Anticoagulant Reversal Strategies in the Emergency Department Setting: Recommendations of a Multidisciplinary Expert Panel

Comparison of anticoagulation reversal strategies for warfarin associated acute gastrointestinal bleeding

OBJECTIVE

Gastrointestinal bleeding (GIB) is a common complication associated with warfarin use. However, the optimal approach for anticoagulation reversal-whether with prothrombin complex concentrate (PCC), fresh frozen plasma (FFP), vitamin K (intravenous or oral), or no reversal-remains unclear as current literature and society guidelines do not provide definitive recommendations.

METHODS

A retrospective analysis of emergency department patients with warfarin-associated GIB who presented to an academic health system was performed, comparing reversal with PCC, FFP, vitamin K only, or no reversal agent. The primary outcome was 30-day all-cause mortality. Secondary outcomes included rebleeding events and 30-day thrombotic events. Standardized guidelines for reporting were followed (STROBE).

RESULTS

Of 815 patients, within 12 h of presentation, 10.7 % received reversal with PCC (with or without vitamin K), 12.9 % with FFP (with or without vitamin K), and 34.9 % with vitamin K alone; 41.5 % of patients received no reversal agent. Compared to all other groups, patients receiving PCC had significantly higher 30-day mortality (18.4 % [PCC] vs 5.7 % [FFP] vs 4.6 % [vitamin K] vs 5.6 % [no reversal], p < 0.001), which remained significant after adjusting for hemodynamic instability and ICU admission. There were no significant differences in rates of thrombotic event within 30 days (3.4 % vs 3.8 % vs 1.4 % vs 1.2 %, p = 0.20).

CONCLUSIONS

Patients who received PCC had a threefold increase in mortality compared to FFP, vitamin K alone, or no reversal, even after adjusting for severity of the bleeding. Further research is necessary to understand factors leading to this observed mortality difference among patients with warfarin related GIB.

Efficacy and Safety of Andexanet Alfa Versus Four Factor Prothrombin Complex Concentrate for Emergent Reversal of Factor Xa Inhibitor Associated Intracranial Hemorrhage: A Systematic Review and Meta-Analysis

Factor Xa inhibitors (FXaI) are increasingly used for anticoagulation therapy, yet their association with intracranial hemorrhage poses a significant challenge. Although andexanet alfa (AA) and four-factor prothrombin complex concentrate (4F-PCC) have shown promise in reversing FXaI effects, their comparative efficacy and safety remain uncertain. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we conducted a literature search on electronic databases to obtain the relevant studies until May 16, 2024. Our primary outcomes were successful anticoagulation reversal, overall mortality (including 30-day and in-hospital mortality), and thromboembolic events. Secondary outcomes were length of hospital and intensive care unit stay and hematoma volume expansion. Data were pooled using a random-effects model. We included 16 eligible studies with a total of 2,977 patients. A statistically significant improvement in hemostatic efficacy rates was in favor of the AA group (risk ratio [RR] 1.10, 95% confidence interval [CI] 1.01-1.20, P = 0.02). Lower overall mortality rates were found in the AA group (RR 0.67, 95% CI 0.51-0.88, P = 0.004). However, no difference was found in 30-day mortality rates (RR 0.82, 95% CI 0.58-1.16, P = 0.26). In terms of thromboembolic events, more events were found in the AA group (RR 1.47, 95% CI 1.01-2.15, P = 0.046). AA was associated with a longer duration of hospital stay compared to 4F-PCC (mean difference [MD] 0.64, 95% CI 0.07-1.22, P = 0.03). Neither a significant difference in length of intensive care unit stay (MD 0.25, 95% CI - 0.36 to 0.86, P = 0.41) nor a significant difference in hematoma volume expansion was reported (MD - 0.89, 95% CI - 3.11 to 1.34, P = 0.435). Our results suggest that AA is superior to 4F-PCC in enhancing the hemostatic efficacy and reducing the overall and in-hospital mortality rates. More thromboembolic events are thought to be associated with the use of AA. However, more studies are required to validate whether the better results of AA in improving hemostatic efficacy are enough to make up for their higher cost and their possible risk of thromboembolic events.

Anticoagulation reversal (vitamin K, prothrombin complex concentrates, idarucizumab, andexanet-α, protamine)

Bleeding events are common in patients prescribed anticoagulants and can have devastating consequences. Several specific and nonspecific agents have been developed to reverse the effects of anticoagulant drugs or toxins. Vitamin K, as the oldest of these antidotes, specifically counteracts the effects of pharmaceuticals and rodenticides designed to deplete stores of vitamin K-dependent factors. In cases of life-threatening bleeding, the addition of prothrombin complex concentrates (PCCs) allows for the immediate replacement of coagulation factors. While the use of PCCs has been extended to the non-specific reversal of the effects of newer direct oral anticoagulants, the specific agents idarucizumab, targeting dabigatran and andexanet-α, binding factor Xa inhibitors, have recently been developed and are being preferentially recommended by most guidelines. However, despite having rapid effects on correcting coagulopathy, there is to date a lack of robust evidence establishing the clear superiority of direct oral anticoagulant-specific reversal agents over PCCs in terms of haemostatic efficacy, safety or mortality. For andexanet-α, a potential signal of increased thromboembolic risks, comparatively high costs and low availability might also limit its use, even though emerging evidence appears to bolster its role in intracranial haemorrhage. Protamine is the specific agent for the reversal of unfractionated heparin anticoagulation used mainly in cardiovascular surgery. It is much less effective for low molecular weight heparin fragments and is usually reserved for cases with life-threatening bleeding.

Development of a Medication-Use Evaluation Template for Andexanet Alfa in the Reversal of Anticoagulation With Factor Xa Inhibitors

Medication-use evaluations are meant to ensure that medication-use processes are consistent with prevailing standards of care, assure optimal use of therapy, and reduce the risk of medication-related problems. Reversal agents for direct oral anticoagulants are a worthy focus for medication-use evaluations for reasons of efficacy, safety, and cost. A multidisciplinary team of experts developed 2 medication-use evaluation templates illustrating the application of professional society guidelines to the appropriate use of andexanet alfa.

