Difficult Intraoperative Heparinization Following Andexanet Alfa Administration

Direct oral anticoagulants are now commonplace, and reversal agents are recently becoming available. Andexanet alfa (AnXa), approved by the United States Food and Drug Administration in 2018, is a novel decoy molecule that reverses factor Xa inhibitors in patients with major hemorrhage. We present a case of a 70-year-old man taking rivaroxaban with hemodynamic instability from a ruptured abdominal aortic aneurysm. He received AnXa prior to endovascular surgery, and intraoperatively he could not be heparinized for graft placement. Consideration should be given to the risks and benefits of AnXa administration in patients who require anticoagulation after hemorrhage has been controlled.

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Reversal Strategies for Intracranial Hemorrhage Related to Direct Oral Anticoagulant Medications

Critical Care Research and Practice ◽

10.1155/2018/4907164 ◽

2018 ◽

Vol 2018 ◽

pp. 1-11 ◽

Cited By ~ 7

Author(s):

Alok Dabi ◽

Aristides P. Koutrouvelis

Keyword(s):

Side Effects ◽

Intracranial Hemorrhage ◽

Vitamin K Antagonists ◽

Oral Anticoagulants ◽

Direct Oral Anticoagulants ◽

Factor Xa ◽

Coagulation Cascade ◽

Reversal Agents ◽

United States Food ◽

Life Threatening

Direct oral anticoagulants (DOACs) are a new class of anticoagulants that directly inhibit either thrombin or factor Xa in the coagulation cascade. They are being increasingly used instead of warfarin or other vitamin K antagonists (VKAs). Adverse side effects of DOACs may result in hemorrhagic complications, including life-threatening intracranial hemorrhage (ICH), though to a much lesser degree than VKAs. Currently there are relatively limited indications for DOACS but their usage is certain to expand with the availability of their respective specific reversal agents. Currently, only idarucizumab (antidote for dabigatran) has been United States Food and Drug Administration- (FDA-) approved, but others (andexanet-α and ciraparantag) may be approved in near future, and the development and availability of such reversal agents have the potential to dramatically change the current anticoagulant use by providing reversal of multiple oral anticoagulants. Until all the DOACs have FDA-approved reversal agents, the treatment of the dreaded side effects of bleeding is challenging. This article is an attempt to provide an overview of the management of hemorrhage, especially ICH, related to DOAC use.

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Andexanet alfa for reversal of factor Xa inhibitors: a critical review of the evidence

Future Cardiology ◽

10.2217/fca-2019-0038 ◽

2019 ◽

Vol 15 (6) ◽

pp. 395-404

Author(s):

Jameel Abdulrehman ◽

John W Eikelboom ◽

Deborah M Siegal

Keyword(s):

Vitamin K Antagonists ◽

Oral Anticoagulants ◽

Direct Oral Anticoagulants ◽

Factor Xa ◽

Factor Xa Inhibitors ◽

Activity Levels ◽

Reversal Agents ◽

Life Threatening ◽

Andexanet Alfa ◽

Anticoagulated Patients

Direct oral anticoagulants are associated with lower rates of bleeding than vitamin K antagonists, but life-threatening bleeding still occurs. Andexanet alfa is a catalytically inactive recombinant modified human factor Xa molecule that reverses the anticoagulant effect of direct and indirect acting factor Xa inhibitors. In the ANNEXA-4 study, treatment with andexanet was associated with a 92% reduction in median anti-Xa activity levels and excellent or good hemostasis in 82% of patients presenting with serious bleeding while receiving apixaban or rivaroxaban. In this review, we discuss the burden of bleeding in anticoagulated patients and the need for reversal agents, review the mechanism of action of andexanet and critically evaluate the evidence for its efficacy and safety.

