Management of Severe Bleeding in Patients Treated with Direct Oral Anticoagulants

Latest advances in the reversal strategies for direct oral anticoagulants

BACKGROUND

Since the late 2000s, Europe has granted approval for various thrombotic risk-related uses of direct oral anticoagulants (DOACs). Unlike traditional anticoagulants, DOACs do not necessitate routine coagulation monitoring. Nevertheless, clinical practice often encounters bleeding events associated with these medications, making the need for effective reversal strategies evident.

OBJECTIVES

The study aims to take stock of current reversal strategies for DOACs, with a particular emphasis on the latest compounds that have been developed or are currently under development.

METHODS

For obtaining information regarding the ongoing reversal strategies and the compounds under development, we referred to ClinicalTrials website, PubMed, and Google Scholar.

RESULTS

In 2024, two specific antidotes to DOACs have already received approval when reversal of anticoagulation is needed owing to life-threatening or uncontrolled bleeding: idarucizumab that reverses the effects of dabigatran, and andexanet alfa, designed to counteract activated factor X inhibitors such as apixaban and rivaroxaban. Furthermore, ciraparantag, a potential universal reversal agent, is currently in advanced stages of clinical development. Concerns remain regarding the safety of specific reversal agents, especially concerning the risk of thrombosis. Additionally, the cost of these antidotes remains high. Consequently, nonspecific strategies to counteract anticoagulant medications, including activated charcoal, hemodialysis, and concentrates of coagulation factors, still have utility.

CONCLUSION

With the validation of specific and nonspecific antidotes, DOACs could supplant traditional oral anticoagulants. This progress represents a significant advancement in anticoagulation therapy. However, ongoing research is crucial to address remaining safety concerns of the specific reversion agents of DOACs in clinical practice.

The impact of ABCB1, CYP3A4 and CYP3A5 gene polymorphisms on apixaban trough concentration and bleeding risk in patients with atrial fibrillation

OBJECTIVES

Apixaban, a direct oral anticoagulant, is increasingly used worldwide for the treatment and prevention of venous thromboembolism and ischemic stroke in patients with nonvalvular atrial fibrillation (AF). Obviously, one of the ways to enhance effectiveness and safety of drug therapy is a personalized approach to therapy, which involves pharmacogenetic and pharmacokinetic tests. The study aims to investigate the effect of CYP3A4*22, CYP3A5*3 and ABCB1 polymorphisms on the pharmacokinetics of apixaban and the risk of bleeding.

METHODS

A total of 84 patients were enrolled in this prospective observational study. All patients received apixaban 5 or 2.5 mg twice daily. Real-time polymerase chain reaction was used to evaluate single-nucleotide polymorphisms of the ABCB1 gene (rs1045642 and rs4148738), CYP3A4*22 (rs35599367) C>T, CYP3A5*3 (rs776746) A>G. A plasma trough concentration/dose (C/D) ratio was used as a pharmacokinetic index.

RESULTS

The C/D ratio was higher in patients aged >80 years (F(1)=11.209, p=0.00124) and was affected by serum creatinine (>133 μmol/L, F(1)=6.7, p=0.01124). ABCB1 (rs1045642 and rs4148738), CYP3A5 (rs776746) and CYP3A4 (rs35599367) polymorphisms did not show a correlation with C/D ratio of apixaban. Multivariate logistic regression analyses showed that none of the clinical or genetic factors predicted the fact of bleeding.

CONCLUSIONS

We report no significant association between ABCB1 gene polymorphisms (rs1045642 and rs4148738), CYP3A4*22 (rs35599367) C>T, CYP3A5*3 (rs776746) A>G and bleeding events on apixaban treatment. Complementing the existing criteria with pharmacogenetic and pharmacokinetics information for the patients with AF will enable further individualization of apixaban.

Clinical guideline on reversal of direct oral anticoagulants in patients with life threatening bleeding

BACKGROUND

Anticoagulation is essential for the treatment and prevention of thromboembolic events. Current guidelines recommend direct oral anticoagulants (DOACs) over vitamin K antagonists in DOAC-eligible patients. The major complication of anticoagulation is serious or life-threatening haemorrhage, which may necessitate prompt haemostatic intervention. Reversal of DOACs may also be required for patients in need of urgent invasive procedures. This guideline from the European Society of Anaesthesiology and Intensive Care (ESAIC) aims to provide evidence-based recommendations and suggestions on how to manage patients on DOACs undergoing urgent or emergency procedures including the treatment of DOAC-induced bleeding.

DESIGN

A systematic literature search was performed, examining four drug comparators (dabigatran, rivaroxaban, apixaban, edoxaban) and clinical scenarios ranging from planned to emergency surgery with the outcomes of mortality, haematoma growth and thromboembolic complications. The GRADE (Grading of Recommendations, Assessment, Development and Evaluation) methodology was used to assess the methodological quality of the included studies. Consensus on the wording of the recommendations was achieved by a Delphi process.

RESULTS

So far, no results from prospective randomised trials comparing two active comparators (e.g. a direct reversal agent and an unspecific haemostatic agent such as prothrombin complex concentrate: PCC) have been published yet and the majority of publications were uncontrolled and observational studies. Thus, the certainty of evidence was assessed to be either low or very low (GRADE C). Thirty-five recommendations and clinical practice statements were developed. During the Delphi process, strong consensus (>90% agreement) was achieved in 97.1% of recommendations and consensus (75 to 90% agreement) in 2.9%.

