Effect of low- versus high-dose 4-factor prothrombin complex concentrate in factor Xa inhibitor-associated bleeding: A qualitative systematic review

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PURPOSE

The purpose of this review is to evaluate current literature on the treatment of factor Xa inhibitor-associated bleeds with 4-factor prothrombin complex concentrate (4F-PCC), with a focus on the effect of low versus high dosing of 4F-PCC on hemostatic efficacy and safety outcomes.

SUMMARY

A search of PubMed and EBSCOhost was performed to identify studies evaluating patients with a factor Xa inhibitor-bleed treated with 4F-PCC at either low or high doses. Studies of patients receiving alternative reversal agents such as fresh frozen plasma and andexanet alfa or where no comparator group was evaluated were excluded from the analysis. To assess the effect of these 4F-PCC dosing strategies, the primary outcome of interest was hemostatic efficacy. Four studies meeting inclusion criteria were included in this review. In each of the included studies, similar rates of hemostatic efficacy, hospital mortality, and venous thromboembolism were observed in the low- and high-dose cohorts.

CONCLUSION

These results suggest low- and high-dose 4F-PPC may confer similar clinical effectiveness and safety; however, these findings should be evaluated and confirmed with future prospective studies.

Hemostatic Efficacy and Safety of Weight-Based Versus Fixed-Dose 4F-PCC for Vitamin K Antagonist Reversal

Background: Four-factor prothrombin complex concentrate (4F-PCC) is indicated for vitamin K antagonist (VKA) reversal but is associated with thrombotic events (TE). In 2018, the institution revised 4F-PCC dosing for VKA reversal from INR and weight-based dosing to a fixed-dose of 1500 units. Objective: The purpose of this study was to compare hemostatic efficacy and TE rate of fixed-dose 4PCC to weight-based dosing. Methods: This was a retrospective, single-center, quasi-experimental study of adult patients who received 4F-PCC for VKA reversal from January 2014 through May 2016 (INR and weight-based dosing) or April through October 2018 (fixed-dosing). The primary endpoint was hemostatic efficacy, defined by achieving an INR of ≤1.4, or an INR of ≤1.7 with evidence of hemostasis. The key secondary endpoint was TE within 14 days of 4F-PCC administration. Data were analyzed using descriptive statistics, chi-squared for nominal data and Mann-Whitney U for ordinal and continuous data. Results: The study included 163 patients who received weight-based dosing and 45 who received fixed-dose 4F-PCC. Hemostatic efficacy was 76.9% of patients in the weight-based group and 77.4% of patients in the fixed-dose group (P = .229). TE occurred in 13.5% of the weight-based vs 6.7% of the fixed-dose group (P = .181). Conclusion: This study found no difference in hemostatic efficacy with fixed-dose 4F-PCC for VKA reversal compared to INR and weight-based dosing. The occurrence of TE was reduced by 50% with the 4F-PCC fixed-dose strategy; however, this difference was not statistically significant. Further randomized studies are needed to confirm these results.

Effects of Mobile Stroke Unit dispatch on blood pressure management and outcomes in patients with intracerebral haematoma: Results from the Berlin_Prehospital Or Usual Care Delivery in acute Stroke (B_PROUD) controlled intervention study

INTRODUCTION

In patients with acute intracerebral haemorrhage (ICH) and elevated systolic blood pressure (BP), guidelines suggest that systolic BP reduction to <140 mmHg should be rapidly initiated. Compared with conventional care, Mobile Stroke Units (MSUs) allow for earlier ICH diagnosis through prehospital imaging and earlier BP lowering.

PATIENTS AND METHODS

ICH patients were prospectively evaluated as a cohort of the controlled B_PROUD-study in which MSU availability alone determined MSU dispatch in addition to conventional ambulance. We used inverse probability of treatment weighting to adjust for confounding to estimate the effect of additional MSU dispatch in ICH patients. Outcomes of interest were 7-day mortality (primary), systolic BP (sBP) at hospital arrival, dispatch-to-imaging time, largest haematoma volume, anticoagulation reversal, length of in-hospital stay, 3-month functional outcome.

RESULTS

Between February 2017 and May 2019, MSUs were dispatched to 95 (mean age: 72 ± 13 years, 45% female) and only conventional ambulances to 78 ICH patients (mean age: 71 ± 12 years, 44% female). After adjusting for confounding, we found shorter dispatch-to-imaging time (mean difference: -17.75 min, 95% CI: -27.16 to -8.21 min) and lower sBP at hospital arrival (mean difference = -16.31 mmHg, 95% CI: -30.64 to -6.19 mmHg) in the MSU group. We found no statistically significant difference for the other outcomes, including 7-day mortality (adjusted odds ratio: 1.43, 95% CI: 0.68 to 3.31) or favourable outcome (adjusted odds ratio = 0.67, 95% CI: 0.27 to 1.67).

CONCLUSIONS

Although MSU dispatch led to sBP reduction and lower dispatch-to-imaging time compared to conventional ambulance care, we found no evidence of better outcomes in the MSU dispatch group.

Effect of PCC on Thrombin Generation among Patients on Factor Xa Inhibitors with Major Bleeding or Needing Urgent Surgery (GAUGE): Design and Rationale

Background  Direct factor Xa inhibitors (FXaIs) account for most oral anticoagulant use and FXaI-associated bleeding events are common. Clinicians have variable national and regional access to specific FXaI reversal agents such as andexanet alfa. Many centers have adopted the use of prothrombin complex concentrates (PCCs) as hemostatic therapy for FXaI-associated major bleeding events. PCC does not impact circulating FXaI levels and its mechanism of action to achieve hemostasis in FXaI-associated bleeding is uncertain. While PCC increases quantitative thrombin generation assay (TGA) parameters, it does not correct FXaI-altered thrombin generation kinetics, nor does it normalize thrombin generation. Clinical data supporting the use of PCC are based on cohort studies reporting clinical hemostatic efficacy, which is difficult to measure. The benefits of PCC for FXaI-associated bleeding beyond supportive care are uncertain. Objective  GAUGE is a prospective observational study designed to measure the effects of four-factor PCC administration (Octaplex) on TGA parameters among patients with FXaI-associated bleeding or needing urgent surgery. Methods  Laboratory outcomes will include the mean paired change in TGA parameters from pre- to post-PCC administration and the proportion of participants whose post-PCC TGA values fall within a defined reference range. Clinical outcomes will include hemostatic efficacy, thromboembolic complications, and all-cause death at 30 days post-PCC. Conclusion  Development of a viable and universally accessible FXaI bleed management strategy is crucial. GAUGE will provide in vivo data on the effects of PCC among patients with FXaI-associated bleeding.

