Is there a role for the laboratory monitoring in the management of specific antidotes of direct oral anticoagulants?

Given the growing number of patients receiving direct oral anticoagulant (DOAC), patients requiring rapid neutralization is also increasing in case of major bleedings or urgent surgery/procedures. Idarucizumab is commercialized as a specific antidote to dabigatran while andexanet alfa has gained the Food and Drug Administration and the European Medicines Agency approval as an oral anti-factor Xa inhibitors antidote. Other antidotes or hemostatic agents are still under preclinical or clinical development, the most advanced being ciraparantag. DOAC plasma levels measurement allows to appropriately select patient for antidote administration and may prevent unnecessary prescription of expensive molecules in some acute clinical settings. However, these tests might be inconclusive after some antidote administration, namely andexanet alfa and ciraparantag. The benefit of laboratory monitoring following DOAC reversal remains unclear. Here, we sought to provide an overview of the key studies evaluating the safety and efficacy of DOAC reversal using the most developed/commercialized specific antidotes, to discuss the potential role of the laboratory monitoring in the management of patients receiving DOAC specific antidotes and to highlight the areas that deserve further investigations in order to establish the exact role of laboratory monitoring in the appropriate management of DOAC specific antidotes.

Idarucizumab for Emergency Reversal of the Anticoagulant Effects of Dabigatran: Final Results of a Japanese Postmarketing Surveillance Study

INTRODUCTION

Idarucizumab, a monoclonal antibody fragment that rapidly reverses the anticoagulant effects of dabigatran, was approved in Japan in September 2016, at which time an all-case, postmarketing surveillance (PMS) study was initiated to collect data on idarucizumab in Japanese patients. Interim results were published previously, and the final results are reported herein.

METHODS

This multicenter, open-label, uncontrolled, non-interventional PMS study was conducted in Japanese patients who received idarucizumab at the approved dose (2 × 2.5 g/50 ml) and had uncontrolled bleeding (group A) or required an emergency procedure (group B). The primary endpoint was the frequency of adverse drug reactions (ADRs). The secondary endpoint was the maximum extent of reversal of the anticoagulant effects of dabigatran, within 4 h of idarucizumab administration, based on activated partial thromboplastin time (aPTT).

RESULTS

The final analysis included 804 patients. ADRs during the idarucizumab treatment and post-treatment periods were reported in 17 of 542 patients (3.1%) in group A and 12 of 240 patients (5.0%) in group B. Thrombotic events were reported in 22 patients (4.1%) in group A and 15 patients (6.3%) in group B, and hypersensitivity occurred in four (0.7%) and five patients (2.1%), respectively. Among 793 patients evaluated for effectiveness, 78 in group A and 26 in group B had aPTT data at baseline (immediately before idarucizumab administration) and within 4 h of idarucizumab administration; in these patients, median maximum percentage reversal within 4 h of idarucizumab administration was 100%.

CONCLUSIONS

The final analysis from the PMS study confirms previous findings suggesting that idarucizumab can safely and effectively reverse the anticoagulant effects of dabigatran in Japanese patients in clinical practice. The results support the continued use of idarucizumab in Japan.

TRIAL REGISTRATION

This study is registered with ClinicalTrials.gov (NCT02946931).

Idarucizumab for dabigatran reversal: A systematic review and meta-analysis of indications and outcomes

BACKGROUND

Idarucizumab has been approved to reverse the anticoagulant effect of dabigatran. However, there is little knowledge of the effectiveness and safety of idarucizumab in daily practice.

AIMS

This systematic review and meta-analysis aims to evaluate the use, effectiveness and outcomes of idarucizumab.

METHODS

A systematic literature search was performed up to September 8th 2022. Original studies including patients prescribed idarucizumab, evaluating prescription indications, prescription appropriateness, haemostatic efficacy and/or the occurrence of adverse events were eligible. Case-reports and studies performed in patients ≤18 years or in healthy volunteers were excluded. Study selection and data extraction were performed by two independent reviewers. Pooled estimates were calculated using the random-effects model, after Freeman-Tukey double-arcsine transformation.

RESULTS

Thirty studies comprising 3602 patients were included. Idarucizumab was prescribed for bleeding (63.1 %, 95%CI 57.0 %-69.0 %), invasive procedures (30.5 %, 95%CI: 24.1 %-37.2 %), to enable thrombolysis (range: 2.0 %-27.3 %), dabigatran intoxication without bleeding (range: 3.6 %-7.0 %) or unspecified reasons (range: 0.4 %-18.8 %). Overall, 2.8 % (95%CI 0.5 %-6.2 %) of prescription indications were reported to be inappropriate upon post-hoc evaluation. Hemostatic effectiveness was achieved in 77.7 % (95%CI 66.7 %-87.2 %) and peri-procedural haemostasis was normal in 98.5 % (95%CI 86.6 %-100 %) of patients. The pooled incidences of all-cause mortality and thromboembolic events at any follow-up duration were 13.6 % (95%CI 9.6 %-17.9 %) and 2.0 % (95%CI 0.8 %-3.4 %), respectively.

CONCLUSION

Idarucizumab was mainly prescribed in the setting of bleeding. The reported hemostatic effectiveness was good, especially perioperatively, and the incidence of thromboembolic events was low. Patients with dabigatran-associated bleeding or requiring an urgent procedure nonetheless face a high mortality risk.

Reversal agents for current and forthcoming direct oral anticoagulants

Over the past 20 years, there has been a shift from vitamin K antagonists to direct oral anticoagulants (DOACs), which include the thrombin inhibitor dabigatran and the factor Xa inhibitors apixaban, edoxaban, and rivaroxaban. Although DOACs are associated with less serious bleeding than vitamin K antagonists, bleeding still occurs with DOACs, particularly in the elderly and in those with comorbidities. Reversal of the anticoagulant effects of the DOACs may be needed in patients with serious bleeding and in those requiring urgent surgery or intervention. Reversal can be effected with specific agents, such as idarucizumab for dabigatran and andexanet alfa for apixaban, edoxaban, and rivaroxaban, or with non-specific agents, such as prothrombin complex concentrates, activated prothrombin complex concentrate, and recombinant activated factor VII. This paper (i) provides an update on when and how to reverse the DOACs, (ii) describes new reversal agents under development, and (iii) provides a strategic framework for the reversal of the factor XI inhibitors currently under investigation in phase three clinical trials.

When and How to Use Reversal Agents for Direct Oral Anticoagulants?

PURPOSE OF REVIEW

Our objective is to describe currently available reversal agents for direct oral anticoagulants (DOACs), their target population, the available clinical practice recommendations and future directions.

RECENT FINDINGS

Specific (idarucizumab for dabigatran and andexanet alfa for direct factor Xa inhibitors) and non-specific (prothrombin complex concentrates) reversal agents are effective in neutralizing the anticoagulant effect of DOACs. New investigational antidotes such as ciraparantag and VMX-C001 offer an alternative to andexanet alfa in reversing the anticoagulant activity of direct oral factor Xa inhibitors, but more clinical data are needed before they could be licensed for use. Specific reversal agents are recommended for use in clinical situations within their licensed indications (i.e.: reversal of DOACs in patients with severe uncontrolled or life-threatening bleeding or in need of emergency surgery or other invasive procedures), while non-specific reversal agents may be used when specific antidotes are not available or indicated.

Standard operating procedure for idarucizumab reversal of dabigatran anticoagulation in ischemic and hemorrhagic stroke

BACKGROUND

Reversal of dabigatran anticoagulation activity using idarucizumab is indicated for individuals suffering from life-threatening or non-controlled bleeding and those in need of urgent operation or invasive intervention. Through idarucizumab application patients with acute ischemic stroke (AIS) may regain eligibility for intravenous thrombolysis (IVT) and patients with intracranial hemorrhage (ICH) may show less hematoma growth, thereby improving functional outcome in both groups. However, evidence is limited, and international guidelines contain heterogenous recommendations substantiating the need for the review of evidence and standard operating procedures (SOPs).

MATERIALS AND METHODS

For our review, we searched PubMed for all published articles using idarucizumab and ischemic stroke/hemorrhagic stroke as keywords. Illustrating two clinical cases, we discuss the current literature and national guidelines.