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A Review on the Use of Reversal Agents of Direct Oral Anticogulant Drugs in Case of Gastrointestinal Bleeding

Reviews on Recent Clinical Trials ◽

10.2174/1574887115666200624193938 ◽

2020 ◽

Vol 15 ◽

Author(s):

Veronica Ojetti ◽

Angela Saviano ◽

Mattia Brigida ◽

Luisa Saviano ◽

Alessio Migneco ◽

...

Keyword(s):

Gastrointestinal Bleeding ◽

Major Bleeding ◽

Oral Anticoagulants ◽

Direct Oral Anticoagulants ◽

Medical Emergency ◽

Management Approach ◽

Emergency Setting ◽

Reversal Agents ◽

Life Threatening ◽

Andexanet Alfa

Background : Major bleeding is a life-threatening condition and a medical emergency with high mortality risk. It is often the complication of anticoagulant’s intake. Anticoagulants are commonly used for the prevention and the treatment of thrombotic events. The standard therapy with vitamin K antagonist (warfarin) has been frequently replaced by direct oral anticoagulants (DOACs). The latter agents (rivaroxaban, apixaban, edoxaban, dabigatran, betrixaban) showed a better efficacy and safety compared to standard warfarin treatment and they are recommended for the reduction of ischemic stroke. Literature data reported a high risk of gastrointestinal bleeding with DOACs, in particular with dabigatran and rivaroxaban. In case of life-threatening gastrointestinal bleeding, these patients could benefit from the use of reversal agents. Methods: We performed an electronic search on PUBMED of the literature concerning reversal agents for DOACs and gastrointestinal bleeding in the Emergency Department from 2004 to 2020. AIM: This review summarizes the current evidences about three reversal agents idarucizumab, andexanet alfa and ciraparantag, and the use of the first two in the emergency setting in patients with an active major bleeding or who need urgent surgery to offer physicians indications for a better management approach in order to increase patient’s safety. Conclusion: Although these agents have been marketed for five years (idarucizumab) and two years (andexanet alfa) respectively, and despite guidelines considering antidotes as first-line agents in treating life-threatening hemorrhage when available, these antidotes seem to gain access very slowly in the clinical practice. Cost, logistical aspects and need for plasma level determination of DOAC for an accurate therapeutic use probably have an impact on this phenomenon.. An expert multidisciplinary bleeding team should be established so as to implement international guidelines based on local resources and organization.

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Abstract MP38: Intracerebral Hemorrhage Across the United States: Incidence and Mortality Trends From 1990 to 2017

Stroke ◽

10.1161/str.52.suppl_1.mp38 ◽

2021 ◽

Vol 52 (Suppl_1) ◽

Author(s):

Augustin DeLago ◽

Harpreet Singh ◽

Arashdeep Rupal ◽

Chinmay Jani ◽

Arshi Parvez ◽

...

Keyword(s):