DISCUSSION

DOAC-specific coagulation monitoring may help in patients at risk for elevated DOAC levels, whereas global coagulation tests are not recommended to exclude clinically relevant DOAC levels. In urgent clinical situations, haemostatic treatment using either the direct reversal or nonspecific haemostatic agents should be started without waiting for DOAC level monitoring. DOAC levels above 50 ng ml-1 may be considered clinically relevant necessitating haemostatic treatment before urgent or emergency procedures. Before cardiac surgery under activated factor Xa (FXa) inhibitors, the use of andexanet alfa is not recommended because of inhibition of unfractionated heparin, which is needed for extracorporeal circulation. In the situation of DOAC overdose without bleeding, no haemostatic intervention is suggested, instead measures to eliminate the DOACs should be taken. Due to the lack of published results from comparative prospective, randomised studies, the superiority of reversal treatment strategy vs. a nonspecific haemostatic treatment is unclear for most urgent and emergency procedures and bleeding. Due to the paucity of clinical data, no recommendations for the use of recombinant activated factor VII as a nonspecific haemostatic agent can be given.

CONCLUSION

In the clinical scenarios of DOAC intake before urgent procedures and DOAC-induced bleeding, practitioners should evaluate the risk of bleeding of the procedure and the severity of the DOAC-induced bleeding before initiating treatment. Optimal reversal strategy remains to be determined in future trials for most clinical settings.

Acute coronary syndrome in patients treated by vitamin K antagonists or non-vitamin K antagonist oral anticoagulants: Proposed management algorithm for the first 48hours

Around 10% of patients with acute coronary syndrome are treated by vitamin K antagonists or non-vitamin K antagonist oral anticoagulants for various indications. The initial management of these patients is highly complex, and new guidelines specify that, only during percutaneous coronary intervention, a bolus of unfractionated heparin is recommended in one of the following circumstances: (1) if the patient is receiving a non-vitamin K antagonist oral anticoagulant; or (2) if the international normalized ratio is<2.5 in a patient being treated with a vitamin K antagonist. In this review, we report on five key messages essential for the management of these patients. There are no randomized studies to date, and we propose two diagnostic and/or therapeutic decision algorithms. However, randomized studies are needed to validate these strategies.

Pharmacokinetic and Pharmacogenetic Predictors of Major Bleeding Events in Patients with an Acute Coronary Syndrome and Atrial Fibrillation Receiving Combined Antithrombotic Therapy

Objective: This study's objective was to evaluate the effects of pharmacokinetic and pharmacogenetic factors on major bleeding in patients with ACS and non-valvular AF receiving combined antithrombotic therapy consisting of rivaroxaban, clopidogrel, and aspirin as part of dual or triple therapy. Methods: A prospective observational study was conducted in two PCI centers in Moscow, the Russian Federation, from 2017 to 2018. One hundred patients with ACS and AF were enrolled. Prospective follow-ups continued for 12 months. Results: A total of 36 patients experienced bleeding events, with 10 experiencing major bleeding based on the BARC scale and 17 experiencing major bleeding based on the ISTH scale. The following predictors associated with an increased number of major bleeding events were identified: for the ISTH scale, a Css min. of rivaroxaban of >137 pg/mL (5.94 OR, (95% CI, 3.13-12.99; p < 0.004)) and carriage of the T allelic variant polymorphism ABCB1 rs4148738 (8.97 OR (95% CI, 1.48-14.49; p < 0.017)), as well as for the BARC scale (5.76 OR (95% CI, 2.36-9.87; p < 0.018)). Conclusions: Measuring residual steady-state rivaroxaban concentrations and determining the carriage of the T allelic variant polymorphism ABCB1 rs4148738 may be applicable to high-risk patients for subsequent antithrombotic therapy modification.

Extracranial anticoagulant related bleedings admitted to intensive care units: a French multicenter retrospective study

BACKGROUND

Anticoagulants are widely used but can lead to iatrogenic events such as bleeding. Limited data exists regarding the characteristics and management of patients admitted to intensive care units (ICU) for severe anticoagulant-related extracranial bleeding.

METHODS

A retrospective observational study was conducted in five French ICUs. From January 2007 to December 2018, all patients aged over 18 years admitted to ICU for extracranial bleeding while receiving therapeutic anticoagulation were included.

RESULTS

486 patients were included, mainly male (61%) with an average age of 73 ± 13 years. Most patients had comorbidities, including hypertension (68%), heart disease (49%) and diabetes (33%). Patients were treated by vitamin K antagonists (VKA, 54%), heparins (25%) and direct oral anticoagulants (DOAC, 7%). The incidence of patients admitted to ICU for anticoagulant-related bleeding increased from 3.2/1000 admissions in 2007 to 5.8/1000 in 2018. This increase was particularly high for DOAC class. Upon admission, patients exhibited severe organ failure, as evidenced by a high SOFA score (7 ± 4) and requirement for organ support therapies such as vasopressors (31.5%) and invasive mechanical ventilation (34%). Adherence to guidelines for the specific treatment of anticoagulant-related bleeding was generally low. ICU mortality was 27%. In multivariate analysis, five factors were independently associated with mortality: chronic hypertension, need for vasopressors, impaired consciousness, hyperlactatemia and prolonged aPTT > 1.2.

CONCLUSION

Anticoagulant-related extracranial bleeding requiring ICU admission is a serious complication responsible for organ failure and significant mortality. Its incidence is rising. The therapeutic management is suboptimal and could be improved by educational programs.