Prediction and prevention of post-procedural bleedings in patients with cirrhosis

Although post-procedural bleedings are infrequent in patients with cirrhosis, they are associated with significant morbidity and mortality. Therefore, predicting and preventing such bleedings is important. Established predictors of post-procedural bleeding include high-bleeding risk procedure, severe cirrhosis and high body mass index; prognostic value of anemia, acute kidney injury and bacterial infection is more uncertain. While prothrombin time and international normalized ratio do not predict post-procedural bleeding, some evidence suggests that platelet count, whole blood thrombin generation assay and viscoelastic tests may be helpful in this context. Prevention of postprocedural bleeding involves careful management of antithrombotic drugs during the periprocedural period. Patients with cirrhosis present unique challenges due to altered pharmacokinetics and pharmacodynamics of antithrombotic drugs, but there is a lack of dedicated studies specifically focused on this patient population. Guidelines for periprocedural management of antithrombotic drugs developed for patients without liver disease are thus applied to those with cirrhosis. Some technical aspects may decrease the risk of post-procedural bleeding, namely ultrasoundguidance, opting for transjugular route rather than percutaneous route, and the level of expertise of the operator. The effectiveness of platelet transfusions or thrombopoietin-receptor agonists remains uncertain. Transfusion of fresh-frozen plasma, of fibrinogen, and administration of tranexamic acid are not recommended for reducing post-procedural bleeding in patients with cirrhosis. In conclusion, prediction of post-procedural requires a global approach taking into account the patients characteristics, the risk of the procedure, and the platelet count. There is little data to support prophylactic correction of hemostasis, and dedicated studies are needed.

Assessing the effectiveness of a rural distribution program in reducing time to prothrombin complex concentrate administration in patients taking warfarin

STUDY OBJECTIVES

Reversal of warfarin-induced anticoagulation using prothrombin complex concentrate (PCC4) is more rapidly achieved than with traditional methods, such as fresh frozen plasma (FFP). In many rural facilities, the availability of both FFP and PCC4 has been limited. A tertiary hospital instituted a program to provide PCC4 to rural sites using an air transport team and pharmacy exchange. We hypothesized that increasing accessibility of PCC4 would shorten time to INR reversal.

METHODS

This was a retrospective study with the primary outcome being time to INR reversal (INR ≤ 1.6) and time to PCC4 administration from outside hospital admission. Active warfarin prescription, transfer to a tertiary facility, and administration of anticoagulation reversal between January 2013 and December 2020 were required for inclusion. Patients were grouped by dates before and after implementation of the program in August 2016. Linear regressions were performed to determine the effect of the variable and INR reversal methods on the time to INR reversal as well as the time to PCC4 administration. Time-to-event analysis was used to analyze the primary outcome between comparison groups. p values of less than 0.05 were considered significant.

RESULTS

Chart review identified 189 patients: 56 within the pre-implementation group and 133 within the post-implementation group. Statistics were compared between these two groups. The post-implementation group had a shorter time to INR reversal (median 9.97 h) compared with the pre-implementation group (median 14.58 h, p = 0.00004). Time to PCC4 administration was also significantly decreased (p = 0.023). No statistically significant differences were found for hospital survival or 30-day mortality.

CONCLUSION

In rural hospitals, increasing availability of PCC4 using air medical transport along with a medication exchange program significantly reduces time to PCC4 administration in warfarin anticoagulated patients.

3-Factor prothrombin complex concentrate versus 4-factor prothrombin complex concentrate for the reversal of oral factor Xa inhibitors

Multiple agents exist for the reversal of oral Factor Xa inhibitor (FXa) associated bleeding, including Coagulation FXa Recombinant, Inactivated zhzo (andexanet alfa) and 4-factor prothrombin complex concentrate (4F-PCC). While classified as a 3F-PCC product, Profilnine contains up to 35 IU of Factor VII (per 100 IU of Factor IX) in addition to therapeutic levels of Factors II, IX, and X, and has demonstrated a similar impact on prothrombin time and blood product usage in non-warfarin related bleeding. This was a retrospective, multicenter study at four medical centers of adult patients who presented with major bleeding associated with oral FXa inhibitors and received either 4F-PCC (n = 64) or 3F-PCC (n = 61). The primary outcome was hemostatic effectiveness. Secondary outcomes included the incidence of thromboembolism, in-hospital mortality, and length of stay. The most common indication for reversal was intracranial bleeding. For the primary outcome, 84% of all patients were rated as effective with no difference noted between the groups (p = 0.81). No significant difference between groups was found in the multivariable analysis adjusting for baseline differences between groups including race, total body weight, type of bleeding, and the use of antiplatelet therapy. There was no difference in the length of stay, in-hospital mortality, or the incidence of thromboembolism between the groups. Overall, no significant differences were found in the effectiveness or safety of 4F-PCC and 3F-PCC use in the management of oral FXa inhibitor-associated bleeding. Further investigations are warranted to explore the use of 3F-PCC for this indication and its safety and effectiveness.

Long-Term Safety of a Four-Factor Prothrombin Complex Concentrate (Kcentra®/Beriplex® P/N): An Updated Pharmacovigilance Review

INTRODUCTION

 Four-factor prothrombin complex concentrate (4F-PCC) is recommended for vitamin K antagonist reversal in patients with major bleeding or in need of surgery. The most important risk associated with the use of 4F-PCC is the occurrence of thromboembolic events (TEEs). In this review, we aim to evaluate the safety profile of a 4F-PCC (Kcentra®/Beriplex® P/N; CSL Behring, Marburg, Germany) by reviewing pharmacovigilance data.

METHODS

 A retrospective analysis of postmarketing pharmacovigilance data of Kcentra®/Beriplex® P/N from February 1996 to April 2022 was performed and complemented by a review of clinical studies published between January 2012 and April 2022.

RESULTS

 A total of 2,321,443 standard infusions of Kcentra®/Beriplex® P/N were administered during the evaluation period. Adverse drug reactions (ADRs) were reported in 614 cases (∼1 per 3,781 standard infusions) and 233 of these cases (37.9%) experienced suspected TEEs related to 4F-PCC (∼1 per 9,963 standard infusions); most of these cases had pre-existing or concomitant conditions likely to be significant risk factors for thrombosis. TEE rates were similar when 4F-PCC was used on-label or off-label for direct oral anticoagulant-associated bleeding. Thirty-six cases (5.9%) reported hypersensitivity type reactions (∼1 per 64,485 standard infusions). No confirmed case of viral transmission related to 4F-PCC use was reported. The published literature also revealed a favorable safety profile of 4F-PCC.

CONCLUSION

 Analysis of postmarketing pharmacovigilance safety reports demonstrated that treatment with 4F-PCC was associated with few ADRs and a low rate of TEEs across multiple indications and settings, thus confirming a positive safety profile of 4F-PCC.