What's fishy about protamine? Clinical use, adverse reactions, and potential alternatives

Protamine, a highly basic protein isolated from salmon sperm, is the only clinically available agent to reverse the anticoagulation of unfractionated heparin. Following intravenous administration, protamine binds to heparin in a nonspecific electrostatic interaction to reverse its anticoagulant effects. In clinical use, protamine is routinely administered to reverse high-dose heparin anticoagulation in cardiovascular procedures, including cardiac surgery with cardiopulmonary bypass. Despite the lack of supportive evidence regarding protamine's effectiveness to reverse low-molecular-weight heparin, it is recommended in guidelines with low-quality evidence. Different dosing strategies have been reported for reversing heparin in cardiac surgical patients based on empiric dosing, pharmacokinetics, or point-of-care measurements of heparin levels. Protamine administration is associated with a spectrum of adverse reactions that range from vasodilation to life-threatening cardiopulmonary dysfunction and shock. The life-threatening responses appear to be hypersensitivity reactions due to immunoglobulin E and/or immunoglobulin G antibodies. However, protamine and heparin-protamine complexes can activate complement inflammatory pathways and inhibit other coagulation factors. Although alternative agents for reversing heparin are not currently available for clinical use, additional research continues evaluating novel therapeutic approaches.

DOAC-associated bleeding, hemostatic strategies, and thrombin generation assays - a review of the literature

Direct oral anticoagulants (DOACs) account for most oral anticoagulant use. DOAC-associated bleeding events are commonly encountered in clinical practice and are associated with substantial morbidity and mortality. Both specific reversal agents and nonspecific hemostatic therapies, such as prothrombin complex concentrates, are used in the management of DOAC-associated bleeding. Measuring hemostatic efficacy and demonstrating a clinical impact from these therapies among studies of bleeding patients is challenging. Thrombin generation assays provide information on the total hemostatic potential of plasma, and have emerged as a promising modality to both measure the impact of DOACs on coagulation and to evaluate the effects of hemostatic therapies among patients with DOAC-associated bleeding. The mechanisms by which nonspecific hemostatic agents impact coagulation and thrombin generation in the context of DOAC therapy are unclear. As a result, we undertook a review of the literature using a systematic search strategy with the goal of summarizing the effects of DOACs on thrombin generation and the effects of both specific reversal agents and nonspecific hemostatic therapies on DOAC-altered thrombin generation parameters. We sought to identify clinical studies focusing on whether altered thrombin generation is associated with clinical bleeding and whether correction of altered thrombin generation parameters predicts improvements in clinical hemostasis. Lastly, we sought to outline future directions for the application of thrombin generation assays toward anticoagulation therapies and the question of anticoagulation reversal.

Retrospective Analysis of the Real-World Utilization of 4-Factor Prothrombin Complex Concentrate and Plasma in Oral Anticoagulant-Associated Bleeding in US Hospitals

Real-world utilization of 4-factor prothrombin complex concentrate (4F-PCC) and plasma for the management of oral anticoagulant (OAC)-associated bleeding in US trauma hospitals was described.This is amulticenter, retrospective chart review evaluating the use of 4F-PCC and plasma in OAC reversal across medical specialties. Physicians completed a survey and extracted data from 3 to 5 patient charts. Variables of interest included medical specialty, urgency, and bleed type. Two hundred and thirty-five physicians completed the survey, and 861 patient charts were included in the study. 4F-PCC was commonly used in life-threatening or emergent indications, whereas plasma was used in emergent and urgent indications. Plasma was used mostly for patients on warfarin (53% vs 47% 4F-PCC) and 4F-PCC for those on apixaban (82% vs 18% plasma) and rivaroxaban (77% vs 23% plasma). This retrospective analysis showed that 4F-PCC was predominantly used for OAC reversal despite available specific reversal agents for some of the OAC. Although it is not recommended by any reversal guidelines, plasma is still used for OAC reversal. Plasma should be avoided in the management of OAC-associated bleeding.

Supratherapeutic dabigatran: a cause of life-threatening haemorrhage

In this case report, we present a rare case of life-threatening gastrointestinal haemorrhage associated with deranged coagulation due to supratherapeutic levels of dabigatran. Dabigatran is a potent, synthetic, reversible non-peptide thrombin inhibitor which is increasingly used for stroke prevention in patients with non-valvular atrial fibrillation. It is generally accepted that dabigatran dosing does not require titration or the monitoring of plasma levels due to its predictable pharmacokinetics and pharmacodynamics. However, this case report challenges this viewpoint while identifying an important knowledge gap in relation to the effect of altered gastrointestinal motility on the absorption of direct oral anticoagulants. Furthermore, it demonstrates the successful use of high-dose idarucizumab in a critical care setting. Idarucizumab is a monoclonal antibody fragment that binds specifically to dabigatran and its metabolites, thereby reversing the anticoagulant effect.