United States ◽

Intracerebral Hemorrhage ◽

Vitamin K Antagonists ◽

Oral Anticoagulants ◽

Direct Oral Anticoagulants ◽

The United States ◽

Mortality Trends ◽

Reversal Agents ◽

Incidence And Mortality ◽

The Us

Background: Intracerebral Hemorrhage (ICH) accounts for 10% of strokes annually in the United States (US). Up-to-date trends in disease burden and regional variation remain unknown; especially after a dramatic increase in the use of direct oral anticoagulants (DOACs) since 2010. Our study reports updated incidence, mortality and mortality to incidence ratio (MIR) data related to ICH across the US. Methods: This observational study utilized the Global Burden of Disease database to determine age-standardized incidence (ASIR), death (ASDR) and MIR rates for ICH overall and for each state in the US from 1990-2017. All analyses were stratified by sex. Trends were analyzed using Joinpoint regression analysis, with presentation of estimated annual percentage changes (EAPCs) in ASIRs, ASDRs and MIRs over the observation period. Results: We observed an overall decrease in ASIRs, ASDRs and MIRs in both genders from 1990-2017, apart from female ASIRs and ASDRs in West Virginia and Kentucky. In 2017, the mean ASIR per 100,000 population for men was 25.67 and 19.17 for women. The 2017 mean ASDRs per 100,000 population for men and women were 13.96 and 11.35, respectively. The District of Columbia had the greatest decreases in ASIR EAPCs for males at -41.25% and females at -40.58%, and the greatest decreases in ASDR EAPCs for both males and females at -55.38% and -48.51%, respectively. The overall MIR during the study period decreased in males by -12.12% and females by -7.43%. However, MIR increased in males from 2014-2017 (EAPC +2.2% [95% CI +0.9%-+3.5%]) and in females from 2011-2017 (EAPC +1.0% [CI +0.7%-+1.4%]). Conclusion: This report reveals overall decreasing trends in incidence, mortality and MIR from 1990-2017. Notably, no significant change in mortality was found in the last 6 years of the study period, and MIR worsened in males from 2014-2017 and in females from 2011-2017, suggesting decreased ICH related survival lately. The substitution of vitamin K antagonists with DOACs is one possible explanation for a downtrend in incidence despite an aging population and increased use of anticoagulants. Limited access to reversal agents for DOACs is a potential reason for increase in MIR, however concrete deductions cannot be made owing to the observational nature of the study.

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Reversal of direct oral anticoagulants: a practical approach

Hematology ◽

10.1182/asheducation-2016.1.612 ◽

2016 ◽

Vol 2016 (1) ◽

pp. 612-619 ◽

Cited By ~ 16

Author(s):

Andrew W. Shih ◽

Mark A. Crowther

Keyword(s):

Phase 1 ◽

Oral Anticoagulants ◽

Direct Oral Anticoagulants ◽

Antibody Fragment ◽

Factor Xa ◽

Factor Xa Inhibitors ◽

Severe Bleeding ◽

Thrombin Time ◽

Ancillary Benefits ◽

Reversal Agents

Abstract Direct oral anticoagulants (DOACs) have at least noninferior efficacy compared with other oral anticoagulants and have ancillary benefits, including overall better safety profiles, lack of the need for routine monitoring, rapid onset of action, and ease of administration. Reversal of these agents may be indicated in certain situations such as severe bleeding and for perioperative management. DOAC-associated bleeding should be risk stratified: patients with moderate or severe bleeding should have the DOAC discontinued and reversal strategies should be considered. Laboratory testing has limited utility in the acute management of bleeding; thrombin time and activated partial thromboplastin time may be useful for excluding clinically relevant levels of dabigatran. Prothrombin time is potentially useful for rivaroxaban and edoxaban, but calibrated anti-Xa assays are optimal for determining clinically relevant levels of factor Xa inhibitors. Because specific reversal agents are not widely available, supportive care and interventions for local hemostasis remain the cornerstones of therapy in the patient with DOAC-associated bleeding. Nonspecific reversal agents should be considered only in the event of severe bleeding because their efficacy is unknown, and they are associated with risk of thrombosis. Recent results from phase 3/4 studies demonstrate efficacy for an antidote to dabigatran (idarucizumab, a monoclonal antibody fragment with specificity for dabigatran) and an antidote to factor Xa inhibitors (andexanet alfa, a recombinant and inactive form of factor Xa that binds inhibitors). A universal reversal agent (ciraparantag) for many anticoagulants, including the DOACs, shows promise in results from phase 1 and 2 studies.

