Management of new oral anticoagulants related life threatening or major bleedings in real life: a brief report

Gastrointestinal Bleeding and Direct Oral Anticoagulants among Patients with Atrial Fibrillation: Risk, Prevention, Management, and Quality of Life

A significant problem for patients undergoing oral anticoagulation therapy is gastrointestinal bleeding (GIB), a problem that has become increasingly urgent following the introduction of direct oral anticoagulants (DOACs). Furthermore, in recent years a greater focus has been placed on the quality of life (QOL) of patients on long-term oral anticoagulant therapy, which necessitates changes in lifestyle, as well as posing an increased risk of bleeding without producing objective symptomatic relief. Here, we examine current evidence linked to GIB associated with oral anticoagulants, with a focus on randomized control trials, meta-analyses, and postmarketing observational studies. Rivaroxaban and dabigatran (especially the 150-mg bis-in-die dose) appeared to be linked to an increased risk of GIB. The risk of GIB was also greater when edoxaban was used, although this was dependent on the dose. Apixaban did not pose a higher risk of GIB in comparison with warfarin. We provided a summary of current knowledge regarding GIB risk factors for individual anticoagulants, prevention strategies that lower the risk of GIB and management of DOAC therapy after a GIB episode.

The impact of prothrombin complex concentrates when treating DOAC-associated bleeding: a review

Background

Bleeding complications are a risk associated with all anticoagulants. Currently, the treatment options for the management of direct oral anticoagulant (DOAC)-associated bleeding are limited. Prothrombin complex concentrates (PCCs) have been proposed as a potential therapeutic option, and evidence regarding their use is increasing.

Review

Many studies supporting PCC have used preclinical models and healthy volunteers; however, more recently, observational studies have further improved insight into current DOAC reversal strategies. Multiple clinical practice guidelines now specifically suggest use of PCCs for this indication. Specific reversal agents for Factor Xa inhibitors may become available in the near future, but data on their efficacy are still emerging.

Conclusions

Ultimately, a multimodal approach may be the optimal strategy to restore haemostasis in patients presenting with DOAC-associated coagulopathy.

Electronic supplementary material

The online version of this article (10.1186/s12245-018-0215-6) contains supplementary material, which is available to authorized users.

Emergency care of patients receiving non-vitamin K antagonist oral anticoagulants

Non-vitamin K antagonist oral anticoagulants (NOACs), which inhibit thrombin (dabigatran) and factor Xa (rivaroxaban, apixaban, edoxaban) have been introduced in several clinical indications. Although NOACs have a favourable benefit-risk profile and can be used without routine laboratory monitoring, they are associated-as any anticoagulant-with a risk of bleeding. In addition, treatment may need to be interrupted in patients who need surgery or other procedures. The objective of this article, developed by a multidisciplinary panel of experts in thrombosis and haemostasis, is to provide an update on the management of NOAC-treated patients who experience a bleeding episode or require an urgent procedure. Recent advances in the development of targeted reversal agents are expected to help streamline the management of NOAC-treated patients in whom rapid reversal of anticoagulation is required.

Reversing the anticoagulation effects of dabigatran

The standard of care for oral anticoagulation therapy has primarily been warfarin, which is limited by its indirect mechanism-of-action, variable kinetics, tolerability, and routine monitoring concerns. The direct-acting oral anticoagulants (DOACs) have predictable pharmacokinetics and pharmacodynamics, and improved safety and efficacy compared to warfarin for the prevention of stroke in patients with nonvalvular atrial fibrillation and prevention or management of venous thromboembolism. Consequential bleeding is a concern with all anticoagulants. Vitamin K is not a rapid reversal agent for warfarin; rather it facilitates synthesis of new vitamin K-dependent clotting factors, which can take longer than 24 h. Other nonspecific agents, including recombinant activated factor VII, three- and four-factor prothrombin complex concentrates (PCC), and activated PCC or Factor Eight Inhibitor Bypassing Activity (FEIBA®), are options based on clinical need. Specific agents to quickly reverse the effects of DOACs have been under development, and idarucizumab, a monoclonal antibody fragment that rapidly binds dabigatran, has been approved for clinical use in cases of dabigatran-related life-threatening bleeding, or if a dabigatran-treated patient needs emergency surgery or an invasive procedure. Idarucizumab specifically and rapidly reverses dabigatran-induced anticoagulation as measured by established coagulation assays. However, this does not guarantee complete hemostasis, especially if a patient has underlying comorbidities such as renal or liver disease, or has experienced recent trauma that requires urgent surgery. In these cases, concomitant supportive therapy and/or administration of concentrated clotting factors may be considered. Emerging data from ongoing trials and clinical experience will further inform providers regarding optimal approaches for anticoagulation reversal.