The Role of Thromboelastography in Identifying Coagulopathy Among Geriatric Traumatic Brain Injury Patients

Background The geriatric population has the highest incidence of head injury, and those who are anticoagulated have an increased risk of traumatic intracranial hemorrhage (ICH). The availability of viscoelastic coagulation studies has coincided with the development of many anticoagulation reversal agents. In this study, our objective was to assess whether the thromboelastography (TEG) assay affected clinical decision-making regarding reversal agent administration among geriatric patients with ICH caused by blunt head trauma. Methodology We prospectively screened adults aged 65 and older with head trauma presenting to the emergency departments of two level-one trauma centers. International Classification of Diseases, Tenth Revision codes S00-09 were used to identify the diagnosis of head injury. Patients with CT head imaging positive for acute ICH were included. Each patient was assessed for home use of antiplatelet or anticoagulant medications, as well as in-hospital use of any reversal agents. Reversal agent administration and mortality were compared between patients who received TEG and those who did not. Results A total of 680 patients had acute ICH on head CT, and 324 (48%) patients received TEG. More patients screened with TEG were transfused platelets (30.2% vs. 10.7%, p < 0.001). This remained significant for patients taking anticoagulants, antiplatelets, or neither. There were no differences in the administration of other reversal agents (prothrombin complex concentrate or fresh frozen plasma) or mortality whether or not TEG was performed. Conclusions Patients who had TEG performed were more likely to receive platelet reversal agents, regardless of antiplatelet medication usage. Among elderly adults with ICH, TEG is a rapid screening test that may help identify patients with platelet function abnormalities requiring reversal.

Reversal of apixaban and rivaroxaban with andexanet alfa prior to invasive or surgical procedures

BACKGROUND

Outcomes following andexanet alfa reversal of factor Xa inhibitors in patients requiring urgent or emergent invasive procedures are lacking. This study aimed to describe efficacy and safety outcomes following andexanet alfa administration within 24 h of an invasive procedure.

METHODS

This single-center, observational, retrospective study included patients who received andexanet alfa within 24 h of an invasive or surgical procedure. The primary outcome was hemostatic efficacy graded as excellent, good, or poor using similar definitions to the ANNEXA-4 criteria. Secondary outcomes included hospital discharge disposition, intensive care unit (ICU) and hospital length of stay, 30-day mortality, 30-day thromboischemic event rates, and serum coagulation assay changes pre- and postreversal.

RESULTS

Forty-four patients met inclusion criteria; of these, 27 (62.8%) received apixaban and 16 (37.2%) were treated with rivaroxaban prior to admission. The indications for reversal were categorized as intracranial (n = 20 [45.5%]) or extracranial (n = 24 [54.5%]) sites. Majority of patients required emergent operative procedures (18 [40.9%]), followed by invasive device placement (10 [22.7%]) or arterial embolization (9 [20.5%]). Thirty-eight (86.4%) patients were able to be adequately graded for hemostatic efficacy. Overall, 30 (78.9%) patients achieved excellent or good hemostasis within 24 h after periprocedural administration of andexanet alfa (19 [82.6%] apixaban vs. 11 [78.6%] rivaroxaban; 12 [80.0%] intracranial events vs. 18 [78.3%] extracranial events). Discharge disposition was most often to a short- or long-term care facilities (27 [61.4%]). Thirty-day mortality and thromboischemic complications occurred in 15 (34.1%) and 12 (27.3%) patients, respectively. Prothrombin time and antifactor Xa assay results were significantly decreased after andexanet alfa administration (p < 0.05) while thromboelastogram assay values (reaction time, kinetic time, and activated clotting time) showed nonsignificant changes pre- versus postreversal.

CONCLUSION

Andexanet alfa may be used for urgent or emergent reversal of apixaban and rivaroxaban peri-procedurally with promising hemostatic outcomes. Further prospective, comparative clinical research is warranted.

Extended Anticoagulation after Radical Cystectomy Using Direct Acting Oral Anticoagulants: A Single-Institutional Experience

INTRODUCTION

Extended prophylactic anticoagulation therapy with enoxaparin 40 mg daily is effective in reducing the incidence of venous thromboembolism (VTE) after radical cystectomy. In an effort to improve compliance, we modified our extended anticoagulation options to direct oral anticoagulants (DOAs; eg apixaban 2.5 mg twice daily or rivaroxaban 10 mg daily). This study assesses our experience with extended VTE prophylaxis using DOAs.

METHODS

This is a retrospective review that included all patients who underwent radical cystectomy at our institution between January 2007 and June 2021. Multivariable logistic regression models were constructed to test the hypothesis that use of extended DOAs is similar to enoxaparin in terms of VTE events and risk of gastrointestinal bleeding.

RESULTS

In 657 patients, the median age was 71 years. Of the 101 patients who received extended VTE prophylaxis, 46 (45.5%) patients received rivaroxaban/apixaban. At 90 days of followup, 40 patients (7.2%) who did not receive extended prophylaxis on discharge developed a VTE compared to 2 patients (3.6%) in the enoxaparin group and 0 patients in the DOA group (p=0.11). Seven patients (1.3%) who did not receive extended anticoagulation developed gastrointestinal bleeding compared to 0 patients in the enoxaparin group and 1 (2.2%) in the DOA group (p=0.60). On multivariable analysis, both enoxaparin and DOAs were associated with similar reductions in the risk of developing VTE compared to controls (enoxaparin: OR 0.33, p=0.09 and DOAs: OR 0.19, p=0.15).

CONCLUSIONS

These preliminary data suggest that oral apixaban and rivaroxaban are acceptable alternatives to enoxaparin with similar safety and efficacy profiles.

In vitro reversal of direct factor Xa inhibitors: Direct comparison of andexanet alfa and prothrombin complex concentrates Cofact and Beriplex/Kcentra

Background

Both andexanet alfa and four‐factor prothrombin complex concentrate (4F‐PCC) are clinically applied reversal agents for direct factor Xa inhibitors (FXaIs) in emergency situations. Controversy exists whether 4F‐PCC is as effective as andexanet alfa in correcting FXaI anticoagulation.

Objective

This in vitro study was designed to directly compare andexanet alfa with two different 4F‐PCCs (Cofact and Beriplex/Kcentra) in their ability to correct FXaI anticoagulation.

Method

Normal plasma was spiked with apixaban or rivaroxaban. Reversal of anticoagulation was assessed using a thrombin generation assay and a fibrin generation–clot lysis test.