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Monitoring and reversal of direct oral anticoagulants

Hematology ◽

10.1182/asheducation.v2015.1.117.3916182 ◽

2015 ◽

Vol 2015 (1) ◽

pp. 117-124 ◽

Cited By ~ 5

Author(s):

Adam Cuker ◽

Deborah Siegal

Keyword(s):

Prothrombin Complex Concentrate ◽

Oral Anticoagulants ◽

Direct Oral Anticoagulants ◽

Antibody Fragment ◽

Factor Xa ◽

Factor Xa Inhibitors ◽

Severe Bleeding ◽

Thrombin Time ◽

Reversal Agents ◽

Routine Monitoring

Abstract Although the direct oral anticoagulants (DOACs) do not require routine monitoring and reduce bleeding compared with warfarin, there are special circumstances in which laboratory measurement or reversal of their anticoagulant effect may be indicated. The dilute thrombin time and ecarin-based assays are able to quantify dabigatran across a broad range of concentrations, but are not widely available. A normal thrombin time excludes clinically relevant levels and a normal activated partial thromboplastin time probably excludes excess levels of dabigatran. Factor Xa inhibitors may be quantified with an anti-Xa assay calibrated with drug-specific standards. A normal prothrombin time probably excludes excess levels of rivaroxaban and edoxaban, but not apixaban. Patients with minor and moderate DOAC-associated bleeding can be treated with supportive care and general hemostatic measures. Nonspecific reversal agents (eg, prothrombin complex concentrate, activated prothrombin complex concentrate) are of unproven benefit, carry a risk of thrombosis, and should be reserved for severe bleeding. Specific reversal agents, such as idarucizumab (a monoclonal antibody fragment that binds dabigatran) and andexanet alfa (a recombinant factor Xa variant that binds factor Xa inhibitors but lacks coagulant activity), are in clinical development.

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Managing reversal of direct oral anticoagulants in emergency situations

Thrombosis and Haemostasis ◽

10.1160/th16-05-0363 ◽

2016 ◽

Vol 116 (12) ◽

pp. 1003-1010 ◽

Cited By ~ 28

Author(s):

Harry R. Büller ◽

Anna Falanga ◽

Werner Hacke ◽

Jeroen Hendriks ◽

Trudie Lobban ◽

...

Keyword(s):

Task Force ◽

Oral Anticoagulants ◽

Direct Oral Anticoagulants ◽

Factor Xa ◽

Therapeutic Benefit ◽

Current Status ◽

Reversal Agent ◽

Medical Specialties ◽

Reversal Agents ◽

Emergency Situations

SummaryAnticoagulation is the cornerstone of prevention and treatment of venous thromboembolism (VTE) and stroke prevention in patients with atrial fibrillation (AF). However, the mechanisms by which anticoagulants confer therapeutic benefit also increase the risk of bleeding. As such, reversal strategies are critical. Until recently, the direct oral anticoagulants (DOACs) dabigatran, rivaroxaban, apixaban, and edoxaban lacked a specific reversal agent. This report is based on findings from the Anticoagulation Education Task Force, which brought together patient groups and professionals representing different medical specialties with an interest in patient safety and expertise in AF, VTE, stroke, anticoagulation, and reversal agents, to discuss the current status of anticoagulation reversal and fundamental changes in management of bleeding associated with DOACs occasioned by the approval of idarucizumab, a specific reversal agent for dabigatran, as well as recent clinical data on specific reversal agents for factor Xa inhibitors. Recommendations are given for when there is a definite need for a reversal agent (e.g. in cases of life-threatening bleeding, bleeding into a closed space or organ, persistent bleeding despite local haemostatic measures, and need for urgent interventions and/or interventions that carry a high risk for bleeding), when reversal agents may be helpful, and when a reversal agent is generally not needed. Key stakeholders who require 24–7/around-the-clock access to these agents vary among hospitals; however, from a practical perspective the emergency department is recommended as an appropriate location for these agents. Clearly, the advent of new agents requires standardised protocols for treating bleeding on an institutional level.