Direct oral anticoagulants or vitamin K antagonists in emergencies: comparison of management in an observational study

Background

Restoring hemostasis in patients on oral anticoagulants presenting with major hemorrhage (MH) or before surgical intervention has changed, with the replacement of vitamin K antagonist (VKA) with direct oral anticoagulants (DOACs).

Objectives

To observe the difference in urgent hemostatic management between patients on VKA and those on DOACs.

Methods

A multicenter observational study evaluated the variation in laboratory testing, hemostatic management, mortality, and hospital length of stay (LOS) in patients on VKA or DOACs presenting with MH or urgent hemostatic restoration.

Results

Of the 1194 patients analyzed, 783 had MH (61% VKA) and 411 required urgent hemostatic restoration before surgery (56% VKA). Compared to the international normalized ratio (97.6%), plasma DOAC levels were measured less frequently (<45%), and the time taken from admission for the coagulation sample to reach the laboratory varied widely (median, 52.3 minutes; IQR, 24.8-206.7). No significant plasma DOAC level (<50 ng/mL) was found in up to 19% of patients. There was a poor relationship between plasma DOAC level and the usage of a hemostatic agent. When compared with patients receiving VKA (96.5%) or dabigatran (93.7%), fewer patients prescribed a factor Xa inhibitor (75.5%) received a prohemostatic reversal agent. The overall 30-day mortality for MH (mean: 17.8%) and length of stay (LOS) (median: 8.7 days) was similar between VKA and DOAC patients.

Conclusion

In DOAC patients, when compared to those receiving VKA, plasma DOAC levels were measured less frequently than the international normalized ratio and had a poor relationship with administering a hemostatic reversal agent. In addition, following MH, mortality and LOS were similar between VKA and DOAC patients.

Management of severe peri-operative bleeding: Guidelines from the European Society of Anaesthesiology and Intensive Care: Second update 2022

BACKGROUND

Management of peri-operative bleeding is complex and involves multiple assessment tools and strategies to ensure optimal patient care with the goal of reducing morbidity and mortality. These updated guidelines from the European Society of Anaesthesiology and Intensive Care (ESAIC) aim to provide an evidence-based set of recommendations for healthcare professionals to help ensure improved clinical management.

DESIGN

A systematic literature search from 2015 to 2021 of several electronic databases was performed without language restrictions. Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used to assess the methodological quality of the included studies and to formulate recommendations. A Delphi methodology was used to prepare a clinical practice guideline.

RESULTS

These searches identified 137 999 articles. All articles were assessed, and the existing 2017 guidelines were revised to incorporate new evidence. Sixteen recommendations derived from the systematic literature search, and four clinical guidances retained from previous ESAIC guidelines were formulated. Using the Delphi process on 253 sentences of guidance, strong consensus (>90% agreement) was achieved in 97% and consensus (75 to 90% agreement) in 3%.

DISCUSSION

Peri-operative bleeding management encompasses the patient's journey from the pre-operative state through the postoperative period. Along this journey, many features of the patient's pre-operative coagulation status, underlying comorbidities, general health and the procedures that they are undergoing need to be taken into account. Due to the many important aspects in peri-operative nontrauma bleeding management, guidance as to how best approach and treat each individual patient are key. Understanding which therapeutic approaches are most valuable at each timepoint can only enhance patient care, ensuring the best outcomes by reducing blood loss and, therefore, overall morbidity and mortality.

CONCLUSION

All healthcare professionals involved in the management of patients at risk for surgical bleeding should be aware of the current therapeutic options and approaches that are available to them. These guidelines aim to provide specific guidance for bleeding management in a variety of clinical situations.

Regional anaesthesia in patients on antithrombotic drugs: Joint ESAIC/ESRA guidelines

BACKGROUND

Bleeding is a potential complication after neuraxial and peripheral nerve blocks. The risk is increased in patients on antiplatelet and anticoagulant drugs. This joint guideline from the European Society of Anaesthesiology and Intensive Care and the European Society of Regional Anaesthesia aims to provide an evidence-based set of recommendations and suggestions on how to reduce the risk of antithrombotic drug-induced haematoma formation related to the practice of regional anaesthesia and analgesia.

DESIGN

A systematic literature search was performed, examining seven drug comparators and 10 types of clinical intervention with the outcome being peripheral and neuraxial haematoma. Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used for assessing the methodological quality of the included studies and for formulating recommendations. A Delphi process was used to prepare a clinical practice guideline.

RESULTS

Clinical studies were limited in number and quality and the certainty of evidence was assessed to be GRADE C throughout. Forty clinical practice statements were formulated. Using the Delphi-process, strong consensus (>90% agreement) was achieved in 57.5% of recommendations and consensus (75 to 90% agreement) in 42.5%.

DISCUSSION

Specific time intervals should be observed concerning the adminstration of antithrombotic drugs both prior to, and after, neuraxial procedures or those peripheral nerve blocks with higher bleeding risk (deep, noncompressible). These time intervals vary according to the type and dose of anticoagulant drugs, renal function and whether a traumatic puncture has occured. Drug measurements may be used to guide certain time intervals, whilst specific reversal for vitamin K antagonists and dabigatran may also influence these. Ultrasound guidance, drug combinations and bleeding risk scores do not modify the time intervals. In peripheral nerve blocks with low bleeding risk (superficial, compressible), these time intervals do not apply.

CONCLUSION

In patients taking antiplatelet or anticoagulant medications, practitioners must consider the bleeding risk both before and after nerve blockade and during insertion or removal of a catheter. Healthcare teams managing such patients must be aware of the risk and be competent in detecting and managing any possible haematomas.