RESULTS

Our search retrieved 47 articles of which 8 case studies or series made public after 2020/2021, 28 reviews, 1 leading opinion article, 1 editorial and 10 guidelines. Summarizing the available evidence, idarucizumab application in stroke patients taking dabigatran results in decreased mortality rate and improved functional outcomes. Based on two clinical cases from our departments, we provide SOPs on how to deal with eligible patients in a time-efficient way, thereby reducing door-to-needle times in AIS and preventing early deterioration in ICH patients.

CONCLUSION

Reversal of dabigatran with idarucizumab in stroke patients appears easy to manage, safe and beneficial. The SOPs aim to reassure stroke physicians to include dabigatran reversal into their daily clinical routine when dealing with patients presenting with ischemic or hemorrhagic stroke under dabigatran therapy.

A short review of ciraparantag in perspective of the currently available anticoagulant reversal agents

Despite the improved safety-profile of direct oral anticoagulants (DOACs), bleeding complications remain an important side effect of anticoagulant treatment. Although anticoagulant-specific antidotes are available, an universal anticoagulant reversal agent in case of life-threatening bleeding or emergency surgery is not yet available. Ciraparantag, a synthetic small molecule that inactivates heparins and DOAC, is a promising new reversal agent that has been investigated in phase 2 trials. In this short review we provide an overview of the preclinical and clinical evidence of ciraparantag, and compare strengths and weaknesses of ciraparantag and the currently available anticoagulant reversal strategies.

Treatment strategy of dabigatran etexilate following the availability of idarucizumab in Japanese patients with non-valvular atrial fibrillation: J-Dabigatran Surveillance 2

BACKGROUND

Idarucizumab, a dabigatran-specific reversal agent, was launched in Japan in 2016. The J-Dabigatran Surveillance 2 study was designed to assess the characteristics and outcomes of dabigatran-treated patients after the launch of idarucizumab.

METHODS

Patient characteristics and outcomes, including thromboembolic and bleeding events, of dabigatran-naïve patients with non-valvular atrial fibrillation (NVAF) who received dabigatran etexilate [110 mg or 150 mg twice-daily (b.i.d.)] for the prevention of ischemic stroke and systemic embolism were investigated and presented descriptively. Absolute standardized differences (ASD) in baseline characteristics compared with the first J-Dabigatran Surveillance (J-Dabi1; 2011-2013) study were included.

RESULTS

In total, 5660 patients were enrolled and 5436 were analyzed in this study; 3516 and 1898 received 110 mg b.i.d. and 150 mg b.i.d. dabigatran, respectively; 22 received other doses. The overall duration of follow-up (mean ± standard deviation) was 287 ± 179 days. Baseline characteristics, including stroke/bleeding-risk scores, were typical of this patient population. Overall, paroxysmal, persistent, permanent, and symptomatic atrial fibrillation were observed for 53.2%, 27.1%, 13.7%, and 53.9% of patients, respectively (J-Dabi1 ASD: 0.2, 0.0, 0.3, and 0.2, respectively). Catheter ablation was selected in 27.9% of patients (J-Dabi1 ASD: 0.6). Rates of clinical outcomes were low in the study (mostly <2%/year). The incidence rate of major bleeding was 1.1%/year (n = 46) and stroke/transient ischemic attack/systemic embolism was 1.7%/year (n = 71). Twelve (0.2%) patients received idarucizumab, commonly for serious bleeding events, and most recovered.

CONCLUSIONS

Dabigatran continues to be safe and well tolerated in patients with NVAF for stroke and systemic embolism prevention and continues to be prescribed appropriately. Treatment outcomes have not changed since the availability of idarucizumab. Since the J-Dabi1 study, treatment guidelines for anticoagulation use in NVAF have been updated based on emerging clinical evidence, accounting for differences in patient characteristics, and making dabigatran a preference for distinct patient populations.

Idarucizumab reverses dabigatran-induced anticoagulation in treatment of gastric bleeding: A case report

BACKGROUND

The drug instructions for dabigatran recommend adjusting the dosage to 110 mg twice daily for patients with bleeding risk, and performing at least one renal function test per year for patients with moderate renal impairment. However, owing to chronic insidiously worsening renal insufficiency, dabigatran can still accumulate abnormally, necessitating therapy with idarucizumab to reverse the anticoagulation due to severe erosive gastritis with widespread stomach mucosal bleeding.

CASE SUMMARY

A 76-year-old woman with a history of atrial fibrillation who took dabigatran 110 mg twice daily as directed to lessen the chance of stroke, was transported to the hospital with hematemesis and melena. Laboratory findings revealed severe life-threatening, blood-loss-induced anemia with a hemoglobin (Hb) level of 41.0 g/L and marked coagulation abnormalities with thrombin time (TT) > 180 s, most likely caused by dabigatran-induced metabolic disorder. Aggressive acid suppressive, hemostatic, and blood transfusion therapy resulted in the misconception that the bleeding was controlled, with subsequent rebleeding. Idarucizumab was administered in a timely manner to counteract dabigatran's anticoagulant impact, and 12 h later, TT was determined to be 17.4 s, which was within the normal range. Finally, the patient had no active bleeding signs and laboratory findings showed an Hb level of 104 g/L and TT of 17.7 s.

CONCLUSION

Renal function, coagulation function, and dabigatran concentration should be regularly monitored in older patients. Proton pump inhibitor and dabigatran coadministration is still controversial in preventing upper gastrointestinal tract bleeding.

Anticoagulant Reversal in Gastrointestinal Bleeding: Review of Treatment Guidelines

BACKGROUND

Patients receiving anticoagulant therapies, such as vitamin K antagonists (VKAs) or direct oral anticoagulants (DOACs), commonly experience gastrointestinal (GI) bleeding as a complication and may require anticoagulant reversal prior to endoscopic treatment. Anticoagulant reversal agents include prothrombin complex concentrates (PCCs; including 3 or 4 coagulation factors), plasma, vitamin K, and target-specific DOAC reversal agents (e.g., idarucizumab and andexanet alfa).

AIM

To review current US, as well as international, guidelines for anticoagulant reversal agents in patients on VKAs or DOACs presenting with GI bleeding prior to endoscopy, guideline-based management of coagulation defects, timing of endoscopy, and recommendations for resumption of anticoagulant therapy following hemostasis. Supporting clinical data were also reviewed.

METHODS

This is a narrative review, based on PubMed and Internet searches reporting GI guidelines and supporting clinical data.

RESULTS

GI-specific guidelines state that use of reversal agents should be considered in patients with life-threatening GI bleeding. For VKA patients presenting with an international normalized ratio > 2.5, guidelines recommend PCCs (specifically 4F-PCC), as they may exhibit greater efficacy/safety compared with fresh frozen plasma in reversal of VKA-associated GI bleeding. For DOAC patients, most guidelines recommend targeted specific reversal agents in the setting of GI bleeding; however, PCCs (primarily 4F-PCC) are often listed as another option. Resumption of anticoagulant therapy following cessation of GI bleeding is also recommended to reduce risks of future thromboembolic complications.

CONCLUSIONS

The utility of anticoagulant reversal agents in GI bleeding is recognized in guidelines; however, such agents should be reserved for use in truly life-threatening scenarios.

Impact of Idarucizumab and Andexanet Alfa on DOAC Plasma Concentration and ClotPro® Clotting Time: An Ex Vivo Spiking Study in A Cohort of Trauma Patients

Specific antagonists have been developed for the reversal of direct oral anticoagulants (DOAC). We investigated the impact of these reversal agents on the plasma concentration and visco-elastic test results of dabigatran and factor Xa inhibitors. After baseline measurements of dabigatran, the plasma concentration, and the visco-elastic ClotPro^® ecarin clotting time (ECA-CT), we added the reversal agent Idarucizumab in vitro and these two analyses were repeated. Likewise, the baseline plasma concentration of apixaban, edoxaban, and rivaroxaban as well as ClotPro^® Russell’s viper venom test clotting time (RVV-CT) were measured and reanalyzed following Andexanet alfa spiking. We analyzed fifty blood samples from 37 patients and 10 healthy volunteers. Idarucizumab decreased the measured dabigatran plasma concentration from 323.9 ± 185.4 ng/mL to 5.9 ± 2.3 ng/mL and ECA-CT from 706.2 ± 344.6 s to 70.6 ± 20.2 s, (all, p < 0.001). Andexanet alfa decreased the apixaban concentration from 165.1 ± 65.5 ng/mL to 9.8 ± 8.1 ng/mL, edoxaban from 152.4 ± 79.0 ng/mL to 36.4 ± 19.2 ng/mL, and rivaroxaban from 153.2 ± 111.8 ng/mL to 18.1 ± 9.1 ng/mL (all p < 0.001). Andexanet alfa shortened the RVV-CT of patients with apixaban from 239.2 ± 71.7 s to 151.1 ± 30.2 s, edoxaban from 288.2 ± 65.0 s to 122.7 ± 37.1 s, and rivaroxaban from 225.9 ± 49.3 s to 103.7 ± 12.1 s (all p < 0.001). In vitro spiking of dabigatran-containing blood with Idarucizumab substantially reduced the plasma concentration and ecarin-test clotting time. Andexanet alfa lowered the concentration of the investigated factor Xa-inhibitors but did not normalize the RVV-CT. In healthy volunteers’ blood, Idarucizumab spiking had no impact on ECA-CT. Andexanet alfa spiking of non-anticoagulated blood prolonged RVV-CT (p = 0.001), potentially as a consequence of a competitive antagonism with human factor Xa.