Urgent Reversal of Direct Oral Anticoagulants in Critical and Life-Threatening Bleeding: A Multidisciplinary Expert Consensus

Direct oral anticoagulants (DOACs) are increasingly being used due to their improved efficacy/safety ratio and lower clinical and economic burden when compared to vitamin K antagonists. However, bleeding is still the most frequent complication associated with DOACs, and although rare, bleeding episodes can be life-threatening or critical. The impact of DOAC anticoagulation activity during a bleeding event must be evaluated according to patient clinical assessment, dosage and time from last intake, the presence of comorbidities (especially kidney and liver dysfunction), and, whenever possible, coagulation tests. Unfortunately, DOACs' anticoagulation activity is not easily or usually detectable in routine common coagulation testing. Specific DOAC tests allow for specific drug monitoring, but they are too time consuming, and are usually unavailable in routine emergency practice. If a clinically relevant DOAC plasma concentration is assumed or proven in a severe bleeding scenario, DOAC reversal is needed to restore hemostasis. This experts' consensus provides a narrative review about DOAC reversal and practical life-threatening bleeding management in several scenarios (trauma, intracranial hemorrhage and gastrointestinal bleeding), focusing on the selection of patients to whom specific reversal agents should be given.

Drug Interactions between Androgen Receptor Axis-Targeted Therapies and Antithrombotic Therapies in Prostate Cancer: Delphi Consensus

Background/Objectives: Abiraterone acetate, apalutamide, darolutamide, and enzalutamide, which make up the androgen receptor axis-targeted therapies (ARATs) drug class, are commonly used in the management of prostate cancer. Many patients on ARATs also receive oral antithrombotic therapy (i.e., anticoagulants or antiplatelets). The concomitant use of ARATs and antithrombotic therapies creates the potential for clinically relevant drug-drug interactions, but the literature regarding the actual consequences of these interactions, and guidance for co-prescribing, is limited. We assembled a multidisciplinary panel of experts and provided them with clinical information derived from a comprehensive literature review regarding the drug-drug interactions between ARATs and antithrombotic therapies. Methods: A three-stage modified electronic Delphi process was used to gather and consolidate opinions from the panel. Each stage consisted of up to three rounds of voting to achieve consensus on which ARAT/antithrombotic therapy drug pairs warrant attention, the possible clinical consequences of drug-drug interactions, and suggested actions for management. Results: The panel achieved consensus to avoid 11 ARAT/antithrombotic therapy drug pairs and modify therapy for eight pairs. Assessments relied heavily on pharmacokinetic data and extrapolation from drug-drug interaction studies of similarly metabolized drugs. Conclusions: This e-Delphi process highlights the need for further research into the clinical impact of ARAT/antithrombotic drug interactions. Nonetheless, the suggested actions aim to provide clinicians with a practical framework for therapeutic decision making.

Modelling the effects of 4-factor prothrombin complex concentrate for the management of factor Xa-associated bleeding

The management of factor Xa (FXa) inhibitor-associated bleeding remains a clinical challenge. Massive bleeding is often associated with complex coagulopathy and, thus, the sole reversal of FXa inhibitors might not be sufficient to restore hemostasis, requiring instead a multimodal approach. Four-factor prothrombin complex concentrate (4F-PCC) is widely recognized as a viable treatment option for FXa inhibitor-associated bleeding. Here, we applied computational models to explore the effect 4F-PCC has on the coagulation cascade and restoration of thrombin generation in a system that simulates a patient that has received a FXa inhibitor. The coagulation model is largely based on a previously developed model with modifications incorporated from various other published sources. The model was calibrated and validated using data from a phase 3 clinical trial of vitamin K antagonist reversal with 4F-PCC. Using the parameters and initial conditions determined during the calibration and validation process, the prothrombin time (PT) test simulations predicted a PT of 11.4 seconds. The model successfully simulated the effects of rivaroxaban and apixaban on total thrombin concentration and showed that 4F-PCC increased thrombin generation in the presence of rivaroxaban or apixaban.

Perioperative Management of Patients Taking Direct Oral Anticoagulants: A Review

Importance

Direct oral anticoagulants (DOACs), comprising apixaban, rivaroxaban, edoxaban, and dabigatran, are commonly used medications to treat patients with atrial fibrillation and venous thromboembolism. Decisions about how to manage DOACs in patients undergoing a surgical or nonsurgical procedure are important to decrease the risks of bleeding and thromboembolism.

Observations

For elective surgical or nonsurgical procedures, a standardized approach to perioperative DOAC management involves classifying the risk of procedure-related bleeding as minimal (eg, minor dental or skin procedures), low to moderate (eg, cholecystectomy, inguinal hernia repair), or high risk (eg, major cancer or joint replacement procedures). For patients undergoing minimal bleeding risk procedures, DOACs may be continued, or if there is concern about excessive bleeding, DOACs may be discontinued on the day of the procedure. Patients undergoing a low to moderate bleeding risk procedure should typically discontinue DOACs 1 day before the operation and restart DOACs 1 day after. Patients undergoing a high bleeding risk procedure should stop DOACs 2 days prior to the operation and restart DOACs 2 days after. With this perioperative DOAC management strategy, rates of thromboembolism (0.2%-0.4%) and major bleeding (1%-2%) are low and delays or cancellations of surgical and nonsurgical procedures are infrequent. Patients taking DOACs who need emergent (<6 hours after presentation) or urgent surgical procedures (6-24 hours after presentation) experience bleeding rates up to 23% and thromboembolism as high as 11%. Laboratory testing to measure preoperative DOAC levels may be useful to determine whether patients should receive a DOAC reversal agent (eg, prothrombin complex concentrates, idarucizumab, or andexanet-α) prior to an emergent or urgent procedure.

Conclusions and Relevance

When patients who are taking a DOAC require an elective surgical or nonsurgical procedure, standardized management protocols can be applied that do not require testing DOAC levels or heparin bridging. When patients taking a DOAC require an emergent, urgent, or semiurgent surgical procedure, anticoagulant reversal agents may be appropriate when DOAC levels are elevated or not available.