Gastrointestinal bleeding in patients on novel oral anticoagulants: Risk, prevention and management

Novel oral anticoagulants (NOACs), which include direct thrombin inhibitor (dabigatran) and direct factor Xa inhibitors (rivaroxaban, apixaban and edoxaban), are gaining popularity in the prevention of embolic stroke in non-valvular atrial fibrillation as well as in the prevention and treatment of venous thromboembolism. However, similar to traditional anticoagulants, NOACs have the side effects of bleeding, including gastrointestinal bleeding (GIB). Results from both randomized clinical trials and observations studies suggest that high-dose dabigatran (150 mg b.i.d), rivaroxaban and high-dose edoxaban (60 mg daily) are associated with a higher risk of GIB compared with warfarin. Other risk factors of NOAC-related GIB include concomitant use of ulcerogenic agents, older age, renal impairment, Helicobacter pylori infection and a past history of GIB. Prevention of NOAC-related GIB includes proper patient selection, using a lower dose of certain NOACs and in patients with renal impairment, correction of modifiable risk factors, and prescription of gastroprotective agents. Overt GIB can be managed by withholding NOACs followed by delayed endoscopic treatment. In severe bleeding, additional measures include administration of activated charcoal, use of specific reversal agents such as idarucizumab for dabigatran and andexanent alfa for factor Xa inhibitors, and urgent endoscopic management.

Efficacy of prothrombin complex concentrates for the emergency reversal of dabigatran-induced anticoagulation

Dabigatran is effective in decreasing the risk of ischaemic stroke in patients with atrial fibrillation. However, like all anticoagulants, it is associated with a risk of bleeding. In cases of trauma or emergency surgery, emergency reversal of dabigatran-induced anticoagulation may be required. A specific reversal agent for dabigatran, idarucizumab, has been approved by the US Food and Drug Administration. Alternative reversal agents are available, such as prothrombin complex concentrates (PCCs) and activated PCCs (aPCCs). In this review we evaluate the role of PCCs and aPCCs in the reversal of dabigatran anticoagulation and consider which tests are appropriate for monitoring coagulation in this setting. Pre-clinical studies, small clinical studies and case reports indicate that PCCs and aPCCs may be able to reverse dabigatran-induced anticoagulation in a dose-dependent manner. However, dosing based on coagulation parameters can be difficult because available assays may not provide adequate sensitivity and specificity for measuring anticoagulation induced by dabigatran or the countering effects of PCCs/aPCCs. In addition, PCCs or aPCCs can potentially provoke thromboembolic complications. Despite these limitations and the fact that PCCs and aPCCs are not yet licensed for dabigatran reversal, their use appears to be warranted in patients with life-threatening haemorrhage if idarucizumab is not available.

Four-factor prothrombin complex concentrate reverses apixaban-associated bleeding in a rabbit model of acute hemorrhage

BACKGROUND

Apixaban is a direct factor Xa inhibitor approved for the treatment and prevention of thromboembolic disease. There is a lack of data regarding its reversal in cases of acute bleeding or prior to emergency surgery that needs addressing.

OBJECTIVES

This study assessed whether a four-factor prothrombin complex concentrate (4F-PCC; Beriplex(®) /Kcentra(®) , CSL Behring) can effectively reverse apixaban-associated bleeding in an in vivo rabbit model and evaluated the correlations between in vivo hemostasis and in vitro coagulation parameters.

METHODS

For dose-finding purposes, anesthetized rabbits were treated with a single intravenous dose of apixaban (800-1600 μg kg(-1) ) and, following a standardized kidney incision, volume of blood loss and time to hemostasis were measured. In a subsequent study phase, anesthetized rabbits were treated with apixaban 1200 μg kg(-1) followed by 4F-PCC (6.25-100 IU kg(-1) ), and the effects on the same bleeding parameters were assessed. In parallel, coagulation parameters were monitored.

RESULTS

Dose-dependent increases in time to hemostasis and total blood loss were observed post apixaban administration. Preincision treatment with 4F-PCC resulted in a statistically significant reversal in bleeding time (all doses) and volume (doses ≥ 12.5 IU kg(-1) ). Of the coagulation parameters measured, thrombin generation initiated using the RD reagent (phospholipids only) was the most sensitive to in vivo measures of 4F-PCC's hemostatic efficacy, although some correlations were also observed for prothrombin time and whole blood clotting time.

CONCLUSIONS

In this rabbit model of acute hemorrhage, 4F-PCC showed potential for reversing the bleeding effects of apixaban. Clinical data in apixaban-treated patients are needed to confirm these results.