Pharmacokinetics of Direct Oral Anticoagulants in Emergency Situations: Results of the Prospective Observational RADOA-Registry

BACKGROUND

Direct oral anticoagulants (DOACs) are increasingly used worldwide. Little is known so far about their pharmacokinetics in emergency situations.

METHODS

A prospective, observational registry was performed to determine the clinical course in consecutive patients with major bleeding or urgent surgery treated with DOACs. In samples collected as part of routine care DOAC drug concentrations were measured using ultraperformance liquid chromatography-tandem mass spectrometry. Anticoagulant intensity at first presentation and drug half-life (t _1/2), tested in repeat samples, were evaluated.

RESULTS

A total of 140 patients were prospectively included. Pharmacokinetic data were available in 94% (132/140) of patients. Note that 67% (89/132) experienced life-threatening bleeding and 33% (43/132) needed an urgent surgery. For pharmacokinetic analysis a total of 605 blood samples was available. Median concentration on admission was 205 ng/mL for rivaroxaban and 108 ng/mL for apixaban. All treatment groups showed a high variation of drug concentrations at baseline. In rivaroxaban-treated patients t _½ was 17.3 hours (95% confidence interval [CI]: 15.4-19.7) without significant difference in both groups (major bleeding: t _½ 16.7 hours, 95% CI: 14.7-19.3; urgent surgery: t _½ 19.7 hours, 95% CI: 15.2-27.9; p = 0.292). In apixaban-treated patients t _½ was 25.0 hours (95% CI: 22.9-27.6) with a longer t _½ after urgent surgery (t _1/2: 30.8 hours; 95% CI: 26.9-36.4) compared with severe bleeding (t _1/2: 20.8 hours; 95% CI: 18.8-23.2; p < 0.001).

CONCLUSION

Emergency patients under DOAC treatment show a high variation of anticoagulant concentrations at baseline. Compared with rivaroxaban, apixaban showed a lower median concentration on admission and a longer t _½.

A meta-analysis of andexanet alfa and prothrombin complex concentrate in the treatment of factor Xa inhibitor-related major bleeding

Background

Andexanet alfa (andexanet) and prothrombin complex concentrate (PCC) are both reversal agents for major bleeding in patients using factor Xa inhibitors (FXaIs). Our aim was to evaluate the current evidence for the effectiveness and safety of andexanet and PCC in a systematic review and meta-analysis.

Objectives

Primary objective was hemostatic effectiveness. Secondary objectives were thromboembolic event rate and mortality.

Methods

A systematic review was performed in PubMed and Embase. Studies describing the effectiveness and/or safety of PCC or andexanet in patients with major bleeding using FXaIs were included. Meta-analysis was performed using a random-effects model.

Results

Seventeen PCC studies, 3 andexanet studies, and 1 study describing PCC and andexanet were included, comprising 1428 PCC-treated and 396 andexanet-treated patients. None of the included studies had control groups, hampering a pooled meta-analysis to compare the two reversal agents. Separate analyses for andexanet and PCC were performed. In subgroup analysis, the pooled proportion of patients with effective hemostasis in studies that used Annexa-4 criteria demonstrated a hemostatic effectiveness of 0.85 (95% confidence interval [CI], 0.80-0.90) in PCC and 0.82 (95% CI, 0.78-0.87) in andexanet studies. The pooled proportion of patients with thromboembolic events was 0.03 (95% CI, 0.02-0.04) in PCC and 0.11 (95% CI, 0.04-0.18) in andexanet studies.

Conclusion

Based on the available evidence with low certainty from observational studies, PCC and andexanet demonstrated a similar, effective hemostasis in the treatment of major bleeding in patients using FXaIs. Compared to PCC, the thromboembolic event rate appeared higher in andexanet-treated patients.

Direct Oral Anticoagulants Plasma Levels Measurement: Clinical Usefulness from Trials and Real-World Data

Measurement of direct oral anticoagulants (DOACs) activity is not routinely necessary. Indeed, evaluation of DOACs plasmatic concentration is discouraged for the majority of patients, due to the lack of outcome data supporting this approach. Nevertheless, DOAC measurements may be useful in emergency situations such as serious bleeding events, need for urgent invasive procedures, and acute ischemic stroke or in managing anticoagulation in "special populations" not adequately studied in clinical trials, for example the very elderly or those at the extremes of body weight. The aim of this review is to describe and summarize the methods for DOACs activity evaluation and the settings in which their plasma level measurement may be indicated, analyzing indications from scientific societies and evidence from clinical trials, as well as real world data on the usefulness of DOACs plasma levels "monitoring."

Severe Hemorrhage Associated With Oral Anticoagulants

BACKGROUND

Few data have been published to date on outcomes after the common clinical experience of severe hemorrhage in orally anticoagulated patients.

METHODS

A prospective, multicenter observational study was carried out to investigate outcomes and management in a series of consecutive patients who sustained a severe hemorrhage under treatment with vitamin K antagonists (VKA) or direct oral anticoagulant drugs (DOAC). The primary endpoint was in-hospital death up to and including day 30 after hospital admission. The secondary endpoints were the duration of bleeding, in-hospital death due to hemorrhage (as defined by the study physician examining the patient's records), the use of antagonists, the extent of supportive measures used to stop the hemorrhage, and an assessment of causality. Consecutive patients were recruited until a predefined number of patients was reached in both groups.