Co-administration of Four-Factor Prothrombin Complex Concentrate With Andexanet alfa for Reversal of Nontraumatic Intracranial Hemorrhage

Objective: Andexanet alfa is approved for the reversal of life-threatening or uncontrolled bleeding due to factor-Xa inhibitors. Data are limited on outcomes for patients who receive both andexanet alfa and 4-factor prothrombin complex concentrate (4F-PCC). The aim of this case series is to evaluate the safety and efficacy outcomes in patients receiving the two agents in combination. Methods: Electronic medical records of patients who received both 4F-PCC and andexanet alfa for nontraumatic intracranial hemorrhage from January 2019 to March 2022 were retrospectively reviewed. Hemostatic efficacy and complications related to concurrent use of 4F-PCC with andexanet alfa were documented. Results: Nine patients received 4F-PCC and andexanet alfa for reversal of factor Xa inhibitor-associated intracranial bleeding, eight of whom required reversal of apixaban. Of these nine patients, five patients died within 28 days for a 56% incidence of mortality. The average time from 4F-PCC administration to andexanet alfa administration was 3 hours and 9 minutes. Most doses of andexanet alfa were given for concern for bleed expansion after 4F-PCC administration. Hemostatic efficacy based on stability of repeat computed tomography scans post-administration of both agents was found in six patients (66.67%), with a 55.56% n incidence of thromboembolism, including two pulmonary embolisms, two deep vein thromboses, and one renal artery thrombosis. Conclusion: Risks and benefits should be weighed to determine if there is benefit to adding andexanet alfa to 4F-PCC in patients with incomplete hemostasis and life-threatening hemorrhage. The combination of andexanet alfa and 4F-PCC may increase the risk of thrombotic complications without improving mortality.

Design and rationale for REVERXaL: A real-world study of patients with factor Xa inhibitor-associated major bleeds

BACKGROUND

The prevalence of anticoagulation treatment is increasing as an aging global population faces a high burden of cardiovascular comorbidities. Direct oral anticoagulants, including factor Xa inhibitors (FXai), are replacing vitamin K antagonists as the most commonly prescribed treatment for reducing risk of thrombotic events. While the risk of FXai-associated spontaneous bleeds is established, less is understood about their management and the effect of treatment on clinical and patient-reported outcomes. The primary objectives of the REVERXaL study are to describe patient characteristics, health care interventions during the acute-care phase, in-hospital outcomes, and associations between timing of reversal/replacement agent administration and in-hospital outcomes. Secondary/exploratory objectives focus on clinical assessments and patient-reported outcome measures (PROMs) at 30 and 90 days.

METHODS

REVERXaL is a multinational, observational study of hospitalized patients with FXai-associated major bleeds in Germany, Japan, the United Kingdom, and the United States. The study includes 2 cohorts of approximately 2000 patients each. Cohort A is a historic cohort for whom medical chart data will be collected from hospitalization to discharge for patients admitted for major bleeds during FXai use within 2 years prior to enrollment of Cohort B. Cohort B will prospectively enroll patients administered any reversal/replacement agent during hospitalization to manage FXai-associated major bleeds and will include the collection of clinical outcomes and PROMs data over 3 months.

CONCLUSIONS

REVERXaL will generate insights on patient characteristics, treatment approaches, and associated outcomes in patients hospitalized with FXai-associated major bleeds. These data may inform clinical practice and streamline treatment pathways in this population.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; unique identifier: NCT06147830.

Antidote-controlled DNA aptamer modulates human factor IXa activity

Thrombosis leads to elevated mortality rates and substantial medical expenses worldwide. Human factor IXa (HFIXa) protease is pivotal in tissue factor (TF)-mediated thrombin generation, and represents a promising target for anticoagulant therapy. We herein isolated novel DNA aptamers that specifically bind to HFIXa through systematic evolution of ligands by exponential enrichment (SELEX) method. We identified two distinct aptamers, seq 5 and seq 11, which demonstrated high binding affinity to HFIXa (Kd = 74.07 ± 2.53 nM, and 4.93 ± 0.15 nM, respectively). Computer software was used for conformational simulation and kinetic analysis of DNA aptamers and HFIXa binding. These aptamers dose-dependently prolonged activated partial thromboplastin time (aPTT) in plasma. We further rationally optimized the aptamers by truncation and site-directed mutation, and generated the truncated forms (Seq 5-1t, Seq 11-1t) and truncated-mutated forms (Seq 5-2tm, Seq 11-2tm). They also showed good anticoagulant effects. The rationally and structurally designed antidotes (seq 5-2b and seq 11-2b) were competitively bound to the DNA aptamers and effectively reversed the anticoagulant effect. This strategy provides DNA aptamer drug-antidote pair with effective anticoagulation and rapid reversal, developing advanced therapies by safe, regulatable aptamer drug-antidote pair.

Andexanet alfa versus non-specific treatments for intracerebral hemorrhage in patients taking factor Xa inhibitors - Individual patient data analysis of ANNEXA-4 and TICH-NOAC

BACKGROUND

Data comparing the specific reversal agent andexanet alfa with non-specific treatments in patients with non-traumatic intracerebral hemorrhage (ICH) associated with factor-Xa inhibitor (FXaI) use are scarce.

AIM

The study aimed to determine the association between the use of andexanet alfa compared with non-specific treatments with the rate of hematoma expansion and thromboembolic complications in patients with FXaI-associated ICH.

METHODS

We performed an individual patient data analysis combining two independent, prospective studies: ANNEXA-4 (180 patients receiving andexanet alfa, NCT02329327) and TICH-NOAC (63 patients receiving tranexamic acid or placebo ± prothrombin complex concentrate, NCT02866838). The primary efficacy outcome was hematoma expansion on follow-up imaging. The primary safety outcome was any thromboembolic complication (ischemic stroke, myocardial infarction, pulmonary embolism, or deep vein thrombosis) at 30 days. We used binary logistic regression models adjusted for baseline hematoma volume, age, calibrated anti-Xa activity, times from last intake of FXaI, and symptom onset to treatment, respectively.

RESULTS

Among 243 participants included, the median age was 80 (IQR 75-84) years, baseline hematoma volume was 9.1 (IQR 3.4-21) mL and anti-Xa activity 118 (IQR 78-222) ng/mL. Times from last FXaI intake and symptom onset to treatment were 11 (IQR 7-16) and 4.7 (IQR 3.0-7.6) h, respectively. Overall, 50 patients (22%) experienced hematoma expansion (ANNEXA-4: n=24 (14%); TICH-NOAC: n=26 (41%)). After adjusting for pre-specified confounders (baseline hematoma volume, age, calibrated anti-Xa activity, times from last intake of FXaI, and symptom onset to treatment, respectively), treatment with andexanet alfa was independently associated with decreased odds for hematoma expansion (aOR 0.33, 95% CI 0.13-0.80, p = 0.015). Overall, 26 patients (11%) had any thromboembolic complication within 30 days (ANNEXA-4: n=20 (11%); TICH-NOAC: n=6 (10%)). There was no association between any thromboembolic complication and treatment with andexanet alfa (aOR 0.70, 95% CI 0.16-3.12, p = 0.641).