Results

Andexanet alfa, applied at clinically recommended doses, was effective in restoring thrombin generation as evidenced by correction of thrombin generation lag time, peak thrombin, and endogenous thrombin potential (ETP). Clotting time and clot resistance to fibrinolytic breakdown was corrected over the full range of applied FXaI (0–800 ng/ml). 4F‐PCC in increasing doses (0.625, 1.25 and 2 IU/ml; approximately 25, 50, and 80 IU/kg) only partially restored thrombin generation lag time and clotting time. Partial correction to overnormalization of peak thrombin and ETP was observed, depending on FXaI concentration and PCC dose. Clot resistance to fibrinolytic breakdown was dose‐dependently improved to above normal. Beriplex/Kcentra was consistently less effective than Cofact.

Conclusion

Both andexanet alfa and 4F‐PCC improved coagulation that is hampered by FXaIs. While andexanet alfa corrected all thrombin generation parameters, 4F‐PCC predominantly increased peak thrombin and ETP. Especially heparin‐free 4F‐PCC also improved clot stability against fibrinolytic breakdown. Beriplex/Kcentra contains heparin, and this may have caused reduced effectivity compared to Cofact.

Warfarin-induced skin necrosis after the use of an anticoagulation reversal agent

Anticoagulant-induced skin necrosis is a rare and potentially life-threatening complication of anticoagulant therapy. The majority of cases of anticoagulant-induced skin necrosis have been attributed to warfarin, known as warfarin-induced skin necrosis (WISN). The use of anticoagulation reversal agents such as Prothrombinex-VF in the development of WISN is not a commonly documented phenomenon. The authors present a case of WISN post-recommencement of warfarin and the use of Prothrombinex-VF.

Management of Coagulopathy in Bleeding Patients

Early recognition of coagulopathy is necessary for its prompt correction and successful management. Novel approaches, such as point-of-care testing (POC) and administration of coagulation factor concentrates (CFCs), aim to tailor the haemostatic therapy to each patient and thus reduce the risks of over- or under-transfusion. CFCs are an effective alternative to ratio-based transfusion therapies for the correction of different types of coagulopathies. In case of major bleeding or urgent surgery in patients treated with vitamin K antagonist anticoagulants, prothrombin complex concentrate (PCC) can effectively reverse the effects of the anticoagulant drug. Evidence for PCC effectiveness in the treatment of direct oral anticoagulants-associated bleeding is also increasing and PCC is recommended in guidelines as an alternative to specific reversal agents. In trauma-induced coagulopathy, fibrinogen concentrate is the preferred first-line treatment for hypofibrinogenaemia. Goal-directed coagulation management algorithms based on POC results provide guidance on how to adjust the treatment to the needs of the patient. When POC is not available, concentrate-based management can be guided by other parameters, such as blood gas analysis, thus providing an important alternative. Overall, tailored haemostatic therapies offer a more targeted approach to increase the concentration of coagulation factors in bleeding patients than traditional transfusion protocols.

Thromboembolic Complications After Receipt of Prothrombin Complex Concentrate

Purpose: Patients presenting with life-threatening bleeding associated with oral anticoagulants (OACs) are challenging with few available treatments. Prothrombin complex concentrate (PCC) is an option for OAC reversal in the setting of life-threatening bleeding with a relatively benign safety profile. Little is known about the risk of developing thromboembolic complications (TEC) in patients receiving PCC who were previously anticoagulated. The aim of this study is to characterize the rate of TEC after receipt of PCC. Methods: All adult patients who received 4-Factor PCC for life-threatening bleeding were retrospectively evaluated over a 2-year time period. Data collected included anticoagulant and indication, bleeding source, PCC dose, INR, and TEC within 14 days of PCC dose, including venous thromboembolism (VTE), acute myocardial infarction, and ischemic stroke. Results: Three hundred thirty-three patients received 383 PCC doses. Of these, 55 (16.5%) patients developed TEC, including VTE, ischemic stroke, and acute myocardial infarction. There was increased rivaroxaban use in patients who developed TEC (25.4% vs 12.2%; P = .011). Additionally, there were more patients who had anticoagulation for a previous TEC in those who developed a new TEC (38.2% vs 23.4%; P = .022). Lastly, there was a higher rate of TEC in those who received >1 dose of PCC (21.8% vs 7.9%; P = .002). Conclusion: PCC administration in the setting of life-threatening bleeding is not benign. Risk of TEC increases in patients who have rivaroxaban reversal, receive a repeat dose of PCC, and have a TEC indication for their anticoagulation and these factors should be further investigated.

Utilization of anti-factor Xa levels to guide reversal of oral factor Xa inhibitors in the emergency department

Purpose

Oral factor Xa inhibitors (FXaIs) are increasingly utilized for outpatient anticoagulation therapy; however, laboratory monitoring is not routinely used to assess the safety and efficacy of these agents. We aimed to evaluate the role of chromogenic anti–factor Xa (anti-Xa) assays in the emergency department (ED) in the setting of patients with an acute bleed or requiring emergent procedures.

Methods

A retrospective review of anti-Xa levels obtained in the ED between June 1, 2019, and April 30, 2020, was completed. Data were collected to describe the clinical setting of anti-Xa level collection, oral FXaIs used before admission, administration of reversal agents, and patient disposition to further characterize the role of anti-Xa levels in the management of rivaroxaban and apixaban reversal.

Results

Thirty anti-Xa levels were included in the final analysis. The median time from sample collection to anti-Xa assay result was 45.9 minutes (interquartile range, 35.3-54.7 minutes). Eleven patients (37%) received anticoagulation reversal after their anti-Xa levels were determined. Anticoagulation reversal agents included either activated prothrombin complex concentrates (aPCCs) or prothrombin complex concentrates (PCCs). Anti-Xa levels were collected in 2 patients who had received PCCs before arrival at our ED. Of the patients with anti-Xa levels below 30 ng/mL, none received aPCCs or PCCs after their anti-Xa levels were determined. Anti-Xa assays were used to rule out the presence of FXaIs in 3 patients.

Conclusion

This study illustrates the novel role of anti-Xa levels in managing patients with an emergent need for reversal in the ED. The assay may be used to rule out the presence of oral FXaIs and avoid unnecessary administrations of anticoagulation reversal agents.

