Interrupting anticoagulation in patients with nonvalvular atrial fibrillation.

Three target-specific oral anticoagulants (TSOACs)-dabigatran, rivaroxaban, and apixaban-have been approved by the FDA to reduce the risk of stroke and systemic embolism in patients with nonvalvular atrial fibrillation; however, no agents are currently approved to reverse the anticoagulant effects of these TSOACs in cases of active bleeding. This review discusses the benefits and risks of these TSOACs from a clinician's perspective, with a focus on the interruption of treatment for either elective or emergent surgery, monitoring, and reversal of anticoagulation. Available coagulation assays are not ideal for monitoring the effects of TSOACs and do not provide reliable quantitative measurement of their anticoagulant effects. When necessary, activated partial thromboplastin time (aPTT) may provide qualitative information on dabigatran, and prothrombin time (PT) may provide qualitative assessment of the presence of the factor Xa inhibitors, rivaroxaban and apixaban. Current recommendations for reversal of TSOACs are based largely on limited and sometimes conflicting data from in vitro or in vivo animal models, and clinical experience with these recommendations is also limited. Methods that have been investigated for effectiveness for reversal of the pharmacodynamic effects of the TSOACs include dialysis, activated charcoal, prothrombin complex concentrate (PCC), and recombinant activated factor VII. It is important to note that even within a class of anticoagulant drugs, compounds respond differently to reversal agents; therefore, recommendations for one agent should not be extrapolated to another, even if they are from the same therapeutic class. New antidotes are being explored, including a mouse monoclonal antibody to dabigatran; andexanet alfa, a potential universal factor Xa inhibitor reversal agent; and a synthetic small molecule (PER977) that may be effective for the reversal of factor Xa inhibitors and direct thrombin inhibitors. Given the short half-lives of TSOACs, watchful waiting, rather than reversal, may be the best approach in some circumstances.