CONCLUSION

The use of andexanet alfa compared to any other non-specific treatment strategy was associated with decreased odds for hematoma expansion, without increased odds for thromboembolic complications.

Reversal or Repletion Treatment Strategies and Outcomes of Patients With Major Bleeding Events Managed in the Emergency Department: Large Real-Life Investigation in the Northwestern Healthcare District of Tuscany

OBJECTIVE

To verify the incidence of bleeding events in patients on ongoing anticoagulant treatment in the real world and compare the results of different reversal or repletion strategies currently available for pharmacological treatment.

METHODS

Patients managed in the emergency department (ED) with major bleeding events, on ongoing anticoagulation were stratified according to bleeding site and reversal or repletion therapy with andexanet alfa (ADX), idarucizumab (IDA), prothrombin complex concentrate (PCC), and vitamin K (Vit-K).

ENDPOINT

Death at 30 days was compared in the subgroups with cerebral hemorrhage (CH) and gastrointestinal (GI) bleeding.

RESULTS

Of the 809,397 visits in the years 2022-2023 at 6 EDs in the northwestern health district of Tuscany, 5372 patients with bleeding events were considered; 3740 were excluded due to minor bleeding or propensity score matching. Of the remaining 1632 patients with major bleeding, 548 on ongoing anticoagulation were enrolled; 334 received reversal or repletion agents. Patients with CH (n = 176) and GI bleeding (n = 108) represented the primary analysis cohorts in the study's strategic treatment assessment. Overall, 30-day survival of patients on ongoing aFXa treatment receiving on-label ADX versus off-label PCC showed a relative increase of 71%, while 30-day survival of patients on ongoing aFII receiving on-label IDA versus off-label PCC showed a relative increase of 30%; no substantial difference was found when comparing on-label PCC combined with Vit-K versus off-label Vit-K alone. Indeed, patients undergoing on-label ADX or IDA showed a statistically significant difference over off-label PCC (ADX vs. PCC: n = 15, events = 4, mean ± SD 82.50 ± 18.9, vs. 49, 13, 98.82 ± 27, respectively; analysis of variance [ANOVA] variance 8627; P < 0.001; posthoc test diff 32, 95% confidence interval: 28-35; P < 001; IDA vs. PCC: 20, 5, 32.29 ± 15.0 vs. 2, 1, 28.00 ± 0.0, respectively; ANOVA 1484; P < 0.001; posthoc test -29, -29 -29, respectively; P = n.d.). On-label PCC combined with Vit-K showed overall a slight statistically significant difference versus off-label Vit-K alone (52, 16, 100.58 ± 22.6 vs. 53, 11, 154.62 ± 29.8, respectively; ANOVA 310; P < 0.02; posthoc test 4, 0.7-7.2, respectively; P < 0.02). Data were confirmed in the group of patients with CH (ADX vs. PCC: n = 13, events = 3, mean ± SD 91.55 ± 18.6 vs. 78, 21, 108.91 ± 20.9, respectively; ANOVA variance 10,091, F = 261; P < 0.001; posthoc difference test 36, 95% confidence interval: 30-41; P < 0.001; IDA vs. PCC: 10, 2, 4.50 ± 2.5 vs. 78, 21, 108.91 ± 20.9, respectively; ANOVA 16,876,303, respectively; P < 0.001; posthoc test 41, 34-47, respectively; P < 0.001). On-label PCC combined with Vit-K showed an overall slight statistically significant difference compared with off-label Vit-K alone (P < 0.01 and P < 0.001 in the subgroups of CH and GI bleeding).

CONCLUSIONS

Patients undergoing specific reversal therapy with on-label ADX or IDA, when treated with aFXa or aFII anticoagulants, respectively, showed statistically elevated differences in 30-day death compared with off-label repletion therapy with PCC. Overall, 30-day survival of patients on ongoing aFXa or aFII receiving on-label reversal therapy with ADX or IDA compared with off-label PCC repletion agents showed an increase of 71% and 30%, respectively.

Evaluation and treatment of gastrointestinal bleeding in patients taking anticoagulants presenting to the emergency department

This manuscript is a consensus document of an expert panel on the Evaluation and Treatment of Gastrointestinal Bleeding in Patients Taking Anticoagulants Presenting to the Emergency Department, sponsored by the American College of Emergency Physicians.

Andexanet Alfa versus Four-Factor Prothrombin Complex Concentrate for the Reversal of Factor Xa (FXa) Inhibitor-Associated Intracranial Hemorrhage: A Systematic Review of Retrospective Studies

Background/Objectives: There are limited data on the risks and benefits of using Andexanet alfa (AA) compared with four-factor prothrombin complex concentrate (4F-PCC) for the reversal of factor Xa inhibitor-associated intracranial hemorrhage (ICH). Our aim was to describe a compilation of the information available in the literature to date. Methods: PubMed, Embase, Web of Science (Clarivate Analytics) and the Cochrane Central Register of Controlled Trials were searched until December 2023. Following the "Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)" guidelines, our systematic literature review included studies that were retrospective in design and evaluated both drugs to control bleeding and complications (death and thromboembolic events). Two researchers re-examined the studies for relevance, extracted the data and assessed the risk of bias. No meta-analyses were performed for the results. Results: In this limited patient sample, we found no differences between published articles in terms of neuroimaging stability or thrombotic events. However, some studies show significant differences in mortality, suggesting that one of the AAs may be superior to 4F-PCC. Conclusions: Our qualitative analysis shows that AA has a better efficacy profile compared with 4F-PCC. However, further studies monitoring these patients and a multicenter collaborative network dedicated to this topic are needed.

A small-molecule hemostatic agent for the reversal of direct oral anticoagulant-induced bleeding

Background

The bleeding risk associated with direct oral anticoagulants (DOACs) remains a major concern, and rapid reversal of anticoagulant activity may be required. Although specific and nonspecific hemostatic biotherapies are available, there is a need for small-molecule DOAC reversal agents that are simple and cost-effective to produce, store, and administer.

Objectives

To identify and characterize a small molecule with procoagulant activity as a DOAC reversal agent.

Methods

We sought to identify a small procoagulant molecule by screening a chemical library with a plasma clotting assay. The selected molecule was assessed for its procoagulant properties and its ability to reverse the effects of the DOACs in a thrombin generation assay. Its activity as a DOAC reversal agent was also evaluated in a tail-clip bleeding assay in mice.

