Updates in Anticoagulation Therapy Monitoring

Abstract

In the past six decades, heparin and warfarin were the primary anticoagulants prescribed for treatment and prophylaxis of venous thromboembolism worldwide. This has been accompanied by extensive clinical knowledge regarding dosing, monitoring, and reversal of these anticoagulants, and the resources required to do so have largely been readily available at small and large centers alike. However, with the advent of newer oral and parenteral anticoagulants such as low molecular weight heparins, factor Xa inhibitors, and direct thrombin inhibitors in recent years, new corresponding practice guidelines have also emerged. A notable shift in the need for monitoring and reversal agents has evolved as well. While this has perhaps streamlined the process for physicians and is often desirable for patients, it has also left a knowledge and resource gap in clinical scenarios for which urgent reversal and monitoring is necessary. An overview of the currently available anticoagulants with a focus on the guidelines and available tests for anticoagulant monitoring will be discussed in this article.

Keywords: anticoagulant; anticoagulation; anticoagulation monitoring; coagulation; direct oral anticoagulant; direct thrombin inhibitor; heparin; low molecular weight heparin; point of care testing; warfarin.

Figure 1

Updates to recommendations for VKA management (Based on ASH guidelines [22]). Abbreviations: VTE: venous thromboembolism; POC: point-of-care; VKA: Vitamin K antagonists; INR: international normalized ratio; DOAC: Direct oral anticoagulant; LMWH: low molecular weight heparins; UFH: unfractionated heparin.

Figure 2

Reversal of DOACs by andexanet alfa. Abbreviations used—VIIa: Factor VIIa; X, Xa: Factor X, Xa; II, IIa: Factor II, IIa; I, Ia: Factor I, Ia; DOAC: Direct oral anticoagulant; TFPI: Tissue factor pathway inhibitor; S419: Catalytic domain, active binding site with serine: Gla: membrane-binding domain N-terminal γcarboxyglutamic acid; A419: Replacement of catalytic domain, active binding site with alanine.