Clinical protocols for oral anticoagulant reversal during high risk of bleeding for emergency surgical and nonsurgical settings: a narrative review

Background and objectives

Oral anticoagulants prevent thromboembolic events but expose patients to a significant risk of bleeding due to the treatment itself, after trauma, or during surgery. Any physician working in the emergency department or involved in the perioperative care of a patient should be aware of the best reversal approach according to the type of drug and the patient’s clinical condition. This paper presents a concise review and proposes clinical protocols for the reversal of oral anticoagulants in emergency settings, such as bleeding or surgery.

Contents

The authors searched for relevant studies in PubMed, LILACS, and the Cochrane Library database and identified 82 articles published up to September 2020 to generate a review and algorithms as clinical protocols for practical use. Hemodynamic status and the implementation of general supportive measures should be the first approach under emergency conditions. The drug type, dose, time of last intake, and laboratory evaluations of anticoagulant activity and renal function provide an estimation of drug clearance and should be taken into consideration. The reversal agents for vitamin K antagonists are 4-factor prothrombin complex concentrate and vitamin K, followed by fresh frozen plasma as a second-line treatment. Direct oral anticoagulants have specific reversal agents, such as andexanet alfa and idarucizumab, but are not widely available. Another possibility in this situation, but with less evidence, is prothrombin complex concentrates.

Conclusion

The present algorithms propose a tool to help healthcare providers in the best decision making for patients under emergency conditions.

Difficult reversal of dabigatran with idarucizumab in a multiple-trauma patient: A question of dose?

Dabigatran is an oral anticoagulant directly acting as thrombin inhibitor. The monoclonal antibody idarucizumab was developed to reverse its anticoagulatory effects after application of a standardized dose. Following administration, dabigatran plasma level rebounds have been reported but its consequences are not fully understood. We report a case of a multiple-trauma patient under dabigatran treatment suffering from secondary bleeding relapse after initially successful reversal with idarucizumab. Stabilisation of the patient's coagulopathy and subsequent bleeding was not achieved until application of an additional dose of idarucizumab. We conclude that patients treated with dabigatran and presenting with active bleeding require close attention to its reversal with standard doses of idarucizumab. Screening for thrombin time was shown beneficial in early detection of dabigatran rebound in this case.

Real-world experience with reversal of dabigatran by idarucizumab

AIMS

Idarucizumab reverses the anticoagulant effect of dabigatran. We aimed to investigate real-world experience with idarucizumab and associated clinical outcomes.

METHODS

We conducted a retrospective observational case series on dabigatran users treated with idarucizumab. Using electronic patient records, we identified patients from December 2015 (market introduction) to 31 December 2019 from the Central Denmark Region, covering approximately 1.3 million inhabitants. Treatment indications included need of acute surgery, major bleeding, dabigatran intoxication and need of thrombolysis. Outcomes were defined according to treatment indication, and adverse events were defined as bleeding, thrombosis or death within 30 days of infusion.

RESULTS

A total of 46 dabigatran users were treated with idarucizumab. All patients except one received dabigatran due to atrial fibrillation. Indications for idarucizumab use were need of acute surgery in 22 (48%), severe bleeding in 20 (43%), dabigatran intoxication in three (7%), and prior to thrombolysis in acute stroke in one (2%) patient. There were no reports of excessive bleeding during surgery in patients reversed just prior to surgery. For patients presenting with severe bleeding, all but one achieved effective haemostasis. Among all patients receiving idarucizumab, six (13%) experienced bleeding within 30 days after infusion. None experienced thromboembolic complications. At 30 days follow-up, 38 (83%) patients were alive of whom 35 (92%) had restarted anticoagulant treatment.

CONCLUSION

This study of real-world application of idarucizumab demonstrated effectiveness in terms of surgery performed without excessive bleeding and cessation of severe bleeding in dabigatran-treated patients. Safety appeared high as no patients experienced thromboembolic complications within 30 days.

Direct oral anticoagulants: a review on the current role and scope of reversal agents

New guideline recommendations prefer direct oral anticoagulants (DOACs) over warfarin in DOAC-eligible patients with atrial fibrillation and patients with venous thromboembolism. As expected with all antithrombotic agents, there is an associated increased risk of bleeding complications in patients receiving DOACs that can be attributed to the DOAC itself, or other issues such as acute trauma, invasive procedures, or underlying comorbidities. For the majority of severe bleeding events, the widespread approach is to withdraw the DOAC, then provide supportive measures and "watchful waiting" with the expectation that the bleeding event will resolve with time. However, urgent reversal of anticoagulation may be advantageous in patients with serious or life-threatening bleeding or in those requiring urgent surgery or procedures. Until recently, the lack of specific reversal agents, has affected the uptake of these agents in clinical practice despite a safer profile compared to warfarin in clinical trials. In cases of life-threatening or uncontrolled bleeding or when patients require emergency surgery or urgent procedures, idarucizumab has been recently approved for reversal of anticoagulation in dabigatran-treated patients and andexanet alfa for factor Xa inhibitor-treated treated patients. The current review summarizes the current clinical evidence and scope of these agents with the potential impact on DOAC use in clinical practice.

Idarucizumab Reverses Dabigatran Anticoagulant Activity in Healthy Chinese Volunteers: A Pharmacokinetics, Pharmacodynamics, and Safety Study

INTRODUCTION

Idarucizumab is a humanized monoclonal antibody fragment that specifically binds to dabigatran with high affinity and reverses its anticoagulant effect. This study investigated the pharmacokinetics (PK) and pharmacodynamics (PD) of idarucizumab in healthy Chinese subjects at steady state of dabigatran and explored the effect of idarucizumab on PK and PD of dabigatran.

METHODS

Twelve subjects received dabigatran etexilate treatment alone (220 mg twice daily, b.i.d., oral). After a washout period, the 12 subjects again received dabigatran etexilate (220 mg b.i.d., oral) and idarucizumab (2.5 + 2.5 g, intravenous) 2 h after the last administration of dabigatran etexilate.

RESULTS

The geometric mean (gMean) values of area under the plasma concentration-time curve (AUC_0-∞) and maximum concentration (C_max) were 44,200 nmol h/L and 30,900 nmol/L, respectively. An amount of 35.3 μmol of idarucizumab, corresponding to 33.8% of the total dose, was excreted by urine over 72 h. The area under the effect (AUEC_above,2-12) in the presence and absence of idarucizumab was close to zero for all coagulation parameters, diluted thrombin time (dTT), ecarin clotting time (ECT), activated partial thromboplastin time (aPTT), and thrombin time (TT), which indicated the reversal of dabigatran anticoagulation by idarucizumab. There were no serious adverse events reported in this study. No subject tested positive for anti-idarucizumab antibodies.

CONCLUSION

Idarucizumab was well tolerated and no subject tested positive for anti-idarucizumab antibodies in this study. PK and PD of idarucizumab in healthy Chinese subjects at a steady state of dabigatran were comparable with those in Japanese and Caucasian subjects.

CLINICAL REGISTRATION

ClinicalTrials.gov Identifier No. NCT03086356.

[TEG-guided treatment of a dabigatran overdose in a patient with acute kidney failure]

This article presents the case of a multimorbid male patient with an accidental dabigatran overdose caused by kidney failure in the context of an acute intestinal disorder. After effective initial antagonizing of the dabigatran effect using idarucizumab a dabigatran rebound was detected caused by a single hemodialysis leading to a severe intrapulmonary hemorrhage. As dabigatran plasma level testing was not available and conventional coagulation analysis was out of interpretable range due to the impact of dabigatran, continuous thrombelastography (TEG) was used to detect the effect of dabigatran and monitor the treatment results. The most significant parameter used in the kaolin activated clotting time was the R‑time parameter, which was massively prolonged by the interrupted coagulation cascade.