Results

The hemostatic molecule (HeMo) dose-dependently promoted thrombin generation in plasma, with dose values effective in producing half-maximum response ranging between 3 and 5 μM, depending on the thrombin generation assay parameter considered. HeMo also restored impaired thrombin generation in DOAC-spiked plasma and reversed DOAC activity in the mouse bleeding model. HeMo significantly reduced apixaban-induced bleeding from 709 to 65 μL (vs 43 μL in controls; P < .01) and dabigatran-induced bleeding from 989 to 155 μL (vs 126 μL in controls; P < .01).

Conclusion

HeMo is a small-molecule procoagulant that can counterbalance hemostatic disruption by a thrombin inhibitor (dabigatran) or factor Xa inhibitors (apixaban and rivaroxaban). The compound's effective clot formation and versatility make it a possible option for managing the inherent hemorrhagic risk during DOAC therapy.

Clinical Pathways and Outcomes of Andexanet Alfa Administration for the Reversal of Critical Bleeding in Patients on Oral Direct Factor Xa Inhibitors

Background  Andexanet is U.S. Food and Drug Administration (FDA) approved for the reversal of critical bleeding from factor Xa inhibitors and off-label for surgical reversal. Data are lacking on andexanet administration processes. Methods  We retrospectively studied patients at a 23-hospital system who received andexanet from November 2019 to March 2023. Abstractors coded demographics, comorbidities, anticoagulant use, andexanet indication, and process times. The primary outcome was presentation-to-andexanet time; diagnosis, ordering, and administration times were calculated. Secondary outcomes included in-hospital postandexanet major thromboembolism/bleeding and mortality. Results  In total, 141 patients were analyzed. Andexanet indications were predominantly neurologic bleeding (85.8%). Twenty-four patients (17.0%) were transferred from nontertiary/academic centers to tertiary/academic centers. The median presentation-to-administration time was 192.5 minutes (interquartile range [IQR]: 108.0-337.0 minutes). Components were as follows: 72.5 minutes (IQR: 39.0-137.5 minutes) for bleeding diagnosis; 35.5 minutes (IQR: 0-96.5 minutes) for andexanet ordering; and 53.0 minutes (IQR: 38.5-78.5 minutes) for administration, which was longer at tertiary/academic hospitals (ratio 1.5, 95% confidence interval [CI]: 1.2-2.0, p  = 0.002). Gastrointestinal or other critical bleeding (ratio 2.59, 95% CI: 1.67-4.02, p  < 0.001), and tertiary/academic center treatment (ratio 1.58, 95% CI: 1.15-2.18, p  = 0.005), were associated with increased time. Major thromboembolism, bleeding, and mortality occurred in 10.6, 12.0, and 22.9% of patients, respectively. Conclusions  In our cohort, the median presentation-to-administration time was over 3 hours. Cumulative times were longer at tertiary/academic hospitals and for gastrointestinal/other bleeding. Postandexanet major thromboembolism/bleeding occurred more at tertiary/academic hospitals, possibly related to transfers. Prospective studies may elucidate clinical decision-making bottlenecks.

Is reversal of anticoagulants necessary in neurologically intact traumatic intracranial hemorrhage?

INTRODUCTION

Falls are the leading cause of injury in older individuals, with intracranial hemorrhage (ICH) being a common complication. Anticoagulants, such as vitamin K antagonist and direct oral anticoagulants, are increasingly utilized, and clinicians may question the necessity of reversal in patients with minor ICH, especially in the setting of increased risk of adverse events. This study aimed to identify a population of patients with minor traumatic ICH at low risk for poor-neurologic status where anticoagulant reversal may not improve outcomes.

METHODS

This retrospective cohort study utilized data accessed from 35 trauma centers from 2018 to 2021. Patients included had a preinjury anticoagulant regimen, ICH due to blunt trauma, Glasgow Coma Scale score of 15, an Abbreviated Injury Scale (AIS) head score from 2 to 4, and an AIS of ≤1 for non-head regions within 24 h of hospital arrival. Patients were excluded if they required an emergent neurosurgical procedure or were on a preinjury purinergic-P2 receptor-12 protein (P2Y12) inhibitor. The primary outcome was the rate of in-hospital mortality or hospice.

RESULTS

There were 654 patients on preinjury anticoagulation who were included with a minor traumatic ICH without neurologic deficits. Overall, 263 patients were reversed and 391 were not reversed. Twelve (4.6%) patients with in-hospital mortality or hospice were reversed compared with 19 (4.91%) patients who were not reversed (p = 0.861). A composite of hospital complications occurred in 21 (8%) reversed patients and 34 (8.7%) not reversed patients (p = 0.748). The average intensive care unit length of stay was 1.4 ± 3.4 days in the reversed group and 1.1 ± 1.8 days in the not reversed group (p = 0.069).

CONCLUSION

This study found no difference in hospital outcomes between patients with minor traumatic ICH on oral anticoagulants who were neurologically intact that were reversed versus those who were not reversed. Further studies should continue to define the subset of traumatic ICH patients who may not require reversal of anticoagulation.

Mortality after major bleeding in Asian atrial fibrillation patients receiving different direct oral anticoagulants: a nationwide, propensity score study

In this research, we assessed mortality after major bleeding events in atrial fibrillation (AF) patients taking four direct oral anticoagulants (DOACs). Drawing data from the Taiwan National Health Insurance Research Database between 2016 and 2019, we focused on AF patients on DOACs who had major bleeding episodes. Using propensity score stabilized weighting, we established four comparable pseudo-DOAC groups. Among 2770 patients (460 dabigatran, 1322 rivaroxaban, 548 apixaban, 440 edoxaban), 85.3% were prescribed low-dose regimens. The 7-day mortality rate was 9.0%, surging to 16.0% by the 30th day. Compared with dabigatran, there was a distinct divergence in 7-day mortality of factor Xa inhibitors (p = 0.012), with hazard ratios of 1.83 (95% CI 1.11-3.00, p = 0.017) for rivaroxaban, 2.13 (95% CI 1.23-3.66, p = 0.007) for apixaban, and 2.41 (95% CI 1.39-4.19, p = 0.002) for edoxaban. This pattern remained consistent when analyzing the subgroup that received lower dosages of DOACs. In conclusion, factor Xa inhibitors were associated with a significantly higher risk of 7-day mortality following major bleeding events than dabigatran among AF patients.

