Journal of thrombosis and thrombolysis
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J. Thromb. Thrombolysis · Feb 2016
ReviewDecision-making about the use of non-vitamin K oral anticoagulant therapies for patients with atrial fibrillation.
Until recently, vitamin K antagonists, warfarin being the most commonly used agent in the United States, have been the only oral anticoagulant therapies available to prevent stroke in patients with atrial fibrillation (AF). In the last 5 years four new, non-vitamin K oral anticoagulants, the so-called NOACs or novel oral anticoagulants, have come to market and been approved by the Federal Drug Administration. Despite comparable if not superior efficacy in preventing AF-related stroke, and generally lower risks of major hemorrhage, particularly intracranial bleeding, the uptake of these agents has been slow. ⋯ Three reversal agents, idarucizumab, andexanet alfa, and aripazine, have already progressed to human studies and show great promise as either antidotes for specific drugs or as universal reversal agents. The availability of these reversal agents will likely increase the clinical use of the non-vitamin K oral anticoagulants. In light of the many complex and nuanced issues surrounding the choice of an optimal anticoagulant for any AF patient, a patient-centered/shared decision-making approach will be useful.
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J. Thromb. Thrombolysis · Feb 2016
ReviewWhy develop antidotes and reversal agents for non-vitamin K oral anticoagulants?
Over the past several years, non-vitamin K oral anticoagulants (NOACs) have been introduced into clinical practice for the treatment of venous thromboembolism and prevention of stroke in patients with nonvalvular atrial fibrillation. Clinical trials have shown these agents to have similar or less risk of major bleeding as compared to warfarin therapy. ⋯ However, there are situations where urgent reversal of NOAC anticoagulation would be desirable. The following review focuses on the outcomes and management strategies for patients experiencing a major bleed with warfarin or NOAC agents and describes the rationale for the development of therapies capable of targeted NOAC-reversal.
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J. Thromb. Thrombolysis · Feb 2016
Clinical TrialStandardized use of novel oral anticoagulants plasma level thresholds in a new thrombolysis decision making protocol.
Acute ischemic stroke (AIS) patients receiving non-vitamin-K antagonist oral anticoagulants (NOAC) are commonly excluded from thrombolytic therapy, as interpretation of coagulation tests remains unclear. We aimed to investigate the applicability of a novel institutional protocol for thrombolysis based on current expert recommendations and NOAC specific coagulation assessment. We included hospitalized AIS patients receiving NOAC for at least 24 h and consecutive AIS patients not receiving NOAC into a prospective study. ⋯ In patients receiving rivaroxaban, trough level (68.0 ng/ml, IQR 64.0) was below our predefined upper thresholds that would allow thrombolysis in 4/5 patients. In all patients on apixaban, trough level was above our predefined threshold of 40 ng/ml that precludes thrombolysis (98.2 ng/ml, IQR 84.3). Predefined thresholds of NOAC plasma levels in the decision of thrombolysis in NOAC treated AIS patients might supplement routine coagulation tests and should be validated in a larger study population.
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J. Thromb. Thrombolysis · Feb 2016
ReviewWho, when, and how to reverse non-vitamin K oral anticoagulants.
Non-vitamin K oral anticoagulants (NOACs) have been a major addition to our therapeutic armamentarium. They are at least as effective as warfarin in the thromboprophylaxis of non-valvular atrial fibrillation and management of thromboembolic disease, with a more favorable safety profile. Their predictable pharmacokinetics and pharmacodynamics allow for a fixed oral dosing without the need for anticoagulation monitoring. ⋯ Preclinical studies show promising results and these agents are already in different stages of clinical development. Phase I and II clinical trials demonstrate efficacy in reversing NOACs without major side effects. Until these agents become commercially available, management of patients receiving NOACs who present with major bleeding or require emergent surgery should focus on (a) immediate discontinuation of NOACs, (b) supportive measures or postponing surgery for 12-24 h after the last NOAC dose, and/or
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J. Thromb. Thrombolysis · Feb 2016
ReviewUniversal, class-specific and drug-specific reversal agents for the new oral anticoagulants.
Although there is controversy about the absolute need for a reversal agent for the new direct oral anticoagulants (DOACs), the absence of such an agent is a barrier to more widespread use of these agents. For the management of major life-threatening bleeding with the DOACs, most authorities recommend the use of four factor prothrombin complex concentrates, although the evidence to support their use in terms of improving outcomes is meager. ⋯ Andexanet alfa is a class-specific antidote targeted to reverse the oral direct factor Xa inhibitors as well as the indirect inhibitor, enoxaparin. Ciraparantag is a universal antidote targeted to reverse the direct thrombin and factor Xa inhibitors as well as the indirect inhibitor, enoxaparin.