RESULTS

Among 193 patients with severe hemorrhage, 97 had been taking a VKA, and 96 had been taking a DOAC. 13.0 % (95% confidence interval [8.6; 18.5]; 25/193) of the overall group patients died in the first 30 days after hospital admission, including 17.5% ([10.6; 26.6]; 17/97) in the VKA group and 8.3% ([3.7; 15.8]; 8/96) in the DOAC group (p = 0.085). The median duration of bleeding was 19.8 hours in the VKA group and 27.8 hours in the DOAC group (p = 0.632). The in-hospital mortality due to hemorrhage was higher in the VKA group than in the DOAC group (15.5% [15/97] versus 4.2% [4/97]; p = 0.014). Only the use of prothrombin complex concentrates (PCCs) lowered the median duration of hemorrhage in the two patient groups. In 35% (68/193) of the patients, the hemorrhage was caused by an external influence, most commonly a fall.

CONCLUSION

The in-hospital mortality was higher among patients treated with VKA than among patients treated with DOAC, although the difference failed to reach statistical significance.

[Gastrointestinal Bleeding in Patients with Coronary Heart Disease: Preventive Options]

Extensive use of antithrombotic drugs (ATD) in patients with ischemic heart disease (IHD), on the one hand, provides a considerable decrease in the risk for development of life-threatening cardiovascular complications but on the other hand, is associated with a risk of gastrointestinal bleedings (GIB), which may develop in 0.5-1.0 % of patients. In such cases, the major measures for prevention of GIB are strict adherence to indications for the ATD treatment, detection and analysis of risk factors for GIB and their elimination as far as feasible. For evaluation of GIB risk in patients with IHD, the PRECISE-DAPT and DAPT, HAS-BLED scales should be used. If the risk factors are non-modifiable the therapeutic tactics for further management of these patients should be strictly individual with determining the nature of damage, degree of a risk for present and possible complications, and the range of required therapeutic and diagnostic measures. The use of ATD requires monitoring of the patient's condition to timely detect and treat GI complications.

An Update on the Reversal of Non-Vitamin K Antagonist Oral Anticoagulants

Non-vitamin K antagonist oral anticoagulants (NOACs) include thrombin inhibitor dabigatran and coagulation factor Xa inhibitors rivaroxaban, apixaban, edoxaban, and betrixaban. NOACs have several benefits over warfarin, including faster time to the achieve effect, rapid onset of action, fewer documented food and drug interactions, lack of need for routine INR monitoring, and improved patient satisfaction. Local hemostatic measures, supportive care, and withholding the next NOAC dose are usually sufficient to achieve hemostasis among patients presenting with minor bleeding. The administration of reversal agents should be considered in patients on NOAC's with major bleeding manifestations (life-threatening bleeding, or major uncontrolled bleeding), or those who require rapid anticoagulant reversal for an emergent surgical procedure. The Food and Drug Administration (FDA) has approved two reversal agents for NOACs: idarucizumab for dabigatran and andexanet alfa for apixaban and rivaroxaban. The American College of Cardiology (ACC), American Heart Association (AHA), and Heart Rhythm Society (HRS) have released an updated guideline for the management of patients with atrial fibrillation that provides indications for the use of these reversal agents. In addition, the final results of the ANNEXA-4 study that evaluated the efficacy and safety of andexanet alfa were recently published. Several agents are in different phases of clinical trials, and among them, ciraparantag has shown promising results. However, their higher cost and limited availability remains a concern. Here, we provide a brief review of the available reversal agents for NOACs (nonspecific and specific), recent updates on reversal strategies, lab parameters (including point-of-care tests), NOAC resumption, and agents in development.

Management of direct factor Xa inhibitor-related major bleeding with prothrombin complex concentrate: a meta-analysis

A targeted antidote for reversal of direct factor Xa (FXa) inhibitors is now available for clinical use in the United States, but it is costly and has limited availability. In a systematic review, we evaluated the safety and effectiveness of 4-factor prothrombin complex concentrate (4F-PCC) as an alternative for managing direct FXa inhibitor-related major bleeding. A systematic literature search was conducted using Medline, Embase, and the Cochrane Register of Controlled Trials up to September 2018. No comparative studies were found. Ten case series with 340 patients who received PCC for direct FXa inhibitor-related major bleeding were included. The pooled proportion of patients with effective management of major bleeding was 0.69 (95% confidence interval [CI], 0.61-0.76) in 2 studies using the International Society on Thrombosis and Haemostasis (ISTH) criteria and 0.77 (95% CI, 0.63-0.92) in 8 studies that did not use the ISTH criteria; all-cause mortality was 0.16 (95% CI, 0.07-0.26), and thromboembolism rate was 0.04 (95% CI, 0.01-0.08). On the basis of evidence with very low certainty from single-arm case series, it is difficult to determine whether 4F-PCC in addition to cessation of direct oral FXa inhibitor is more effective than cessation of direct oral FXa inhibitor alone in patients with direct FXa inhibitor-related major bleeding.