Use of Andexanet Alfa for Factor Xa Inhibitor Reversal in US Verified Trauma Centers: A National Survey

Direct oral factor Xa inhibitors are replacing vitamin K-dependent antagonists as anticoagulation treatment in many clinical scenarios. Trauma centers are noting an increase in patients presenting on these medications. The 2018 Food and Drug Administration approval of andexanet alfa provides an alternative anticoagulation reversal. Barriers may limit utilization of new medications including a lack of grade 1A evidence supporting the use of prothrombin complex concentrate (PCC) versus andexanet alfa and cost. To evaluate barriers of andexanet alfa utilization by trauma surgeons, a 15-question survey was conducted. There was a 9% completion rate (n = 89). The results revealed 23.5% would choose andexanet alfa as first-line treatment in children, and 25.8% as first-line treatment in adults. The majority of respondents, 64.7% and 67.4%, would use PCC preferentially in children and adults, respectively. Respondents indicated that cost burden was an overriding factor (76.3%); 42.4% cited lack of high-level efficacy data of andexanet alfa for reversal of factor Xa inhibitors. Additional double-blinded multi-institutional randomized controlled trials comparing 4F-PCC and andexanet alfa for factor Xa inhibitor reversal are needed to support efficacy especially with the increased cost associated.

Definition of factor Xa inhibitor-related, life-threatening gastrointestinal bleeding and guidance on when to use reversal therapy: A Delphi panel

Objective

To define and contextualize life-threatening gastrointestinal (GI) bleeding in the setting of factor Xa (FXa) inhibitor therapy and to derive a consensus-based, clinically oriented approach to the administration of FXa inhibitor reversal therapy.

Methods

We convened an expert panel of clinicians representing specialties in emergency medicine, gastroenterology, vascular medicine, and trauma surgery. Consensus was reached among the clinician panelists using the Delphi technique, which consisted of 2 survey questionnaires followed by virtual, real-time consensus-building exercises.

Results

Hypovolemia and hemodynamic instability were considered the most important clinical signs of FXa inhibitor-related, life-threatening GI bleeds. Clinician panelists agreed that potentially life-threatening GI bleeding should be determined on the basis of hemodynamic instability, signs of shock, individual patient characteristics, and clinical judgment. Last, the panel agreed that all patients with life-threatening, FXa inhibitor-associated GI bleeding should be considered for FXa inhibitor reversal therapy; the decision to reverse FXa inhibition should be individualized, weighing the risks and benefits of reversal; and when reversal is elected, therapy should be administered within 1 h after initial emergency department evaluation, when possible.

Conclusions

Consensus-based definitions of life-threatening GI bleeding and approaches to FXa inhibitor reversal centered on hemodynamic instability, signs of shock, individual patient characteristics, and clinical judgment. The results from this Delphi panel may inform clinical decision-making for the treatment of patients experiencing GI bleeding associated with FXa inhibitor use in the emergency department setting.

Clinical Relevance of Preclinical and Clinical Studies of Four-Factor Prothrombin Complex Concentrate for Treatment of Bleeding Related to Direct Oral Anticoagulants

Direct oral anticoagulants (DOACs) are widely used for the prevention and treatment of venous thromboembolism and stroke. When emergency reversal of DOAC-related anticoagulation is required, specific DOAC reversal agents are recommended, including idarucizumab for dabigatran reversal and andexanet alfa for apixaban and rivaroxaban reversal. However, specific reversal agents are not always available, andexanet alfa has not been approved for urgent surgery, and clinicians need to know the patient's anticoagulant medication before administering these treatments. Four-factor prothrombin complex concentrates (4F-PCCs) are recognized as nonspecific, alternative hemostatic agents for treatment of DOAC-related bleeding. Evidence from preclinical and clinical studies shows that they may reduce the anticoagulant effects of DOACs and may help control DOAC-related bleeding. However, randomized controlled trials are lacking, and most data are from retrospective or single-arm prospective studies in bleeding associated with activated factor X inhibitors. There are no clinical data showing the efficacy of 4F-PCC for the treatment of bleeding in dabigatran-treated patients. This review focuses on the current evidence of 4F-PCC use in controlling bleeding associated with DOACs and provides an expert opinion on the relevance of these data for clinical practice. The current treatment landscape, unmet needs, and future directions are also discussed.

Prothrombin Complex Concentrate Utilization in Children's Hospitals

Prothrombin complex concentrates (PCCs) are used to manage bleeding in critically ill children. We performed a repeat cross-sectional study using the Pediatric Health Information System registry to describe PCC utilization in the U.S. children's hospitals over time and determine the relationship between PCC use and specific risk factors for bleeding. We included children < 18 years who received three-factor or four-factor PCC during hospital admission between January 2015 and December 2020 to describe the association between PCC therapy, anticoagulation therapies, and inherited or acquired bleeding diatheses. PCC use steadily increased over the 6-year study period (from 1.3 to 4.6 per 10,000 encounters). Patients exhibited a high degree of critical illness, with 85.0% requiring intensive care unit admission and a mortality rate of 25.8%. PCCs were used in a primarily emergent or urgent fashion (32.6 and 39.3%, respectively) and more frequently in surgical cases (79.0% surgical vs. 21.0% medical). Coding analysis suggested a low rate of chronic anticoagulant use which was supported by review of concomitant anticoagulant medications. PCC use is increasing in critically ill children and does not correlate with specific anticoagulant therapy use or other bleeding risk factors. These findings suggest PCC use is not limited to vitamin K antagonist reversal. Indications, efficacy, and safety of PCC therapy in children require further study.

Lower mortality with andexanet alfa vs 4-factor prothrombin complex concentrate for factor Xa inhibitor-related major bleeding in a U.S. hospital-based observational study

Background

Well-designed studies with sufficient sample size comparing andexanet alfa vs 4-factor prothrombin complex concentrate (4F-PCC) in routine clinical practice to evaluate clinical outcomes are limited.

Objectives

To compare in-hospital mortality in patients hospitalized with rivaroxaban- or apixaban-related major bleeding who were treated with andexanet alfa or 4F-PCC.

Methods

An observational cohort study (ClinicalTrials.gov identifier: NCT05548777) was conducted using electronic health records between May 2018 and September 2022 from 354 U.S. hospitals. Inclusion criteria were age ≥18 years, inpatient admission with diagnosis code D68.32 (bleeding due to extrinsic anticoagulation), a record of use of the factor Xa inhibitors rivaroxaban or apixaban, andexanet alfa or 4F-PCC treatment during index hospitalization, and a documented discharge disposition. Multivariable logistic regression on in-hospital mortality with andexanet alfa vs 4F-PCC was performed. The robustness of the results was assessed via a supportive propensity score-weighted logistic regression.