Revascularization outcomes following acute ischemic stroke in patients taking direct oral anticoagulants: a single hospital cohort study

Successful revascularization therapy is of paramount importance in patients suffering acute ischemic stroke (AIS). However, there is currently only limited evidence on revascularization outcomes for patients suffering AIS while treated with direct oral anticoagulants (DOACs). The aim of our study was to determine the efficacy and safety of intravenous thrombolysis (IVT) and mechanical reperfusion (MeR) in AIS patients taking DOACs, and compare them to randomized clinical trials (RCTs), which included patients without DOAC treatment. In an observational cohort study, we analyzed clinical and radiological outcomes following AIS for all consecutive patients on DOAC therapy treated by IVT or MeR, between 2013 and 2019, at the University Medical Center Ljubljana. Patients in the IVT group were on dabigatran treatment and have received idarucizumab as a reversal agent prior to IVT. Patients in the MeR group had a large vessel occlusion. The primary outcome of the study was efficiency, defined as significant improvement after recanalization (National Institutes of Health Stroke Scale (NIHSS) score improvement of ≥8 points after 24 h and modified Rankin Scale (mRS) ≤2 after 3 months) and safety, defined as occurrence of symptomatic intracerebral hemorrhage (SICH) and mortality. Fifty-one DOAC-treated patients with AIS were included. Nineteen dabigatran-treated patients received IVT after reversal by idarucizumab. Thirty-two patients with a large vessel occlusion (12 on dabigatran, 12 on rivaroxaban, and 8 on apixaban) received MeR. Median NIHSS at admission was 9 in the IVT group and 17 in the MeR group. A significant clinical improvement, 24 h after revascularization (median improvement of NIHSS ≥8), occurred in 84% of patients treated with IVT and 25% of patients treated with MeR. A favorable functional outcome after 3 months (modified Rankin Scale (mRS) ≤2) occurred in 84 % of patients treated with IVT and 44% of patients treated with MeR. SICH occurred in one patient (5%) in the IVT group, and in two patients (6%) in the MeR group. In summary, in our observational study of DOAC-treated AIS patients, the level of IVT efficiency was substantially better than in the RCTs. At the same time, the results of MeR treatment were on the same level as in non-DOAC AIS patients included in the RCTs. The observed safety of IVT and MeR treatment was similar to the RCTs. We propose that thrombi in patients on dabigatran may have increased susceptibility to IVT, thereby allowing for better clinical results.

Incidence Rates of Bleeding and Emergency Surgery Due to Trauma or Fracture Among Japanese Patients with Non-valvular Atrial Fibrillation Receiving Oral Anticoagulation Therapy

Introduction

In patients with nonvalvular atrial fibrillation (NVAF) receiving oral anticoagulants (OACs), reversal of coagulopathy can be achieved with specific reversal drugs such as idarucizumab, which is indicated for use in patients treated with dabigatran for cases of life-threatening or uncontrolled bleeding or during emergency procedures that may cause serious bleeding. This study examined the incidence rate (IR) of emergency surgeries and major bleeding episodes associated with fractures and trauma in Japanese patients with NVAF receiving OACs.

Methods

This retrospective, non-interventional analysis of health insurance claims was conducted using data from 62,888 OAC-naive adult patients with NVAF who initiated dabigatran, warfarin, apixaban, rivaroxaban, or edoxaban between March 2011 and June 2016. The primary endpoint was overall IR of emergency surgery or major bleeding due to fracture or trauma.

Results

Overall IR of emergency surgery or major bleeding due to fracture or trauma considering outcomes until OAC discontinuation was 0.489 per 100 patient-years (PY) (95% confidence interval [CI] 0.406–0.572). Considering first OAC exposure only, the IR was 0.483 per 100 PY (95% CI 0.394–0.573). Emergency surgery/major bleeding events due to fracture or trauma was highest in those aged ≥ 75 years (0.611 per 100 PY [95% CI 0.481–0.741]).

Conclusions

Fewer than one in 200 patients per year with NVAF receiving OACs experience emergency surgeries and major bleeding episodes associated with fractures and trauma; however, the IR of these events is markedly higher in patients of advanced age.

Trial registration

ClinicalTrials.gov 207, NCT03254147.

Patients with an abnormal heart rhythm (nonvalvular atrial fibrillation [NVAF]) have a higher risk of blood clots and stroke (which is when the blood supply to part of the brain is blocked). To reduce these risks, patients can take anticoagulants that slow or prevent the formation of blood clots. However, if the patient needs major emergency surgery or has a severe injury, the anticoagulants can increase their risk of bleeding, which can sometimes be life-threatening. There are drugs (e.g., idarucizumab) that can be used to reverse the effects of anticoagulants in this type of emergency. What we don’t know is how many NVAF patients in Japan who are on anticoagulants have emergency surgeries or major bleeding after an injury, and therefore may require a reversal drug. The authors looked at Japanese health insurance claim data from 62,888 adult patients with NVAF who started taking an anticoagulant. They found that, annually, approximately 0.5% of the patients had emergency surgery or a major bleed associated with a fracture or injury. In very elderly patients (aged at least 75 years), the annual percentage was approximately 0.6%, which was almost double the annual percentage in patients aged less than 65 years. The authors concluded that, even though the number of people requiring a reversal agent are quite small, it is important to have an effective reversal agent for patients on anticoagulants, particularly older patients.

Left atrial appendage thrombus on full-dose dabigatran treatment: a case report

Background

Dabigatran is a direct competitive thrombin inhibitor approved for stroke prevention in non-valvular atrial fibrillation. At full-dose, dabigatran showed similar rates of bleedings and higher efficacy compared to warfarin.

Case summary

We report a case of acute ischaemic stroke in a patient treated with dabigatran 150 mg b.i.d. for atrial fibrillation. After an off-label treatment with idarucizumab, a humanized monoclonal antibody approved for dabigatran reversal, we performed a successful intravenous thrombolysis (IVT). Transoesophageal echocardiography showed a left atrial appendage (LAA) thrombus, despite full-dose dabigatran and an adequate therapy adherence.

Discussion

There are few cases of LAA thrombus during dabigatran treatment reported in literature till date. We analyse the possible pathogenetic mechanisms involved in dabigatran failure, including drug interactions and unexpected genetic variations interfering with dabigatran serum levels suggesting periodical assessment of direct Oral Anticoagulant levels. Furthermore, we confirm initial reports of safety and efficacy of intravenous thrombolysis after idarucizumab, in case of dabigatran failure.

Idarucizumab for Emergency Reversal of Anticoagulant Effects of Dabigatran: Interim Results of a Japanese Post-Marketing Surveillance Study

Introduction

Idarucizumab, a monoclonal antibody fragment, was developed to reverse the anticoagulant effect of dabigatran, and it was approved in Japan in September 2016. An all-case post-marketing surveillance is ongoing to collect data in Japanese patients treated with idarucizumab who had serious bleeding (Group A) or required an urgent procedure (Group B).

Methods

The primary endpoint was the incidence of adverse drug reactions (ADRs). The secondary endpoint was the maximum extent of reversal of the anticoagulant effect of dabigatran based on activated partial thromboplastin time (aPTT) within 4 h after idarucizumab administration.

Results

This interim analysis included 262 patients who received idarucizumab. Eighteen patients (6.9%) experienced ADRs within 4 weeks. The reversal effect of idarucizumab based on aPTT within 4 h after idarucizumab administration was assessed in 30 patients and the median maximum percentage reversal was 100%. In Group A, the median time to bleeding cessation in patients without intracranial bleeding was 3.3 h. In Group B, normal intraoperative hemostasis was reported in 63 patients (72.4%).

Conclusions

The results of this interim analysis suggest that idarucizumab is safe and effective for the reversal of dabigatran in Japanese patients in a real-world setting, and support the continued use of idarucizumab.

Trial Registration

ClinicalTrials.gov identifier, NCT02946931.

Antagonizing dabigatran by idarucizumab in cases of ischemic stroke or intracranial hemorrhage in Germany-Updated series of 120 cases

BACKGROUND

Idarucizumab is a monoclonal antibody fragment with high affinity for dabigatran reversing its anticoagulant effects within minutes. Thereby, patients with acute ischemic stroke who are on dabigatran treatment may become eligible for thrombolysis with recombinant tissue-type plasminogen activator (rt-PA). In patients on dabigatran with intracerebral hemorrhage idarucizumab could prevent lesion growth.

