"In Less than No Time": Feasibility of Rotational Thromboelastometry to Detect Anticoagulant Drugs Activity and to Guide Reversal Therapy

Abstract

Anticoagulant drugs (i.e., unfractionated heparin, low-molecular-weight heparins, vitamin K antagonists, and direct oral anticoagulants) are widely employed in preventing and treating venous thromboembolism (VTE), in preventing arterial thromboembolism in nonvalvular atrial fibrillation (NVAF), and in treating acute coronary diseases early. In certain situations, such as bleeding, urgent invasive procedures, and surgical settings, the evaluation of anticoagulant levels and the monitoring of reversal therapy appear essential. Standard coagulation tests (i.e., activated partial thromboplastin time (aPTT) and prothrombin time (PT)) can be normal, and the turnaround time can be long. While the role of viscoelastic hemostatic assays (VHAs), such as rotational thromboelastometry (ROTEM), has successfully increased over the years in the management of bleeding and thrombotic complications, its usefulness in detecting anticoagulants and their reversal still appears unclear.

Keywords: bleeding; heparins; oral anticoagulants; rotational thromboelastometry; thromboembolic events; thromboprophylaxis.

Figure 1

ROTEM parameters and their significance.

Figure 2

ROTEM parameters in anticoagulated patients with parenteral and oral anticoagulants. Legend: anti-FXa: anti-factor X activated; aPTT: activated partial thromboplastin time; CT: clotting time; CFT: clot formation time; ECATEM: ecarin-activated assay; HFU: unfractioned heparin; INR: international normalized ratio; LMWH: low-molecular-weight heparin; MCF: maximum clot firmness; NATEM: nonactivated thromboelastometry; PiCT: prothrombinase-induced clotting time; PT: prothrombin time; TFTEM: low tissue factor thromboelastometry; UFH: unfractionated heparin; VKAs: antivitamin K antagonists.