Rapid point-of-care detection and classification of direct-acting oral anticoagulants with the TEG 6s: Implications for trauma and acute care surgery

Abstract

BACKGROUND The trauma patient on direct oral anticoagulant (DOAC) therapy preinjury presents a challenge in trauma and acute care surgery. Our understanding of these patients is extrapolated from vitamin K antagonists. However, DOACs have different mechanisms of action, effects on laboratory coagulation assays, and reversal strategies. Rapid identification of DOACs in the blood will allow timely reversal of factor Xa inhibitors and direct thrombin inhibitors when necessary. The present study evaluated viscoelastic testing to detect and classify DOACs in patient blood samples. METHODS This observational, prospective, open-label, multicenter study used point-of-care viscoelastic testing to analyze blood samples taken from patients with and without DOAC treatment, and healthy volunteers. Antifactor Xa and direct thrombin inhibition (DTI) assays were used to establish reference ranges for viscoelastic testing parameters on the TEG 6s system. These ranges were applied to produce a DOAC identification algorithm for patient blood samples. Internal consistency of the measurements, as well as algorithm sensitivity and specificity, was evaluated. RESULTS Using the TEG 6s system, the R parameter reference range was 0.6 minutes to 1.5 minutes for the Antifactor Xa assay and 1.6 minutes to 2.5 minutes for the DTI assay. Our identification algorithm using these ranges for 2.5 minutes or less has sensitives of 98.3% and 100% for factor Xa inhibitor and direct thrombin inhibitor detection, respectively. Specificity was 100%. Both classes of DOAC were detectable, even when samples were collected during the “trough” between doses of medication. CONCLUSION Point-of-care viscoelastic testing with TEG 6s can detect and classify DOACs with high sensitivity and specificity. This tool can be used to better determine the need for reversal in trauma and acute care surgery patients and guide optimal surgical timing in the acute setting. LEVEL OF EVIDENCE Prognostic and epidemiological study, level II.

Comparison of three common whole blood platelet function tests for in vitro P2Y12 induced platelet inhibition

“…Thromboelastography (TEG ® ) (Haemonetics, Braintree, MA, USA), Multiplate ® (Roche Diagnostics, Rotkreuz, Switzerland), PFA-100/PFA-200 (Siemens, Munich, Germany) and VerifyNow ® (Accumetrics, San Diego, CA, USA) systems are the most frequently studied. TEG ® PlateletMapping ® has been shown to be predictive of bleeding and thrombotic risk in patients undergoing PCI [7,8], cardiac [9][10][11], and non-cardiac surgery [11,12]; and the TEG ® DOAC cartridge can detect and classify direct oral anticoagulants with high specificity and sensitivity [13]. The clinical value of Multiplate ® in patients undergoing PCI or cardiac surgery [14][15][16], and VerifyNow ® in patients undergoing cardiac surgery [17,18] has also been established.…”

Direct Oral Anticoagulants and Timing of Hip Fracture Surgery

“…This involves daily testing and delaying surgery until an arbitrary value, such a 30 μg/L, 50 μg/L or 80 μg/L of DOAC concentration, is reached. Thromboelastography (TEG) parameters have been used to accurately assess the presence of DOACs in well, nonsurgical populations without correlation to plasma drug levels [ 19 ]. Both may be used as rapid bedside tools in the future; however, uncertainty still remains around whether delay of surgery is advantageous.…”

“…Factor Xa levels are possible to perform with patients taking apixaban, rivaroxaban and edoxaban, but how they relate to surgical timing in hip fracture unknown. Several options are available for reversal, but they are expensive and seldom utilised given the subacute nature of hip fracture surgery [18,19].…”

Diagnosis and Treatment of Trauma-Induced Coagulopathy by Viscoelastography

“…117,118 ) In addition, a unique investigational direct oral anticoagulant (DOAC) cartridge for both direct thrombin inhibitors and anti-factor Xa inhibitors has shown a high level of sensitivity and specificity in determining activity of these agents in an experimental setting. 114 This new ability to determine the activity of the DOACs has significant implications, particularly for trauma patients who are on these agents. With the advent of reversal agents, idarucizumab and andexanet alfa, these tests may find rapid adoption in the trauma setting.…”