AIMS

To provide insights into the clinical use of idarucizumab in patients under effective dabigatran anticoagulation presenting with signs of acute ischemic stroke or intracranial hemorrhage.

METHODS

Retrospective data collected from German neurological/neurosurgical departments administering idarucizumab following product launch from January 2016 to August 2018 were used.

RESULTS

One-hundred and twenty stroke patients received idarucizumab in 61 stroke centers. Eighty patients treated with dabigatran presented with ischemic stroke and 40 patients suffered intracranial bleeding (intracerebral hemorrhage (ICH) in n = 27). In patients receiving intravenous thrombolysis with rt-PA following idarucizumab, 78% showed a median improvement of 7 points in National Institutes of Health Stroke Scale. No bleeding complications were reported. Hematoma growth was observed in 3 out of 27 patients with ICH. Outcome was favorable with a median National Institutes of Health Stroke Scale improvement of 4 points and modified Rankin score 0-3 in 61%. Six out of 40 individuals (15%) with intracranial bleeding died during hospital stay.

CONCLUSION

Administration of rt-PA after reversal of dabigatran activity with idarucizumab in case of acute ischemic stroke seems feasible, effective, and safe. In dabigatran-associated intracranial hemorrhage, idarucizumab appears to prevent hematoma growth and to improve outcome.

Reversal agents for oral anticoagulant-associated major or life-threatening bleeding

Oral anticoagulants (OA) are effective drugs for treating and preventing the formation of blood clots in patients with atrial fibrillation, mechanical heart valves and venous thromboembolism but their therapeutic effect is always counterbalanced by an increased risk of bleeding. Direct oral anticoagulants (DOACs) have brought advantages in the management of many patients, with evidence of a lower risk of intracranial bleeding in comparison to vitamin K antagonists (VKAs). However, due to the increased number of anticoagulated patients worldwide, major and life threatening OA-related bleeding is also increasing, and effective reversal strategies are needed. We reviewed the reversal strategies for both VKAs and DOACs in the light of the latest evidence and recent guidelines, taking into account non-specific methods with fresh frozen plasma (FFP), prothrombin complex concentrate (PCC) or four factor PCC, as well as specific reversal antidotes that are already approved or in approval phase. Most published studies on OA reversal have drawbacks, such as lacking a control arm or data on clinically relevant outcomes, and current guidelines' recommendations are mainly based on panellists' judgment. There is an urgent need for well-designed studies in this field. In the meanwhile, to improve the correct use of available resources and patients' outcomes, we suggest a seven-element bundle for an optimal management of OA-associated major bleeding, including the implementation of fast turnaround time for laboratory tests in emergency, i.e. INR and DOAC plasma levels, and to build up a 'bleeding team' that includes experts of hemostasis, lab, trauma, emergency medicine, endoscopy, radiology, and surgery in every hospital.

Idarucizumab in major trauma patients: a single centre real life experience

INTRODUCTION

Trauma care providers are facing an increasing number of elderly patients on direct oral anticoagulants prior to injury. For dabigatran etexilate (DAB), the specific antagonist idarucizumab (IDA) has been approved since 2015 as a reversal agent. However, only limited data regarding the use of IDA in trauma patients are available.

METHODS

We performed a retrospective analysis of trauma patients under DAB for whom IDA administration was deemed necessary to reverse DAB's antithrombotic effect.

RESULTS

A total of 15 (9 male) patients were treated with IDA during the study period. The mean age was 81 ± 10 years. Intracranial haemorrhage (n = 7) and long bone fractures (n = 5) were the most common types of injury. Three patients were diagnosed as polytrauma. In all but one patient, atrial fibrillation was the indication for DAB intake. The median dose of IDA was 2.5 g (IQR 2.5-5). IDA administration decreased DAB plasma levels from 112.4 (IQR 73.4-123.4) to 5 (IQR 4-12) ng/mL (p = 0.031), thrombin time from 114.8 ± 48.3 to 16.2 ± 0.5 s (p < 0.0001) and activated partial thromboplastin time form 45.4 ± 11.3 to 34.2 ± 7.0 s (p = 0.0025). No thromboembolic events or side effects attributed to IDA were observed. All patients survived until hospital discharge.

CONCLUSIONS

In trauma patients under DAB prior to injury, IDA decreased DAB plasma levels and normalized coagulation parameters. IDA appears to be safe, and no serious side effects were observed in this small cohort of patients.

Idarucizumab administration in emergency situations: the Munich Registry of Reversal of Pradaxa® in clinical routine (MR REPAIR)

OBJECTIVES

To evaluate daily life management and functional outcome of Idarucizumab administration in case of emergency situations in patients with Dabigatran treatment.

DESIGN

Multicenter observational registry study.

SETTING

All hospitals with full neurological departments (n = 6) in Munich, Germany INCLUDED PATIENTS: All patients treated with Idarucizumab from 01/2016 to 03/2019.

ANALYZED DATA

Indication and application of Idarucizumab, demographics and clinical parameters, and further interventions and treatments; clinical outcome was assessed with the modified Rankin scale (mRS) at 3 months after Idarucizumab administration RESULTS: Idarucizumab was administered to 32 patients for severe bleeding complications and ischemic strokes, more precisely for the following specific indications: intracranial bleeding (17 patients, 53%), ischemic stroke (8 patients, 25%), gastrointestinal bleeding (3 patients, 9%), femoral fracture, aortic dissection, and abdominal trauma and ileus (1 patient each, 3%). Additional coagulation management was performed in 7 patients (22%). Nine patients (28%) underwent emergency surgery. Seven patients (22%) received Idarucizumab before intravenous thrombolysis due to ischemic stroke and 4 of these 7 patients (13%) received mechanical thrombectomy in addition. Indication was mainly based on the history of Dabigatran intake and was irrespective of laboratory testing. At follow-up, 25% of the investigated patients had a mRS 0-2, while 25% had an unfavorable outcome (mRS 4-5). Mortality was 31%.

CONCLUSION

In our study, we have shown that the administration of Idarucizumab is a rare intervention and restricted to patients with severe bleeding complications or ischemic stroke. The clinical outcome of patients who received Idarucizumab in emergency situations was poor.

Reversal agents for direct oral anticoagulants: considerations for hospital physicians and intensivists

Direct oral anticoagulants (DOACs) include dabigatran etexilate, a direct thrombin inhibitor, and specific inhibitors of activated coagulation factor X (FXa; e.g. apixaban, betrixaban, edoxaban, rivaroxaban). DOACs are associated with lower rates of major and fatal bleeding events compared with warfarin. Clinicians may need to achieve rapid reversal of anticoagulation effects of the DOACs in an emergency setting. Idarucizumab and andexanet alfa, which reverse the anticoagulant effects of dabigatran and FXa inhibitors, respectively, are DOAC reversal agents available in the US. Other reversal agents (e.g. ciraparantag for heparins, DOACs) are in development. Alternative nonspecific agents (e.g. fresh frozen plasma, prothrombin complex concentrate) are available. Nonspecific prohemostatic agents can counteract the anticoagulant action of DOACs in emergency situations, when specific reversal agents are unavailable. However, specific reversal agents are efficacious and safe and should be preferred when available. In this review, we discuss practical issues in the initiation of DOAC therapy, situations where reversal may be needed, coagulation assays, reversal agents, and post-reversal complications in the context of published evidence and guidelines.

Use of idarucizumab for dabigatran reversal in cardiac tamponade during atrial fibrillation ablation: A case report

It is known that the efficacy of catheter ablation for atrial fibrillation (AF) is high, but cardiac tamponade may occur in 1–2% cases. Even in such cases, fatal condition can be avoided by appropriate drainage, but reversal of anticoagulation therapy might also be necessary. Here, we report a case of use of idarucizumab for cardiac tamponade during AF ablation. Although the drainage with pericardial centesis should be selected, we could not perform because echo free space was too thin at least at the precordial or apical side of the ventricle. Fortunately, dabigatran reversal by idarucizumab suppressed cardiac tamponade progress and the patient recovered without undergoing any invasive procedures. The pericardial drainage must be the principal therapy for cardiac tamponade, but reversal of anticoagulant might be helpful for patients’ recovery. It might be thought that dabigatran, the only direct oral anticoagulant with a specific reversal agent, should be the safest choice in case of risk for bleeding complications such as AF ablation.