Comparison of Low- Versus High-Dose Four-Factor Prothrombin Complex Concentrate (4F-PCC) for Factor Xa Inhibitor-Associated Bleeding: A Retrospective Study

BACKGROUND

Although andexanet alfa was recently approved as a specific reversal agent for apixaban and rivaroxaban, some providers still elect to administer 4-factor prothrombin complex concentrate (4F-PCC) instead, due to concerns surrounding efficacy, thrombotic risk, administration logistics, availability, and cost. Previous studies have described success with 4F-PCC doses ranging from 25 to 35 U/kg, with some guidelines recommending 50 U/kg.

OBJECTIVES

The purpose of this study was to compare hemostasis between patients receiving low- (20-34 U/kg) versus high-dose (35-50 U/kg) 4F-PCC for the urgent reversal of apixaban and rivaroxaban.

PATIENTS/METHODS

We performed a retrospective cohort study at a level one trauma center and comprehensive stroke center between January 2015 and December 2018. Main exclusion criteria included patients receiving less than 20 U/kg or if postreversal imaging were unavailable. Outcomes assessed included hemostasis for critical bleeding associated with apixaban or rivaroxaban and postoperative bleeding for reversal for emergent procedures.

RESULTS

The low-dose strategy was administered to n = 57 (57.6%) patients at a mean dose of 26.6 U/kg. The high-dose strategy was used in n = 42 (42.4%) patients at a mean dose of 47.6 U/kg. There was no difference in hemostasis by dosing strategy (75.4% vs 78.6%, P = .715) or hospital mortality (19.3% vs 35.7%, P = .067). No difference was found for secondary end points, including thrombotic events (5.3% vs 2.4%, P = .635) and hospital length of stay (11.3 vs 12.5 days, P = .070).

CONCLUSIONS

Our comparison addresses a gap in the literature surrounding optimal dosing and supports a similar efficacy profile between dosing low- versus high-dose treatment.

Limitations of Specific Coagulation Tests for Direct Oral Anticoagulants: A Critical Analysis

Background

During treatment with direct oral anticoagulants (DOAC), coagulation assessment is required before thrombolysis, surgery, and if anticoagulation reversal is evaluated. Limited data support the accuracy of DOAC‐specific coagulation assays around the current safe‐for‐treatment threshold of 30 ng/mL.

Methods and Results

In 481 samples obtained from 96 patients enrolled at a single center, DOAC concentrations were measured using Hemoclot direct thrombin inhibitor assay, Biophen direct thrombin inhibitor assay or ecarin clotting time for dabigatran, chromogenic anti‐Xa assay (AXA) for factor Xa inhibitors (rivaroxaban, apixaban) and ultraperformance liquid chromatography–tandem mass spectrometry as reference. All dabigatran‐specific assays had high sensitivity to concentrations >30 ng/mL, but specificity was lower for Hemoclot direct thrombin inhibitor assay (78.2%) than for Biophen direct thrombin inhibitor assay (98.9%) and ecarin clotting time (94.6%). AXA provided high sensitivity and specificity for rivaroxaban, but low sensitivity for apixaban (73.8%; concentrations up to 82 ng/mL were misclassified as <30 ng/mL). If no DOAC‐specific calibration for AXA is available, results 2‐fold above the upper limit of normal indicate relevant rivaroxaban concentrations. For apixaban, all elevated results should raise suspicion of relevant anticoagulation.

Conclusions

DOAC‐specific tests differ considerably in diagnostic performance for concentrations close to the currently accepted safe‐for‐treatment threshold. Compared with Biophen direct thrombin inhibitor assay and ecarin clotting time, limited specificity of Hemoclot direct thrombin inhibitor assay poses a high risk of unnecessary anticoagulation reversal or treatment delays in patients on dabigatran. While AXA accurately detected rivaroxaban, the impact of low apixaban levels on the assay was weak. Hence, AXA results need to be interpreted with extreme caution when used to assess hemostatic function in patients on apixaban.

Clinical Trial Registration

URL: https://www.clinicaltrials.gov. Unique identifiers: NCT02371044, NCT02371070.

Idarucizumab for Reversal of Dabigatran in Early/Emergency Surgeries: A Case Series

BACKGROUND

Idarucizumab is a humanized, monoclonal antibody fragment used specifically to reverse the anticoagulant effects of dabigatran.

CASE REPORTS

We discuss 4 cases of patients who were treated with idarucizumab to reverse dabigatran before early/emergency surgery. Two of the patients had subdural hematomas, 1 had a splenic laceration, and 1 had Fournier gangrene. All patients received 5 g of idarucizumab before surgery. Intraoperative blood loss in all patients was normal, no adverse events were reported, and the patients recovered normally. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: The case reports presented provide detailed, practical, real-world experience beyond that reported in other case reports and the Reversal Effects of Idarucizumab on Active Dabigatran study. This can help guide clinicians on how idarucizumab can reverse the anticoagulant effect of dabigatran in emergency situations, including patients with subdural hematoma. Our experience suggests that idarucizumab may be a safe and effective antidote to the effects of dabigatran in real-life bleeding situations involving early or emergency surgeries.

Salvage therapy for subclavian artery perforation resulting in mediastinal hematoma during percutaneous coronary intervention: A case report

RATIONALE

Transradial access (TRA) is a widely used technique during percutaneous coronary intervention (PCI). However, mediastinal and cervical hematomas, the rare and severe complications of transradial approach, have extremely high mortality rates. To the best of our knowledge, there were no medical literatures about the successful anticoagulation reversal procedure of mediastinal hematoma in PCI till now.

PATIENT CONCERNS

We here present a 54-year-old male Han patient who underwent PCI. Immediately after PCI, he reported an episode of neck and chest discomfort, dyspnea, cough recurrence, and cold sweats. Emergency chest computed tomography (CT) revealed a perforation of the subclavian artery resulting in a large mediastinal hematoma with potentially lethal tracheal compression.

