Viscoelastic monitoring of direct oral anticoagulants (DOAC)

Abstract

The management of procedures at risk of major or critical bleeding in patients treated with direct oral anticoagulants (DOAC) is challenging, making urgent monitoring to detect and quantify residual effects, optimal for accurate clinical decision making. Conventional coagulation tests such as prothrombin time and activated partial thromboplastin time can be used as screening tests to detect the non-specific presence of DOAC, but do not correlate well with plasma concentrations. Quantitative methods such as diluted thrombin time for direct thrombin inhibitors and calibrated anti-Xa assays or activated FX inhibitors provide limited therapeutic monitoring. Viscoelastic analysis offers a reliable option for urgent assessment of the presence of DOAC. The tests and parameters that have been shown to be useful in differentiating between types of DOAC are those that evaluate the kinetics and generation of thrombin with modification of the reagents, and correlate the times obtained with residual plasma concentrations. Viscoelastic monitoring with specific assays (Russell's Viper Venom and Ecarin) provides a rapid and reliable tool with greater sensitivity than conventional laboratory tests in urgent procedures with critical bleeding risk, enabling a quantitative assessment of the residual effect of a DOAC and its possible therapeutic reversal. Although clinical practice guidelines do not currently support the widespread use of viscoelastic testing for DOAC monitoring due to limited evidence, these tests provide a global hemostatic perspective and have the advantage of speed, individualization, and the possibility of quantitative monitoring. Research and further distribution of rapid and accurate viscoelastic-specific monitoring devices should be encouraged to improve clinical decision making and patient outcomes.