<Learning objective: Cardiac tamponade is one of the complications of catheter ablation for atrial fibrillation (AF). In such cases, fatal condition can be avoided by appropriate drainage, but reversal of anticoagulation therapy might be necessary. Drainage with pericardial centesis was not selected because echo free space was too thin. Dabigatran reversal by idarucizumab suppressed cardiac tamponade progress. It was thought that dabigatran would be the safest choice in case of bleeding complications during AF ablation.>

Idarucizumab to revert the anticoagulant effect of dabigatran in traumatic acute subdural haematoma: a case report of first use in Latin America

BACKGROUND 

Direct oral anticoagulants (DOAC) are an attractive alternative over vitamin K antagonists. They have several advantages in primary and secondary prevention of thromboembolisms due to atrial fibrillation, as well as in prevention and treatment of thromboembolic venous disease. They have fast onset action, do not need laboratory controls in patients with normal renal function, and they have practically no interference with the patient's diet or medications. The strongest objection to their use was the lack of reversal agents that could be used in case of life-threatening haemorrhage or the need for emergency surgery. Dabigatran was the first DOAC to have its own specific reversal agent: idarucizumab, a monoclonal antibody.

CASE SUMMARY 

We report here the case of a patient undergoing treatment with dabigatran that suffered an expansive subdural haematoma secondary to a cranial injury. The condition was life-threatening and required emergency surgery. Anticoagulation was successfully reversed with idarucizumab.

DISCUSSION 

Emergency surgery in patients in treatment with DOAC is associated with an increased risk of bleeding. With the use of a specific antidote to block the action of the anticoagulant, as in the case of idarucizumab with dabigatran, the risk of complications during and after emergency surgery is reduced. This is the first case report with which the successful use of idarucizumab in Latin America is documented.

A review of oral anticoagulants, old and new, in major bleeding and the need for urgent surgery

Oral anticoagulants, old and new, are effective therapies for prevention and treatment of venous thromboembolism and reduction of stroke risk in patients with atrial fibrillation. However, blocking elements of the clotting cascade carries an inherent risk of bleeding. Also, anticoagulated patients sometimes require urgent surgery or invasive procedures. This has led to the emergence of a body of scientific literature on the reversal of anticoagulation in these two settings. Traditionally, vitamin K antagonists (VKAs), which indirectly inactivate clotting factors II, VII, IX and X (and natural anticoagulant proteins C and S), had been the mainstay of oral anticoagulation for half a century. Only a few years ago, the US Food and Drug Administration (FDA) approved a specific VKA reversal agent, 4-Factor Prothrombin Complex Concentrate (4F-PCC). The last decade has seen the rise of non-Vitamin K oral anticoagulants (NOACs), which target specific factors, i.e. Factors IIa and Xa. Investigators have rapidly developed reversal agents for these agents as well, idarucizumab for the Factor IIa inhibitor dabigatran (Pradaxa) and andexanet alfa for the entire class of Factor Xa inhibitors (FXaIs), currently four drugs: rivaroxaban (Xarelto), apixaban (Eliquis), edoxaban (Savaysa) and betrixaban (Bevyxxa). Clinicians still use off-label PCC for reversing FXaIs in some settings, and a universal reversal agent, ciraparantag, remains in development. This review summarizes the safety and efficacy of these reversal agents in the setting of anticoagulant-associated major bleeding and the need for urgent surgery.

Diagnostic and therapeutic approach in adult patients with traumatic brain injury receiving oral anticoagulant therapy: an Austrian interdisciplinary consensus statement

There is a high degree of uncertainty regarding optimum care of patients with potential or known intake of oral anticoagulants and traumatic brain injury (TBI). Anticoagulation therapy aggravates the risk of intracerebral hemorrhage but, on the other hand, patients take anticoagulants because of an underlying prothrombotic risk, and this could be increased following trauma. Treatment decisions must be taken with due consideration of both these risks. An interdisciplinary group of Austrian experts was convened to develop recommendations for best clinical practice. The aim was to provide pragmatic, clear, and easy-to-follow clinical guidance for coagulation management in adult patients with TBI and potential or known intake of platelet inhibitors, vitamin K antagonists, or non-vitamin K antagonist oral anticoagulants. Diagnosis, coagulation testing, and reversal of anticoagulation were considered as key steps upon presentation. Post-trauma management (prophylaxis for thromboembolism and resumption of long-term anticoagulation therapy) was also explored. The lack of robust evidence on which to base treatment recommendations highlights the need for randomized controlled trials in this setting.

Reversal of dabigatran using idarucizumab: single center experience in four acute stroke patients

Dabigatran is a direct thrombin inhibitor and a non-vitamin-K-antagonizing oral anticoagulant, approved for the prevention of stroke and systemic embolization in atrial fibrillation. Idarucizumab is a humanized monoclonal antibody that was recently approved for antagonizing the anticoagulant effects of dabigatran. Here, we report the use of idarucizumab in four acute stroke patients treated with dabigatran in order to enable intravenous thrombolysis in three patients and emergent trepanation in one patient with space occupying subdural hematoma. Since experience on the optimal management of acute stroke patients under medication with dabigatran and on the use of idarucizumab is currently limited, we propose an approach for laboratory testing and fast administration of intravenous thrombolysis and neurosurgery based on our experience.

Acute reversal of dabigatran with Idarucizumab for intravenous thrombolysis as acute stroke treatment

Intravenous thrombolysis with recombinant tissue plasminogen activator (rt-PA) for acute ischemic stroke (AIS) is contraindicated in patient taking either Factor Xa inhibitors or direct thrombin inhibitors. Idarucizumab completely reverses the biologic effect of dabigatran within minutes. Intravenous rt-PA treatment results in a significant benefit in functional outcome when administered 3-4.5 h after stroke onset or last seen normal time. There is little reported data and no large-scale studies of the reversal of dabigatran with Idarucizumab for the purpose of treating AIS with IV rt-PA. We describe the case of a 73 year old male with AIS and active dabigatran use. Idarucizumab was administered per an approved medical center protocol and the patient was subsequently treated with IV rt-PA. The patient had a severe stroke with no other contraindications to IV rt-PA other than dabigatran use. The patient was administered Idarucizumab and IV rt-PA was given. Within 24 h of treatment, the patient had minimal stroke deficits. Imaging revealed a right middle cerebral artery patchy infarct. The patient was restarted on dabigatran therapy for his atrial fibrillation and was discharged to a skilled nursing facility for rehabilitation. The patient did not experience any symptomatic or asymptomatic intracranial hemorrhage after treatment or through day 90. Though no randomized evidence exists for the risk of IV rt-PA after dabigatran reversal with Idarucizumab, the case experiences are mounting. This case of successful stroke treatment after reversal adds to the anecdotal literature and supports the study of dabigatran reversal with Idarucizumab for thrombolysis in AIS.

Idarucizumab for a traumatic head injury patient taking dabigatran

Background

Dabigatran is one of the four drugs currently used as a direct oral anticoagulant in Japan. Idarucizumab, which specifically targets dabigatran, was recently approved in Japan. We present a case of intracranial hemorrhage in a traumatic brain injury patient taking dabigatran who was treated by administering idarucizumab.

Case presentation

A 72-year-old man was injured in a traffic accident and was transferred to our emergency room. On arrival, his Glasgow Coma Scale score was 14 (eye, 3; verbal, 5; motor, 6), and his other vital signs were stable. Computed tomography (CT) imaging on arrival showed a small intracranial hematoma. A second CT 3 h later revealed expansion of the hematoma. We received information that he was taking dabigatran only after the second CT. Idarucizumab was then promptly administered, and emergency craniotomy for hematoma removal was performed. There was no tendency for bleeding during the operation, and blood transfusion was not required during the perioperative period. Although the patient underwent additional surgery for subdural effusion and hydrocephalus, his postoperative course was uneventful. He was transferred to a rehabilitation hospital on postoperative day 102.

Conclusion

We managed a patient taking dabigatran who suffered traumatic intracranial hemorrhage by administering idarucizumab preoperatively without the need for blood transfusion perioperatively. We suggest that idarucizumab could be a potent therapeutic bridge to definitive surgical management in such patients with traumatic brain injury who are taking dabigatran.