DIAGNOSIS

A diagnosis of the large mediastinal hematoma was made based on the enhanced computed tomography.

INTERVENTIONS

The patient was successfully managed with palliative therapy of anticoagulation reversal instead of a covered stent graft and surgical operation.

OUTCOMES

Angiography confirmed the absence of leakage after anticoagulation reversal. The patient had an apparent remission of clinical dyspnea. Follow-up CT confirmed an almost entire absorption of the mediastinal hematoma 35 days postdischarge.

LESSONS

The current case highlights the importance of anticoagulation reversal as well as careful guidewire and guide catheter manipulation by the radial approach. Early evaluation, prompt identification, appropriate treatment, and close monitoring are all essential for invasive cardiology.

STS/SCA/AmSECT Clinical Practice Guidelines: Anticoagulation during Cardiopulmonary Bypass

Despite more than a half century of "safe" cardiopulmonary bypass (CPB), the evidence base surrounding the conduct of anticoagulation for CPB has not been organized into a succinct guideline. For this and other reasons, there is enormous practice variability relating to the use and dosing of heparin, monitoring heparin anticoagulation, reversal of anticoagulation, and the use of alternative anticoagulants. To address this and other gaps, the Society of Thoracic Surgeons (STS), the Society of Cardiovascular Anesthesiologists (SCA), and the American Society of Extracorporeal Technology (AmSECT) developed an Evidence Based Workgroup. This was a group of interdisciplinary professionals gathered together to summarize the evidence and create practice recommendations for various aspects of CPB. To date, anticoagulation practices in CPB have not been standardized in accordance with the evidence base. This clinical practice guideline was written with the intent to fill the evidence gap and to establish best practices in anticoagulation for CPB using the available evidence. To identify relevant evidence a systematic review was outlined and literature searches were conducted in PubMed® using standardized MeSH terms from the National Library of Medicine list of search terms. Search dates were inclusive of January 2000 to December 2015. The search yielded 833 abstracts which were reviewed by two independent reviewers. Once accepted into the full manuscript review stage, two members of the writing group evaluated each of 286 full papers for inclusion eligibility into the guideline document. Ninety-six manuscripts were included in the final review. In addition, 17 manuscripts published prior to 2000 were included to provide method, context, or additional supporting evidence for the recommendations as these papers were considered sentinel publications. Members of the writing group wrote and developed recommendations based on review of the articles obtained and achieved more than two thirds agreement on each recommendation. The quality of information for a given recommendation allowed assessment of the level of evidence as recommended by the AHA/ACCF Task Force on Practice Guidelines. Recommendations were written in the three following areas 1) Heparin dosing and monitoring for initiation and maintenance of CPB, 2) Heparin contraindications and heparin alternatives, 3) Reversal of anticoagulation during cardiac operations. It is hoped that this guideline will serve as a resource and will stimulate investigators to conduct more research and expand upon the evidence base on the topic of anticoagulation for CPB.

Three- versus four-factor prothrombin complex concentrate for the reversal of warfarin-induced bleeding

Objective:

The objective of this study was to evaluate the effectiveness of 3-factor prothrombin complex concentrate (3F-PCC) compared to 4-factor PCC (4F-PCC) in warfarin-associated bleeding.

Methods:

This multicenter, retrospective, cohort study analyzed data from patients admitted between May 2011 and October 2014 who received PCC for warfarin-associated bleeding. The primary outcome was the rate of international normalized ratio (INR) normalization, defined as an INR ≤1.3, after administration of 3F-PCC compared to 4F-PCC. Other variables of interest included the incidence of additional reversal agents, new thromboembolic events, and mortality.

Results:

A total of 134 patients were included in the analysis. The average dose of PCC administered was 24.6 ± 9.3 units/kg versus 36.3 ± 12.8 units/kg in the 3F-PCC and 4F-PCC groups, respectively, P < 0.001. Baseline INR in the 3F-PCC and 4F-PCC groups was 3.61 ± 2.3 and 6.87 ± 2.3, respectively P < 0.001. 4F-PCC had a higher rate of INR normalization at first INR check post-PCC administration compared to 3F-PCC (84.2% vs. 51.9%, P = 0.0001). Thromboembolic events, intensive care unit and hospital length of stay, and mortality were similar among both groups.

Conclusion:

The use of 4F-PCC leads to a more significant reduction in INR compared to 3F-PCC though no difference in mortality or length of stay was observed. Thromboembolism rates were similar among both groups.

Healthcare resource utilization in patients receiving idarucizumab for reversal of dabigatran anticoagulation due to major bleeding, urgent surgery, or procedural interventions: interim results from the RE-VERSE AD™ study

AIMS

Patients treated with anticoagulants may experience serious bleeding or require urgent surgery or intervention, and may benefit from rapid anticoagulant reversal. This exploratory analysis assessed healthcare resource utilization (HCRU) in patients treated with idarucizumab, a specific reversal agent for dabigatran etexilate.

MATERIALS AND METHODS

RE-VERSE AD™ (NCT02104947), a prospective, multi-center open-label study, is evaluating idarucizumab for dabigatran reversal in patients with serious bleeding (Group A) or undergoing emergency surgery/procedures (Group B). HCRU outcome measures evaluated in the first 90 patients enrolled were use of blood products and pro-hemostatic agents, length of stay (LOS) in hospital, and LOS in intensive care unit (ICU).

RESULTS

Blood products or pro-hemostatic agents were given to 63% (32/51) of patients in Group A and 23% (9/39) of patients in Group B on the day of/day after surgery. An overnight hospital stay was reported for 82% (42/51) of patients in Group A with median LOS = 7 (range = 1-71) bed-days. For Group B, 92% (36/39) had an overnight hospital stay with a median LOS = 9 (range = 1-92) bed-days. In Group A, 17 patients were admitted to the ICU for at least 1 day with median LOS = 4 (range = 1-44) days; in Group B the number was 15 with median LOS = 2 (range = 1-92) days.

LIMITATIONS

The lack of a control group and the small patient numbers limit the strength of the conclusions.

