors.ConclusionsIn emergency situations, ClotPro viscoelastometric assessment of whole-blood samples may help towards determining the presence and type of anticoagulant class that a patient is taking.Trial registrationGerman clinical trials database ID: DRKS00015302.
Highlights
Determination of anticoagulant therapy is of pronounced interest in emergency situations
The last intake of anticoagulant medication was at a median of 3.75 h before taking the blood sample in patients treated with dabigatran, 6.00 h among those receiving factor Xa (FXa) inhibitors, and 3.25 h in patients on low molecular weight heparin (LMWH)
In the Receiver operating characteristic (ROC) analysis, the optimal CTEX-test cut-off for FXa-inhibitor detection was determined as 69 s
Summary
Determination of anticoagulant therapy is of pronounced interest in emergency situations. In an unknown patient with emergency bleeding, it may be necessary to determine the presence and type of anticoagulant therapy by performing coagulation tests. The results of standard laboratory tests (e.g. international normalized ratio [INR], activated partial thromboplastin time [aPTT]), as well as standard viscoelastic tests (e.g. EXTEM clotting time (CT), TEG R-time), are affected by anticoagulant drugs [11,12,13,14]. These routine tests do not readily provide sufficient insight to determine exactly which drug a patient is taking. There is a need for specific diagnostic tools suitable for point-of-care use in emergency situations [15, 16]
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