Management of major bleeding and outcomes in patients treated with direct oral anticoagulants: results from the START-Event registry

The management of major bleeding in patients treated with direct oral anticoagulants (DOACs) is still not well established. START-Events, a branch of the START registry (Survey on anTicoagulated pAtients RegisTer) (NCT02219984), aims to describe the actual management of bleeding or recurrent thrombotic events in routine clinical practice. We here present the results of the management of bleeding patients. The START-Event registry is a prospective, observational, multicenter, international study. Baseline characteristics (demographic, clinical, risk factors) of patients, laboratory data at admission and during follow-up, site of bleeding, therapeutic strategies, and outcomes at the time of hospital discharge and after 6 months were recorded on a web-based case report form. Between January 2015 and December 2016, 117 patients with major bleeding events were enrolled. Non-valvular atrial fibrillation (NVAF) was the indication for treatment in 84% (62% males); 53 patients had intracranial bleeding (13 fatal), 42 had gastrointestinal bleeding (1 fatal), and 22 had bleeding in other sites. Therapeutic interventions for the management of bleeding were performed in 71% of patients. Therapeutic strategies with/without surgery or invasive procedures included: fluid replacement or red blood cells transfusion, prothrombin complex concentrates (3 or 4 factors), antifibrinolytic drugs, and the administration of idarucizumab. Creatinine, blood cell count, and PT/aPTT were the most frequent tests requested, while specific DOAC measurements were performed in 23% of patients. Mortality during hospitalization was 11.9%, at 6-month follow-up 15.5%. Our data confirm a high heterogeneity in the management of bleeding complications in patients treated with DOACs.

Non-Vitamin K Oral Anticoagulants Associated Bleeding and Its Antidotes

Oral anticoagulant-associated intracerebral hemorrhage (OAC-ICH) accounts for nearly 20% of all ICH. The number of patients with an indication for oral anticoagulant therapy (OAT) increases with increasing age. OAT became less complicate with the introduction of non-vitamin K oral anticoagulants (NOAC) OAT because of easier handling, favorable risk-benefit profile, reduced rates of ICH compared to vitamin K antagonists and no need for routine coagulation testing. Consequently, despite a better safety profile of NOAC the number of patients with OAC-ICH will increase. The mortality and complication rates of OAC-ICH are high and therefore they are the most feared complication of OAT. Immediate normalization of coagulation is the main goal and therefore knowledge of pharmacodynamics and coagulation status is essential. Laboratory measurements of anticoagulant activity in NOAC patients is challenging as specific tests are not widely available. More accessible tests such as the prothrombin time and activated partial thromboplastin time have important limitations. In dabigatran-associated ICH 5 g Idarucizumab should be administered. In rivaroxaban and apixaban-associated ICHs administration of andexanet alpha should be considered. Prothrombin complex concentrate may be considered if andexanet alpha is not available or in case of an ICH associated with edoxaban.

Consensus Guides on Stroke Thrombolysis for Anticoagulated Patients from Japan: Application to Other Populations

Development of direct oral anticoagulants and their antidotes has led to the need to reconsider the eligibility of acute stroke patients who have been taking oral anticoagulants for intravenous thrombolysis. Officially authorized Japanese guidelines on this issue were revised twice at the time of approval for clinical use of direct oral anticoagulants and idarucizumab, a specific reversal agent for dabigatran. A unique recommendation in the latest Japanese clinical guides was that thrombolysis can be recommended if the time of the last dose of direct oral anticoagulants exceeds 4 hours and if commonly available anticoagulation markers are normal or subnormal, i.e., international normalized ratio of prothrombin time <1.7 and activated partial thromboplastin time <1.5 times the baseline value (≤40 seconds only as a guide). These criteria are partly supported by the findings of domestic multicenter and single-center surveys that symptomatic or asymptomatic intracranial hemorrhage following thrombolysis was rare under the conditions of the criteria. Even for dabigatran users, stroke thrombolysis can be considered without pretreatment by idarucizumab if patients meet the above criteria. If not, direct mechanical thrombectomy can be considered without pretreatment by idarucizumab or thrombolysis, and use of idarucizumab, followed immediately by thrombolysis, can be considered only when thrombectomy cannot be quickly performed. These clinical guides are practical and to some extent economical, but they have some limitations, including lack of corroborating information from sufficient numbers of relevant cases. The guides will be further modified based on the results of future research.

Reversal of dabigatran-associated bleeding using idarucizumab: review of the current evidence

Major bleeding occurs in about 4% of patients while on treatment with direct oral anticoagulants (DOACs). The case-fatality rate associated with these events is estimated to be about 5%. The specific roles of antidotes, when used with DOACs in reducing the case fatality or improving the overall clinical course of these events, are not thoroughly understood. To this regard, the US Food and Drug Administration as well as European Medicines Agency have recently licensed idarucizumab for the management of patients with life-threatening bleeding or the need for urgent surgery/procedures while on treatment with dabigatran. Specifically, idarucizumab is a humanized monoclonal antibody fragment that rapidly reverses the anticoagulant effect of dabigatran. Two other antidotes, andeXanet and ciraparantag are currently under evaluation for reversal of DOACs. Here, we report on the use of idarucizumab in two patients who experienced life-threatening bleeding while on treatment with dabigatran for atrial fibrillation and provide a review highlighting the need for antidotes use with DOACs.

[Management of hemorrhage in patients treated with direct oral anticoagulants]

The introduction of nonvitamin K antagonistic, direct oral anticoagulants (DOAC) made thromboembolic prophylaxis easier for patients. For many physicians, however, there is still uncertainty about monitoring, preoperative discontinuation, and restarting of DOAC therapy. Guidelines for the management of bleeding are provided, but require specific therapeutic skills in the management of diagnostics and therapy of acute hemorrhage. Small clinical studies and case reports indicate that unspecific therapy with prothrombin complex concentrates (PCC) and activated PCC (aPCC) concentrate may reverse DOAC-induced anticoagulation. However, PCC or aPCC at higher doses potentially provoke thromboembolic complications. However, idarucizumab, a specific, fast-acting, antidote for dabigatran, provides immediate and sustained reversal with no intrinsic or prohemostatic activity. This review article provides an overview of the pharmacology and potential risk of DOAC and the management in the perioperative period with a focus of current concepts in the treatment of DOAC-associated bleeding.

Dabigatran-induced nephropathy and its successful treatment with Idarucizumab - case report and literature review

BACKGROUND

Anticoagulant induced renal injury has been previously described with Warfarin treatment. In the last decade direct oral anticoagulants (DOAC) were introduced. They include direct inhibitors of factor Xa (Rivaroxaban, Apixaban, Edoxaban) and a thrombin inhibitor (Dabigatran). There are isolated reports describing acute kidney injury (AKI) due to the use of DOACs.

CASE REPORT

We report a clinical case of an 80-year-old patient recently started on Dabigatran for new onset atrial fibrillation. She presented with AKI and hematuria, urine specimen showed RBC casts, and a working diagnosis of anticoagulant nephropathy due to Dabigatran was made. During hospitalization she was treated with Idarucizumab with a full recovery of renal function. To the best of our knowledge, there are 4 published case reports describing kidney injury produced by Dabigatran.

CONCLUSION

The use of DOACs is increasing rapidly, with increasing concern about its safety profile and, in particular, its potential harmful effect on renal function. As described in our case, treatment with Praxbind for Dabigatran induced kidney injury may be an acceptable management strategy that may obviate the need for urgent dialysis in selected cases by complete reversal of the AKI.

Successful treatment with idarucizumab for diffuse alveolar hemorrhage induced by dabigatran etexilate: a case report

We report the case of an 81-year-old man taking dabigatran etexilate (dabigatran) for chronic atrial fibrillation, who presented with acute-onset hemoptysis and hypoxia. Chest high-resolution computed tomography showed bilateral ground grass opacities. After admission, his respiratory failure progressed rapidly and bronchoalveolar lavage was performed immediately, which showed copious amounts of bloody fluid and hemosiderin-laden macrophages with Prussian blue staining. He was diagnosed as having diffuse alveolar hemorrhage (DAH). We therefore stopped dabigatran and initiated multimodality therapy including idarucizumab, which is a reversal agent for dabigatran. Clinical and radiological improvement was observed and he was discharged without any impairment. There has been no relapse of DAH since then. No abnormalities were detected on further investigation; finally, we concluded that his DAH was caused by dabigatran. This is the first known case of idarucizumab use for severe DAH caused by dabigatran. Our case suggested that dabigatran can cause life-threatening DAH; in such cases, administering idarucizumab could be an effective treatment option.