The 2018 European Heart Rhythm Association Practical Guide on the use of non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation

The current manuscript is the second update of the original Practical Guide, published in 2013 [Heidbuchel et al. European Heart Rhythm Association Practical Guide on the use of new oral anticoagulants in patients with non-valvular atrial fibrillation. Europace 2013;15:625-651; Heidbuchel et al. Updated European Heart Rhythm Association Practical Guide on the use of non-vitamin K antagonist anticoagulants in patients with non-valvular atrial fibrillation. Europace 2015;17:1467-1507]. Non-vitamin K antagonist oral anticoagulants (NOACs) are an alternative for vitamin K antagonists (VKAs) to prevent stroke in patients with atrial fibrillation (AF) and have emerged as the preferred choice, particularly in patients newly started on anticoagulation. Both physicians and patients are becoming more accustomed to the use of these drugs in clinical practice. However, many unresolved questions on how to optimally use these agents in specific clinical situations remain. The European Heart Rhythm Association (EHRA) set out to coordinate a unified way of informing physicians on the use of the different NOACs. A writing group identified 20 topics of concrete clinical scenarios for which practical answers were formulated, based on available evidence. The 20 topics are as follows i.e., (1) Eligibility for NOACs; (2) Practical start-up and follow-up scheme for patients on NOACs; (3) Ensuring adherence to prescribed oral anticoagulant intake; (4) Switching between anticoagulant regimens; (5) Pharmacokinetics and drug-drug interactions of NOACs; (6) NOACs in patients with chronic kidney or advanced liver disease; (7) How to measure the anticoagulant effect of NOACs; (8) NOAC plasma level measurement: rare indications, precautions, and potential pitfalls; (9) How to deal with dosing errors; (10) What to do if there is a (suspected) overdose without bleeding, or a clotting test is indicating a potential risk of bleeding; (11) Management of bleeding under NOAC therapy; (12) Patients undergoing a planned invasive procedure, surgery or ablation; (13) Patients requiring an urgent surgical intervention; (14) Patients with AF and coronary artery disease; (15) Avoiding confusion with NOAC dosing across indications; (16) Cardioversion in a NOAC-treated patient; (17) AF patients presenting with acute stroke while on NOACs; (18) NOACs in special situations; (19) Anticoagulation in AF patients with a malignancy; and (20) Optimizing dose adjustments of VKA. Additional information and downloads of the text and anticoagulation cards in different languages can be found on an EHRA website (www.NOACforAF.eu).

Four-factor Prothrombin Complex Concentrate for the Management of Patients Receiving Direct Oral Activated Factor X Inhibitors

Factor Xa inhibitors prevent thrombosis but are associated with severe or life-threatening bleeding. Here, the authors present data on four-factor prothrombin complex concentrates in management of anticoagulation-associated bleeding and restoring hemostasis, including recent results from the UPRATE study.

Prise en charge hémostatique des hémorragies cérébrales sous anticoagulants oraux

L’hématome intracrânien spontané a un pronostic clinique sévère. Le devenir des patients dépend de l’efficacité de la prise en charge initiale. L’importance du saignement, le volume de l’hématome et son évolution sont les facteurs principaux qui contrôlent mortalité et morbidité. Les traitements anticoagulants oraux, antivitamines K (AVK) et anticoagulants oraux directs (AOD), favorisent l’expansion de l’hématome. La correction rapide de l’hémostase permet le contrôle partiel de l’hématome. Alors que la réversion des AVK par les concentrés de complexe prothrombinique (CCP) a fait l’objet de recommandations bien diffusées, l’attitude thérapeutique reste peu codifiée avec les AOD, alliant l’utilisation de l’idarucizumab pour le dabigatran et des CCP pour les anti-Xa qui n’ont, pour l’instant, pas d’antidote.

Considerations when restarting anticoagulants in patients with atrial fibrillation after bleeding

Introduction: Oral anticoagulants (OACs) are established treatments to reduce thromboembolic risk in patients with atrial fibrillation (AF). Due to their mechanisms of action, they are associated with increased bleeding risk. Evaluation with bleeding risk scores may be useful to identify patients at high risk. However, the approach in patients who have suffered a recent bleeding event while on OACs is a contentious issue. If a decision is made to re-initiate OACs, the optimal timing for this remains controversial. Areas covered: Bleeding risk scores were designed to evaluate risk in patients with AF and indications for OACs. Some practical schemes were created to manage bleeding in this population. The types of bleeding were classified as minor, major non-life-threatening and major life-threatening bleeding. In AF patients suffering from severe acute bleeding, it is recommended to withhold OACs until the underlying cause is identified and treated. Each case will require an individualized decision to restarting OAC therapy after consideration of the risks, benefits, alternatives and patient's choice in the matter. Expert opinion: Management of major bleeding and restarting OACs in patients with a recent major bleeding poses a special challenge due to high bleeding and thrombotic risk. This will be discussed in this review.

Clinical and endoscopic features of severe acute gastrointestinal bleeding in elderly patients treated with direct oral anticoagulants: a multicentre study

BACKGROUND

The aim of the study was to describe the clinical and endoscopic characteristics and management of severe acute gastrointestinal (GI) bleeding in patients treated with direct oral anticoagulants (DOACs).

METHODS

Patients hospitalized for severe GI bleeding under DOAC therapy were identified in 36 centres between June 2013 and March 2016. Clinical outcomes including re-bleeding, major cerebral and cardiovascular events or all-cause mortality were assessed initially and 30 days after admission.

RESULTS

A total of 59 patients with anonymized detailed endoscopy reports for severe GI bleeding were considered. Mean age was 79.3 ± 10.0 years and 61.3% of patients were men. Patients had histories of hypertension (65.6%), heart failure (29.5%), coronary artery disease (27.9%), stroke (19.7%) and peripheral vascular disease (36.1%). Life-threatening bleeding was observed in 42.6%. Mean number of packed red blood cells transfused was 3.4 (range 1-31). Aetiology of bleeding (identified in 66.2% of cases) was peptic gastroduodenal ulcers (22%), diverticula (11.9%), angiodysplasia (8.5%), colorectal neoplasia (5.1%) and anorectal causes (5.1%). Endoscopic haemostasis was performed in 37.7% of patients. A low haemoglobin level was predictive of life-threatening bleeding and death in multivariate analysis. All-cause mortality rate at day 30 was 11.8%.