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Monitoring and reversal of direct oral anticoagulants

Hematology ◽

10.1182/asheducation-2015.1.117 ◽

2015 ◽

Vol 2015 (1) ◽

pp. 117-124 ◽

Cited By ~ 31

Author(s):

Adam Cuker ◽

Deborah Siegal

Keyword(s):

Prothrombin Complex Concentrate ◽

Oral Anticoagulants ◽

Direct Oral Anticoagulants ◽

Antibody Fragment ◽

Factor Xa ◽

Factor Xa Inhibitors ◽

Severe Bleeding ◽

Thrombin Time ◽

Reversal Agents ◽

Routine Monitoring

Although the direct oral anticoagulants (DOACs) do not require routine monitoring and reduce bleeding compared with warfarin, there are special circumstances in which laboratory measurement or reversal of their anticoagulant effect may be indicated. The dilute thrombin time and ecarin-based assays are able to quantify dabigatran across a broad range of concentrations, but are not widely available. A normal thrombin time excludes clinically relevant levels and a normal activated partial thromboplastin time probably excludes excess levels of dabigatran. Factor Xa inhibitors may be quantified with an anti-Xa assay calibrated with drug-specific standards. A normal prothrombin time probably excludes excess levels of rivaroxaban and edoxaban, but not apixaban. Patients with minor and moderate DOAC-associated bleeding can be treated with supportive care and general hemostatic measures. Nonspecific reversal agents (eg, prothrombin complex concentrate, activated prothrombin complex concentrate) are of unproven benefit, carry a risk of thrombosis, and should be reserved for severe bleeding. Specific reversal agents, such as idarucizumab (a monoclonal antibody fragment that binds dabigatran) and andexanet alfa (a recombinant factor Xa variant that binds factor Xa inhibitors but lacks coagulant activity), are in clinical development.

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What we have learned about direct oral anticoagulant reversal

Hematology ◽

10.1182/hematology.2019000072 ◽

2019 ◽

Vol 2019 (1) ◽

pp. 198-203 ◽

Cited By ~ 3

Author(s):

Deborah M. Siegal

Keyword(s):

Oral Anticoagulant ◽

Oral Anticoagulants ◽

Direct Oral Anticoagulants ◽

Management Strategies ◽

Factor Xa ◽

Case Fatality ◽

Bleeding Complications ◽

Major Health Problem ◽

Reversal Agents ◽

Anticoagulant Reversal

Abstract Bleeding is the main complication of oral anticoagulant (OAC) therapy, with major bleeds occurring in about 2% to 4% of OAC-treated patients per year. Although direct oral anticoagulants (DOACs) reduce the risk of major, fatal, and intracranial hemorrhage, major DOAC-related bleeding is associated with substantial morbidity and mortality, with case-fatality rates of 8% to 15% reported. Specific reversal agents for dabigatran (idarucizumab) and factor Xa inhibitors (andexanet) correct laboratory indices of anticoagulant effect. Clinical studies suggest that the majority of patients receiving these agents for DOAC-associated major bleeds experience clinical hemostasis. However, uncertainty remains regarding the incremental benefit of these agents and prothrombin complex concentrates over supportive measures alone, based on cohort studies that lacked control groups. Similar methodologic limitations preclude firm conclusions regarding the harms associated with use of these agents. Importantly, patients with DOAC-related major bleeding have substantial short-term risks of thrombosis and mortality, emphasizing the need for individualized patient assessment and protocolized bleed management strategies that include assessment of candidacy for safe resumption of OACs. With expanding indications and increasing prevalence of DOAC-eligible patients, bleeding complications and their management represent an ever-greater major health problem.

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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

Journal of Clinical Medicine ◽

10.3390/jcm10163476 ◽

2021 ◽

Vol 10 (16) ◽

pp. 3476

Author(s):

Daniel Oberladstätter ◽

Christoph J. Schlimp ◽

Johannes Zipperle ◽

Marcin F. Osuchowski ◽

Wolfgang Voelckel ◽

...

Keyword(s):

Plasma Concentration ◽

Healthy Volunteers ◽

Oral Anticoagulants ◽

Direct Oral Anticoagulants ◽

Factor Xa ◽

Factor Xa Inhibitors ◽

Clotting Time ◽

Andexanet Alfa ◽

The Impact

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.

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