Safety and timing of resuming dabigatran after major gastrointestinal bleeding reversed by idarucizumab

The recent introduction of direct oral anticoagulants, including rivaroxaban, dabigatran, apixaban, and edoxaban, for the acute treatment and secondary prevention of venous thromboembolism and in atrial fibrillation has been shown to provide greater clinical benefit than oral vitamin K antagonists. However, direct oral anticoagulants are associated with adverse events, the most common being major bleeding; such events require the reversal of the anticoagulant effects by specific agents. In this case report, we describe an 87-year-old female with atrial fibrillation treated with dabigatran who had massive rectal bleeding. Idarucizumab 5 g (2 × 2.5 g/50 mL) was successfully used to reverse dabigatran effect; subsequent to this, treatment with dabigatran was resumed, and there were no further bleeding events. This suggests that dabigatran can be safely restarted after major bleeding, but this outcome needs to be confirmed in studies involving larger groups of patients.

[Anticoagulants: current topics]

Despite the introduction of direct oral anticoagulants (DOAC), the need for more effective and safer antithrombotic strategies exists. Recently, the findings stating that the contact system is important for thrombus formation has identified factor XI as a potential target for new anticoagulants. Approximately 20-30% of patients who develop venous thromboembolism (VTE) also have cancer. To date, the drugs primarily used in the treatment of VTE are heparin in the acute phase and warfarin in the chronic phase. Recently, a large-scale international clinical trial, which examined the composite outcomes of VTE recurrence and major bleeding in cancer patients, found that edoxaban, a direct factor Xa inhibitor, is not inferior to low-molecular-weight heparin. The study also showed that DOACs have a promising potential to prove therapeutically effective in future studies. Anticoagulants are associated with a severe side effect, bleeding, which makes emergency neutralization an important concern. Four-factor prothrombin complex concentrate can be used to reverse the effect of warfarin and could also be effective as a neutralizing agent in patients having received DOACs. Moreover, more specific reversing agents include the approved human monoclonal antibody fragment idarucizumab for reversing the effects of dabigatran.

Idarucizumab in High-risk Thoracic Surgery

Direct oral anticoagulants have suggested a favorable profile compared with vitamin K antagonists. However, the lack of treatment to reverse the effect of direct oral anticoagulants has limited its use in some patients who require rapid reversal of anticoagulation, as those included in the transplant waiting list. Idarucizumab is a recently approved drug to reverse the anticoagulant effect of dabigatran. However, the clinical experience when using this drug is scarce. Herein, we present a clinical case on anticoagulation reversal with idarucizumab to perform heart and lung transplantation in a patient with Eisenmenger syndrome.

Use of Idarucizumab for dabigatran reversal: Emergency department experience in two cases with subdural haematoma

Introduction

Idarucizumab is the first effective humanized monoclonal antibody fragment developed specifically as a reversal agent for dabigatran, a Direct Oral Anticoagulant. Despite recent trials demonstrating reversal of clinically relevant bleeding, there is a paucity of data on use outside the trial setting. This manuscript describes the use of Idarucizumab to reverse dabigatran in two patients presenting to the emergency department of a major tertiary hospital with acute traumatic subdural haematomas (SDH).

Methods

Patients were identified through retrospective review of medication dispensing systems and electronic medical records.

Results

Two cases of Idarucizumab use were identified. Case 1 was of a 63-year-old male who presented following a motorcycle crash. Case 2 was of a 77-year-old male who presented with a 3-week history of ataxia and recurrent falls. Both patients were taking dabigatran for atrial fibrillation (AF). CT Brain revealed acute SDH with clinical indications for urgent surgical evacuation. Serum dabigatran levels were obtained on arrival in the emergency department with levels of 155 ng/ml and 110 ng/ml (reference range 117–275 ng/ml). Idarucizumab for dabigatran reversal was commenced; Case 1 received 5 g Idarucizumab as an intravenous bolus dose, while Case 2 received 5 g Idarucizumab as two 2.5 g intravenous infusions. Serum dabigatran levels for Cases 1 and 2 were 0 ng/ml at 75 min and 340 min post Idarucizumab administration respectively. Both patients proceeded to craniotomy with evacuation of the SDH. There was no extension of the SDH in either case. Anticoagulation was withheld until outpatient clinic review, and both patients transferred for rehabilitation prior to discharge home.

Conclusion

Idarucizumab was clinically effective for reversing dabigatran, resulting in undetectable serum levels, and should be considered in patients presenting to hospital with clinically significant bleeding associated with dabigatran therapy.

Management of Elective Surgery and Emergent Bleeding with Direct Oral Anticoagulants

PURPOSE OF REVIEW

The purpose of this review was to offer practical management strategies for when patients receiving direct oral anticoagulants require elective surgery or present with bleeding complications.

RECENT FINDINGS

Clinical practice guidelines are now available on the timing of periprocedural interruption of treatment with the newer direct oral anticoagulants based on their pharmacodynamics and pharmacokinetics and based on findings from cohort studies and clinical trials. An antibody that reverses the effects of dabigatran is now available, and a factor Xa decoy is being developed as an antidote to apixaban, betrixaban, edoxaban, and rivaroxaban. The timing of interruption of direct oral anticoagulants for elective surgery is based on multiple factors, including pharmacologic properties and interactions, the patient's renal function, and the type of planned surgery. There is little role for low-molecular-weight heparin bridging. Idarucizumab is the treatment of choice for dabigatran-related life-threatening bleeding, while andexanet alfa is being developed to reverse factor Xa inhibitors.

Indications and Methods of Anticoagulation Reversal

The use of anticoagulation in the prevention of strokes due to atrial fibrillation or the treatment of venous thromboembolic disease has been on the rise. With the advent and proliferation of direct oral anticoagulation medications, the management of anticoagulation reversal has become increasingly complex, especially when urgent or emergent reversal is required. This review details the commonly used parenteral and oral anticoagulants, the treatment strategies necessary for their reversal, and therapies still in development.

Idarucizumab: What Should We Know?

BACKGROUND

Idarucizumab, a humanized monoclonal antibody fragment acting as a specific antidote for dabigatran, is approved for reversing the dabigatran-associated possible bleeding from critical sites or bleeding persisting despite local post-procedure haemostasis. Moreover, it can also be applied to reverse the dabigatran anticoagulant activity in emergency surgery or in other invasive procedure at high risk of bleeding.

OBJECTIVE

In this study, we discuss idarucizumab in light of the available literature data by conducting extensive research in the PubMed, EMBASE and Cochrane Library on the topic, using idarucizumab, dabigatran and their combinations as Mesh terms, and focusing on high impact investigations.

RESULTS

Several studies have demonstrated the capacity of idarucizumab to reverse laboratory measures of dabigatran-associated coagulopathy, however its efficacy and safety in real world patients are still not very clear because of the scarcity of available data which should be assessed with an extensive post market surveillance.

CONCLUSION

The introduction of idarucizumab as dabigatran antidote in clinical practice represents a useful tool for clinicians. The possibility to rapidly restore the anticoagulation activity of dabigatran makes its use simpler and more manageable.

Dabigatran reversal with idarucizumab in a patient undergoing heart transplantation: first European report

Background

Dabigatran is a direct thrombin inhibitor with a favorable effectiveness and safety profile when compared to vitamin K antagonists, both in randomized trials and real world registries of atrial fibrillation patients. Yet, physicians’ fear of high bleeding risk scenarios in daily clinical practice still precludes a more widespread use of oral anticoagulation. We hereby report a successful case of dabigatran reversal with the novel monoclonal antibody fragment idarucizumab in a patient undergoing heart transplantation.

Case presentation

A 45-year old male patient on dabigatran for atrial fibrillation thromboprophylaxis was enlisted for heart transplantation due to end-stage ischemic heart failure. Upon donor availability and suitability and following the last intake of the drug 12 h previously, activated partial thromboplastin time was measured and found to be elevated. After general anesthesia and before extracorporeal circulation, idarucizumab was administered as two boluses of 2.5 g. Orthotopic heart transplantation ensued under full heparinization and cardiopulmonary bypass. Total chest tube output was 1125 mL after 3 days and 4 units of fresh frozen plasma and one platelet pool were administered in the operating room without further need for blood products. The post-operative period was uneventful.

Conclusions

Idarucizumab was associated with an effective hemostasis in the setting of heart transplantation. Dabigatran may be considered as an alternative to vitamin K antagonists in heart transplant candidates with an indication for oral anticoagulation.