The impact of direct oral anticoagulants on viscoelastic testing – A systematic review

Abstract

BackgroundIn case of bleeding patients and in acute care, the assessment of residual direct oral anticoagulant (DOAC) activity is essential for evaluating the potential impact on hemostasis, especially when a timely decision on urgent surgery or intervention is required. Viscoelastic tests are crucial in a modern goal-directed coagulation management to assess patients’ coagulation status. However, the role of viscoelastic test to detect and quantify residual DOAC plasma levels is controversially discussed. The aim of this review was to systematically summarize the evidence of viscoelastic tests for the assessment of residual DOAC activity.MethodPubMed, Embase, Scopus, and the Cochrane Library were searched for original articles investigating the effect of rivaroxaban, apixaban, edoxaban, or dabigatran plasma levels on different viscoelastic tests of the adult population from database inception to December 31, 2021.ResultsWe included 53 studies from which 31 assessed rivaroxaban, 22 apixaban, six edoxaban, and 29 dabigatran. The performance of viscoelastic tests varied across DOACs and assays. DOAC specific assays are more sensitive than unspecific assays. The plasma concentration of rivaroxaban and dabigatran correlates strongly with the ROTEM EXTEM, ClotPro RVV-test or ECA-test clotting time (CT) and TEG 6s anti-factor Xa (AFXa) or direct thrombin inhibitor (DTI) channel reaction time (R). Results of clotting time (CT) and reaction time (R) within the normal range do not reliable exclude relevant residual DOAC plasma levels limiting the clinical utility of viscoelastic assays in this context.ConclusionViscoelastic test assays can provide fast and essential point-of-care information regarding DOAC activity, especially DOAC specific assays. The identification and quantification of residual DOAC plasma concentration with DOAC unspecific viscoelastic assays are not sensitive enough, compared to recommended anti-Xa activity laboratory measurements.Systematic review registration[https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=320629], identifier [CRD42022320629].

Update on point-of-care-based coagulation treatment

“…Plättchendysfunktionen werden mithilfe von VET ebenfalls nur ungenügend erfasst, nur das für die TEG entwickelte Platelet-Mapping™ (PM) ermöglicht die grobe Abschätzung einer möglichen Plättchenfunktionsstörung [ 46 ]. Auch DOAC können mit den üblicherweise verwendeten Standard-Assays nur mit unzureichender Sensitivität und Spezifität detektiert werden [ 47 , 48 ], dafür sind DOAC-spezifische Reagenzien notwendig [ 29 ]. Die Geräte erwärmen, vergleichbar zu SGT im Labor, das zu analysierende Blut standardisiert auf 37 °C.…”

“…Zum Ausschluss einer Restheparinwirkung sollte daher, in dieser speziellen Konstellation, zusätzlich ein HEPTEM/HEP-Test durchgeführt werden. Verkürzt sich die CT im HEPTEM/HEP-Test, verglichen zum INTEM/IN-Test, kann dies als Hinweise auf eine bestehende Heparinwirkung interpretiert werden, die dann durch Protamin reversiert werden kann [ 47 ].…”

Management of patients with proximal femur fractures under DOACs

“…However, they do not provide any information on current plasma concentrations and the extent of remaining anticoagulation [ 41 ]. Viscoelastic test assays may provide fast and essential point-of-care information when DOAC-specific assays are being used but these need further refinement [ 42 ]. The identification and quantification of residual DOAC plasma concentrations with DOAC non-specific viscoelastic assays is not sensitive enough compared to recommended and calibrated anti-Xa laboratory measurements [ 42 ].…”

Direct oral anticoagulants in trauma patients

“…Visco-elastic tests (VETs) for the detection of DOACs in emergency scenarios have gained increasing attention over the last years [27,28 ▪ ,29–31]. However, it has been consistently demonstrated, that the initiation phase of the coagulation process (the clotting time; CT [ROTEM] or r-time [TEG]) of standard visco-elastic assays is not sensitive enough to identify a residual or clinically relevant DOAC plasma concentration [27,29,32]. For TEG6s a DOAC specific cartridge was developed, and first promising results have been published [33].…”