CONCLUSIONS

In this cohort of elderly patients with multiple comorbidities treated with DOACs, the main cause of severe acute GI bleeding was peptic gastroduodenal ulcer and mortality was high.

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

Background

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

Review

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

Conclusions

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

Electronic supplementary material

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

Rivaroxaban plasma levels in patients admitted for bleeding events: insights from a prospective study

Background

Serious bleeding events have been frequently described in patients taking direct oral anticoagulants (DOAC). In secondary analyses of phase 3 trials, DOAC plasma concentrations were shown to correlate with bleeding outcomes. This study aimed to describe rivaroxaban plasma levels in patients admitted to the emergency department (ED) for bleeding events. For each patient, risk factors for experiencing bleeding events were also investigated.

Methods

This analysis was part of an observational study conducted in the ED of two teaching hospitals. Plasma samples from 10 rivaroxaban-treated patients admitted for bleeding events were collected. Rivaroxaban plasma concentrations were determined by calibrated chromogenic anti-Xa assay. The measured rivaroxaban levels were then extrapolated at trough using a published population pharmacokinetic (PopPK) model, and compared to on-therapy ranges observed in large clinical trials. For each patient, clinical, medication and ABCB1 genotype data were collected.

Results

Rivaroxaban measurements varied from 5 to 358 ng/ml, with a post-intake delay ranging from 9 to 38 h. At trough, estimated plasma concentrations were between 12 and 251 ng/ml (median value 94 ng/ml). Four patients had higher-than-expected rivaroxaban levels. Inadequate dose regimen, excessive alcohol consumption and lack of treatment reassessment were observed in several patients. Half of patients were taking ≥1 drug with potential pharmacokinetics interactions (e.g. amiodarone, diltiazem), while half of patients were taking ≥1 drug increasing the risk of bleeding. All 3 patients with available genotyping data and higher-than-expected rivaroxaban levels were heterozygous or homozygous mutated for the ABCB1 1236C > T, 2677G > T, 3435 C > T and rs4148738 single nucleotide polymorphisms (SNP).

Conclusions

Rivaroxaban patients admitted to the ED for bleeding events showed highly variable plasma concentrations. This analysis underlines the usefulness of rapid DOAC measurement and the value of PopPK models to estimate concentrations at trough in a context where the post-intake delay is unmanageable. Close patient follow-up, including renal function assessment and drug interactions review, is essential for bleeding risk minimization.

Anti-Xa Oral Anticoagulant Plasma Concentration Assay in Real Life: Rivaroxaban and Apixaban Quantification in Emergency With LMWH Calibrator

BACKGROUND

Oral anti-Xa inhibitors have demonstrated noninferiority to vitamin K antagonists (VKAs) for the prevention of stroke in patients with atrial fibrillation and recurrent venous thromboembolism. They are associated with a decrease in major bleeding. In contrast with VKA, no coagulation monitoring is required. However, in clinical practice, determination of drug concentration is sometimes necessary.

OBJECTIVE

The objective of this study was to evaluate a low-molecular-weight heparin (LMWH) calibrated anti-Xa assay for the quantification of rivaroxaban and apixaban plasma concentration in emergency.

METHODS

The anti-Xa plasma concentration of rivaroxaban and apixaban were measured in emergency in 210 patients using STA anti-Xa liquid assay. For each plasma concentration <150 ng/mL of rivaroxaban or apixaban, an anti-Xa assay calibrated with LMWH was performed.

RESULTS

We demonstrated a significant correlation between LMWH anti-Xa activity and rivaroxaban ( R² = 0.947) or apixaban ( R² = 0.959) concentration and a significant correlation between rivaroxaban and apixaban plasma concentration ( R² = 0.972). A LMWH anti-Xa activity <0.50 IU/mL could exclude a plasma concentration of rivaroxaban and apixaban >30 ng/mL and indicate the feasibility of invasive procedure. Conclusion and Relevance: In the absence of a specific test, LMWH-calibrated anti-Xa assay could be used to determine the presence and evaluate the plasma concentration of oral anti-Xa inhibitors. However, these initial findings require confirmation using other chromogenic calibrated oral anti-Xa assays.

The Reversal of Bleeding Caused by New Oral Anticoagulants (NOACs): A Systematic Review and Meta-Analysis

New oral anticoagulants (NOACs; ie, direct thrombin inhibitor [DTI] and factor Xa [FXa] inhibitors) were used as alternatives to warfarin. Specific antidotes (idarucizumab for dabigatran and andexanet alfa for FXa inhibitors) and hemostatic reversal agents were used for lowering bleeding, but their efficacies were still uncertain. The objectives of this study were to estimate and compare the efficacy of NOAC antidotes on bleeding reversal and death. Studies were identified from MEDLINE and Scopus databases until May 2018. Case reports/series and cohorts were selected if they assessed reversal or death rates. Data were independently extracted by 2 reviewers. Individual patient data and aggregated data of outcomes were extracted from case reports/series and cohorts. Binary regression was used to estimate outcome rates, risk ratio (RR) along with 95% confidence interval (CI). Interventions were NOACs and reversal agents (ie, DTI-specific, DTI-standard, FXa-specific, and FXa-standard). Among 220 patients of 93 case reports/series, reversal rates were 95.9%, 77.6%, and 71.5% for DTI-specific, FXa-standard, and DTI-standard. Pooled RRs for DTI-specific and FXa-standard versus DTI-standard, respectively, were 1.34 (CI: 1.13-1.60) and 1.09 (CI: 0.84-1.40). Death rate was 0.18 (CI: 0.06-0.57) times lower in DTI-specific versus DTI-standard. For pooling 10 subcohorts, pooled RRs were 1.08 (CI: 1.00-1.16), 1.29 (CI: 1.20-1.39), and 1.13 (CI: 1.01-1.25) for DTI-specific, FXa-specific, and FXa-standard versus DTI-standard. In conclusion, specific reversal agents might be useful for reversal of bleeding and lowering the risk of death than standard reversal agents. Our findings were based on case reports/series and selected cohorts, further comparative studies are thus needed.