CONCLUSIONS

The use of idarucizumab may simplify emergency management of dabigatran-treated patients with life-threatening bleeds and reduce perioperative complications in patients undergoing emergency surgery.

Medical Treatment for Spontaneous Anticoagulation-Related Intracerebral Hemorrhage in the Netherlands

BACKGROUND

Spontaneous anticoagulation-related intracerebral hemorrhage accounts for up to a quarter of spontaneous intracerebral hemorrhage cases and is associated with higher hematoma volume and a worse outcome. Guidelines recommend rapid anticoagulant reversal but mode and timing are not specified and optimal strategy is uncertain. Variability in everyday practice is unknown.

METHODS

An invitation to a web-based survey was sent to 85 Dutch stroke neurologists in different hospitals, with questions about importance, timing, and medical management of spontaneous anticoagulation-related intracerebral hemorrhage.

RESULTS

In total, 61 (72%) neurologists completed the survey. Nearly all (97%) deemed rapid anticoagulant reversal important. A local guideline for management of anticoagulant reversal was used in 80% of the hospitals. Most neurologists (56%) estimated anticoagulant reversal in anticoagulation-related intracerebral hemorrhage to start later than intravenous thrombolysis in ischemic stroke. Few (5%) thought it was quicker. A minority (28%) of the hospitals started anticoagulation reversal without waiting for laboratory test results or consulting a specialist in hemostasis. Prothrombin complex concentrate was used by all neurologists for vitamin K antagonist reversal and by most (74%) for reversal of thrombin inhibitors and factor Xa inhibitors (72%). Anticoagulation reversal was initiated at the emergency department according to 89% of the respondents.

CONCLUSION

Variability in logistics in acute management of spontaneous anticoagulation-related intracerebral hemorrhage was demonstrated. Anticoagulant reversal is deemed important, but is estimated to have a longer door-to-needle time than alteplase in thrombolysis for ischemic stroke by most neurologists. Several delaying factors were found. These factors might have an impact on outcome.

Evaluation of Warfarin Reversal with 4-Factor Prothrombin Complex Concentrate Compared to 3-Factor Prothrombin Complex Concentrate at a Tertiary Academic Medical Center

BACKGROUND

The U.S. Food and Drug Administration recently approved a four-factor prothrombin complex concentrate (4-PCC) for warfarin reversal. The literature supporting its use over three-factor prothrombin complex concentrate (3-PCC) is limited.

OBJECTIVE

Our objective was to retrospectively compare the efficacy of 3-PCC to 4-PCC in reversing warfarin in patients who were actively bleeding.

METHODS

We conducted a single-center, retrospective cohort analysis of adult patients who received 3-PCC or 4-PCC for international normalized ratio (INR) reversal. Our study excluded patients not actively bleeding and not on warfarin. The main outcome was the percentage of patients who achieved warfarin reversal defined as INR ≤ 1.3 at first INR check post factor administration. We recorded baseline data including PCC dose, location of bleed, pre- and posttreatment INR, and time to INR reversal.

RESULTS

We included a total of 53 patients. Intracranial hemorrhage was the most common site of bleeding (26 [74.3%] in 3-PCC vs. 12 [66.7%] in 4-PCC). The mean dose of 3-PCC was 25.5 units/kg, compared to 27.9 units/kg of 4-PCC. The mean baseline INR was 2.3 in the 3-PCC group and 3 in the 4-PCC group (p = 0.03), and the first posttreatment INRs were 1.4 and 1.2, respectively (p < 0.01). Warfarin reversal was achieved in 15 (42.9%) patients who received 3-PCC and 15 (83.3%) patients who received 4-PCC (p < 0.01). Faster time to INR reversal was noted in the 4-PCC group vs. the 3-PCC group (3.7 vs. 5 h, p = 0.48).

CONCLUSION

A higher percentage of patients achieved warfarin reversal with 4-PCC compared to 3-PCC treatment. A prospective randomized control trial is necessary to confirm our results.

How we treat bleeding associated with direct oral anticoagulants

Direct oral anticoagulants are at least as effective as vitamin K antagonists for the prevention and treatment of thromboembolism. Unfortunately, differently from vitamin K antagonists, they have the great drawback of lacking specific antidotes in the case of bleeding or emergency situations such as trauma, stroke requiring thrombolysis, and urgent surgery. The progressive development of antidotes for these new drugs, which, it is hoped, will become available in the near future, will allow better and safer management of the rapid reversal of their anticoagulant effect.

Anticoagulation Reversal with Prothrombin Complex Concentrate in Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Intracerebral hemorrhage is a well-recognized complication of anticoagulation therapy. However, there are only a few reports that address the management of aneurysmal subarachnoid hemorrhage (aSAH) in anticoagulated patients.

OBJECTIVE

We report on our experiences with the use of prothrombin complex concentrate (PCC) for rapid anticoagulation reversal in aSAH.

METHODS

We retrospectively analyzed our institutional database of consecutive patients who received PCC between February 2006 and August 2014 (n > 1000). Data from all anticoagulated patients referred to our hospital for aSAH and those who received PCC were included in this analysis. Patient characteristics as well as treatment modalities were analyzed, with specific focus on results of laboratory examination, PCC administration and bleeding, and thromboembolic complications during the later course.

RESULTS

In total, only 9 patients (< 1% of all aSAH patients treated at our institution during the study period) had been anticoagulated at admission. Median international normalized ratio (INR) of patients at admission was 2.31 (interquartile range [IQR] 1.83-2.97) and after median administration of 2500 IU (IQR 2000-3000 IU) PCC, median INR significantly decreased to 1.15 (IQR 1.07-1.19). Surgical and interventional procedures were initiated within a median of 3.9 h (IQR 1.7-9.3 h) after admission. No hemorrhagic or thromboembolic events occurred later in the course. A favorable outcome according to the Glasgow Outcome Scale (scores of 4 and 5) was achieved in 6 patients (67%).

CONCLUSIONS

Aneurysmal SAH in anticoagulated patients is a rare condition. PCC is an effective option to rapidly reverse anticoagulation in aSAH and might facilitate achieving a favorable outcome in these patients.

An evaluation of intravenous vitamin k for warfarin reversal: are guideline recommendations being followed?

BACKGROUND

Vitamin K antagonists (eg, warfarin) remain the mainstay of anticoagulation therapy in the United States, with over 22 million prescriptions being filled annually. Unfortunately, warfarin therapy is difficult to manage and increases bleeding risk. The 2012 American College of Chest Physicians guidelines created a warfarin reversal algorithm that suggested the stringent use of intravenous vitamin K.

OBJECTIVE

The purpose of this evaluation was to determine the rates of adherence with guideline recommendations in clinical practice.

METHOD

A convenience sample of 3 months of intravenous vitamin K medication administration data (September to November 2013) was obtained to conduct a retrospective review. Patients with underlying hepatic dysfunction or lack of warfarin therapy were excluded. Vitamin K use was evaluated for consistency with the 2012 guidelines.

RESULTS

A total of 364 patients were reviewed and 119 were included. Vitamin K utilization was consistent with guideline recommendations for a total of 30 (25.2%) patients. The most common site of active bleeding requiring reversal was head bleeds, consisting of 56.6% of bleeds. A single dose of 10 mg of vitamin K was the most frequently used dosing strategy. Fresh frozen plasma (73.3%) and four-factor prothrombin complex concentrate (36.7%) were the most commonly used factor products.

CONCLUSION

This evaluation demonstrates that there is a difference between clinical judgment and guideline adherence. True adherence with the guidelines may not be necessary; however, there is room for improvement in both the appropriateness and safety of intravenous vitamin K use.

Management of dabigatran-associated intracerebral and intraventricular hemorrhage: a case report

BACKGROUND

Dabigatran is an oral, reversibly bound, direct thrombin inhibitor currently approved in the United States for prevention of stroke and systemic embolism in patients with nonvalvular atrial fibrillation. In the phase III trial leading to approval of the agent, the incidence of life-threatening bleeding was 1.80%/year in the dabigatran 150 mg twice daily arm. Because there is no direct antidote or reversal agent for this drug, the need to manage life-threatening hemorrhages with procoagulant products will arise.

OBJECTIVE

To describe a case of dabigatran-associated intracerebral and intraventricular hemorrhage and subsequent management with activated prothrombin complex concentrate.

CASE REPORT

An 85-year-old man currently taking dabigatran 150 mg twice daily presented to the Emergency Department for incoordination, expressive aphasia, and weakness. A computed tomography image of his head demonstrated an intracranial hemorrhage. The last dose of dabigatran was approximately 14 h prior to arrival, and conventional coagulation assays (thrombin time and activated partial thromboplastin time) confirmed the presence of dabigatran in the patient's serum. The patient received 27.5 units/kg of activated prothrombin complex concentrate (FEIBA®; Baxter Healthcare Corporation, Deerfield, IL) after an initial intravenous fluid bolus. His activated partial thromboplastin time was not completely normalized by the use of FEIBA; however, the patient's neurological examination slightly improved and remained stable throughout his hospital course despite some intraventricular expansion of the hematoma. After discharge to physical rehabilitation, the patient developed an ischemic cerebrovascular accident and was discharged home on hospice.

CONCLUSION

Due to lack of an available antidote, activated prothrombin complex concentrate was utilized as a nonspecific procoagulant to stabilize an intracerebral hemorrhage in a patient on dabigatran.

Evaluation of education on the appropriate use of vitamin k in warfarin reversal in adult inpatients

PURPOSE

Vitamin K (phytonadione) is a commonly used first-line reversal agent for vitamin K antagonist (VKA) therapy in patients presenting with a supratherapeutic international normalized ratio (INR) with or without significant bleeding or in patients with a therapeutic INR in need of surgery. The purpose of this study was to determine the impact of education on the appropriate use of vitamin K for VKA reversal.

METHODS

Data were collected on patients admitted to a community teaching hospital during February 2010 (pre-education group). These data were analyzed to determine the most common guideline deviations in vitamin K use. Following this analysis, pharmacist education took place in the form of in-service presentations; a protocol, including a guideline-based dosing table, was developed to assist pharmacists in evaluating vitamin K therapy. Data were then collected on patients admitted during February 2011 (post-education group).

RESULTS

Forty patients and 47 vitamin K administrations were included in the pre-education group, and 34 patients and 49 vitamin K administrations were included in the post-education group. The number of patients with appropriate vitamin K administrations improved after pharmacist education (25% pre-education vs 55.8% post-education; P = .01). Whereas 27.6% of individual vitamin K administrations were appropriate in the pre-education group, this increased to 63.2% in the post-education group (P = .04).

CONCLUSION

Education techniques on the appropriate use of vitamin K for VKA reversal significantly improved compliance with standards of care for proper use of vitamin K. Additional education sessions are necessary to further increase compliance with standards of care and subsequently optimize patient care.

Use of Prothrombin Complex Concentrate for Vitamin K Antagonist Reversal before Surgical Treatment of Intracranial Hemorrhage

Background:

Oral anticoagulant therapy (OAT) is used to prevent/treat thromboembolism. Major bleeding is common in patients on OAT; eg, warfarin increases intracranial hemorrhage (ICH) risk.

Case:

A 71-year-old male on warfarin (to reduce stroke risk) presented at Accident and Emergency Minor Injuries Unit with headache after reportedly sounding ‘drunk’. On triage, the patient appeared lucid and well. However, International Normalized Ratio (INR) was 4.1. Head computed tomography (CT) indicated a large right-sided subdural hematoma. Prothrombin complex concentrate (PCC; Beriplex^® P/N, CSL Behring) with vitamin K normalized the INR within minutes of administration. The patient underwent neurosurgery without complications, and was discharged after 5 days, with no residual neurological symptoms.

Conclusions:

ICH patients can present with no neurological signs. In OAT patients with headache, INR must be established; if ≥3.0, normalization of INR and head CT are essential. PCC is the best option to rapidly reverse anticoagulation and correct INR pre-surgery.