The reversal of anticoagulation in clinical practice

Widespread use of anticoagulant drugs for treatment and -prevention of thromboembolic events means it is common to encounter patients requiring reversal of anticoagulation for management of bleeding or invasive procedures. While supportive and general measures apply for patients on all agents, recent diversification in the number of licensed agents makes an understanding of drug-specific reversal strategies essential. Recognising effects upon, and limitations of, laboratory measures of coagulation also plays an important role. An understanding of reversal strategies alone is insufficient to competently care for patients who may require anticoagulation reversal. It is also necessary to reduce the need for reversal through correct prescribing and by employing appropriate periprocedural bridging strategies for elective and semi-elective procedures. Finally, consideration of whether and when to reintroduce an anticoagulant drug following reversal is important not only to balance bleeding and thrombotic risks for individual patients but also for timely management of discharge.

Oral anti-Xa anticoagulation after trans-aortic valve implantation for aortic stenosis: The randomized ATLANTIS trial

BACKGROUND

Antithrombotic treatment regimen following transcatheter aortic valve replacement (TAVR) is not evidence-based. Apixaban, a non-vitamin K direct anticoagulant (NOAC) was shown to be superior to VKA and superior to aspirin to prevent cardioembolic stroke in non-valvular atrial fibrillation. It may have the potential to reduce TAVR-related thrombotic complications including subclinical valve thrombosis along with a better safety than the standard of care.

DESIGN

ATLANTIS is a multicenter, randomized, phase IIIb, prospective, open-label, superiority study comparing standard of care (SOC Group) versus an apixaban-based strategy (Anti-Xa Group) after successful TAVR (ClinicalTrials.gov NCT 02664649). Randomization is stratified according to the need for chronic anticoagulation therapy for a reason other than the TAVR procedure. In the experimental arm, patients receive 5 mg bid of apixaban or a reduced dose of 2.5 mg bid according to the drug label or when apixaban is combined with antiplatelet therapy. In the control arm, patients receive VKA therapy if there is an indication for oral anticoagulation or antiplatelet therapy alone (single or dual) or the combination of both if needed. The primary study end point is the composite of all-cause death, TIA/stroke, myocardial infarction, symptomatic valve thrombosis, pulmonary embolism, deep venous thrombosis, systemic embolism, life-threatening, disabling or major bleeding, according to the Valve Academic Research Consortium definitions.

CONCLUSIONS

ATLANTIS tests the superiority of an apixaban-based strategy versus the recommended standard of care strategy to reduce the risk of post-TAVR thromboembolic and bleeding complications in an all comer population.

[Direct oral anticoagulants (DOACS): A necessary focus]

In 2008, we decided to enter the era of direct oral anticoagulants (DOACS). Was that the right decision to make? The answer will depend on how well we meet the conditions of proper use. This means avoiding underdosing and overdosing as well as understanding how DOACS were validated so that our prescriptions fulfill their role in the management of thrombotic disease.

The anticoagulant effect of therapeutic levels of dabigatran in atrial fibrillation evaluated by thrombelastography (TEG®), Hemoclot Thrombin Inhibitor (HTI) assay and Ecarin Clotting Time (ECT)

Monitoring the effect of dabigatran (Pradaxa^®) is challenging. The aim of this study was to evaluate if thrombelastography reaction time (TEG^® R) could detect the anticoagulant effect of dabigatran showing a correlation between TEG^® R, Hemoclot Thrombin Inhibitor (HTI) assay and Ecarin Clotting Time (ECT) in patients with non-valvular atrial fibrillation (NVAF). Blood samples from 35 AF patients receiving either 110 mg (n 19) or 150 mg (n 16) dabigatran twice daily were analyzed with TEG^®, HTI and ECT 2-3 h after dabigatran intake. All patients had prolonged TEG^® R. The patients receiving dabigatran 110 mg ×2 had a TEG^® R mean 14.2 min (range 9.1-25), a mean dabigatran concentration measured by HTI of 268.5 ng/mL (range 54-837 ng/mL) and by ECT of 355.7 ng/mL (range 40-1020 ng/mL). The corresponding numbers for patients receiving dabigatran 150 mg ×2 were TEG^® R mean of 12.5 min (range 9.2-23.2 min), mean dabigatran concentration of 179.2 ng/mL by HTI (range 26-687 ng/mL) and by ECT 225.1 ng/mL (range 42-1020 ng/mL). The two dosage groups had comparable anticoagulation demonstrated by equally prolonged TEG^® R (p = .909), HTI (p = .707) and ECT (p = .567). No difference in creatinine levels in the two dosage groups was observed (p = .204) though patients with dabigatran concentration >400 ng/mL had significantly higher creatinine levels (p = .001). Large individual variation of the anticoagulant response was observed. Some patients had TEG^® R values up to three times upper normal limit with immediate risk of bleeding. Our data indicate that TEG^® R reflected dabigatran levels in NVAF patients and that TEG^® R correlated to HTI and ECT.