Results

The analysis included 4395 patients (andexanet alfa, n = 2122; 4F-PCC, n = 2273). There were 1328 patients with intracranial hemorrhage (ICH), 2567 with gastrointestinal (GI) bleeds, and 500 with critical compartment or other bleed types. In the multivariable analysis, odds of in-hospital mortality were 50% lower for andexanet alfa vs 4F-PCC (odds ratio [OR], 0.50; 95% CI, 0.39-0.65; P < .01) and were consistent for both ICH (OR, 0.55; [0.39-0.76]; P < .01) and GI bleeds (OR, 0.49 [0.29-0.81]; P = .01). Similar results were obtained from the supporting propensity score-weighted logistic regression analyses.

Conclusion

In this large observational study, treatment with andexanet alfa in patients hospitalized with rivaroxaban- or apixaban-related major bleeds was associated with 50% lower odds of in-hospital mortality than 4F-PCC. The magnitude of the risk reduction was similar in ICH and GI bleeds.

Recommendations for the use of andexanet alfa in the management of bleeding in patients on oral factor Xa inhibitors in Switzerland: Guideline from the Working Party Hemostasis of the Swiss Society of Hematology

Anticoagulants are essential in preventing and treating thrombosis. Unfortunately, their use is accompanied by an enhanced risk of bleeding. Since the introduction of direct oral anticoagulants (DOACs), the risk of major bleeding has been reduced but not eliminated. Major bleeding events related to the use of factor Xa inhibitors can be challenging to manage. In recent years, four-factor prothrombin complex concentrates have been used in patients with severe bleeding taking oral direct factor Xa inhibitors (apixaban, edoxaban and rivaroxaban). Andexanet alfa (OndexxyaTM, AstraZeneca AG) is a specially designed recombinant version of human factor Xa that acts as a decoy receptor to reverse the effects of factor Xa inhibitors. Since 2 December 2020, andexanet alfa has been used in Switzerland for adult patients receiving apixaban or rivaroxaban when reversal of anticoagulation is required because of life-threatening or uncontrolled bleeding. However, the use of andexanet alfa remains a challenge owing to its cost, the reported thrombotic complications and the fact that its efficacy mainly relates to intracranial haemorrhage. Moreover, the use of nonspecific reversal agents together with andexanet alfa is controversial. The present recommendations on the use of andexanet alfa in the management of bleeding in patients on factor Xa inhibitors in Switzerland were developed by a group of Swiss experts from the Working Party Hemostasis of the Swiss Society of Hematology. These recommendations aim to provide support to clinicians in their decision-making in the management of patients with major bleeding receiving factor Xa inhibitors.

Propensity matched analysis examining the effect of passive reversal of direct oral anticoagulants on blood loss and the need for transfusions among traumatic geriatric hip fractures

BACKGROUND

Reversal of direct oral anticoagulants (DOACs) is currently recommended prior to emergent surgery, such as surgical intervention for traumatic geriatric hip fractures. However, reversal methods are expensive and timely, often delaying surgical intervention, which is a predictor of outcomes. The study objective was to examine the effect of DOAC reversal on blood loss and transfusions among geriatric patients with hip fractures.

METHODS

This retrospective propensity-matched study across six level I trauma centers included geriatric patients on DOACs with isolated fragility hip fractures requiring surgical intervention (2014-2017). Outcomes included: intraoperative blood loss, intraoperative pRBCs, and hospital length of stay (HLOS).

RESULTS

After matching there were 62 patients (31 reversed, 31 not reversed), 29 patients were not matched. The only reversal method utilized was passive reversal (waiting ≥ 24 hours for elimination). Passively reversed patients had a longer time to surgery (mean, 43 vs. 18 hours, p < 0.01). Most patients (92%) had blood loss (90% passively reversed, 94% not reversed); the median volume of blood loss was 100 mL for both those groups, p = 0.97. Thirteen percent had pRBCs transfused (13% passively reversed and 13% not reversed); the median volume of pRBCs transfused was 525 mL for those passively reversed and 314 mL for those not reversed, p = 0.52. The mean HLOS was significantly longer for those passively reversed (7 vs. 5 days, p = 0.001).

CONCLUSIONS

Passive DOAC reversal for geriatric patients with isolated hip fracture requiring surgery may be contributing to delayed surgery and an increased HLOS without having a significant effect on blood loss or transfusions. These data suggest that passive DOAC reversal may not be necessary prior to surgical repair of isolated hip fracture.

Real-world clinical outcomes among US Veterans with oral factor xa inhibitor-related major bleeding treated with andexanet alfa or 4-factor prothrombin complex concentrate

Oral factor Xa (FXa) inhibitors significantly reduce incidence of stroke and thromboembolic events in patients with atrial fibrillation or venous thromboembolism. Due to various factors and the lack of a randomized controlled trial comparing andexanet alfa to usual care, non-specific replacement agents including 4 F-PCC are still used off-label for FXa inhibitor bleed management. Clinical and mortality data were extracted from the inpatient medical data and Veteran Affairs (VA) vital status files over the time of March 2014 through December 2020. Propensity score-weighted models were used for this retrospective cohort study using data from the Veterans Affairs Informatics and Computing Infrastructure (VINCI). The study included 255 patients (85-andexanet alfa and 170-4 F-PCC) exposed to an oral factor Xa inhibitor and hospitalized with an acute major, gastrointestinal (GI), intracranial (ICH) or other bleed. In-hospital mortality was significantly lower in the andexanet alfa cohort compared to the 4 F-PCC cohort (10.6% vs. 25.3%, p = 0.01). Propensity score-weighted Cox models reveal a 69% lower hazard of in-hospital mortality for those treated with andexanet alfa (HR 0.31, 95% CI 0.14-0.71) compared to those treated with 4 F-PCC. Additionally, those treated with andexanet alfa had a lower 30-day mortality rate and lower 30-day hazard of mortality in the weighted Cox model (20.0% vs. 32.4%, p = 0.055; HR 0.54, 95% CI 0.30-0.98) compared to those treated with 4 F-PCC. Among 255 US veterans with major bleeding in the presence of an oral factor Xa inhibitor, treatment with andexanet alfa was associated with lower in-hospital and 30-day mortality than treatment with 4 F-PCC.

A review of emerging factor XI inhibitors

INTRODUCTION

Whilst the introduction of direct oral anticoagulants (DOACs) has improved the prevention of thromboembolic events, there is still a need for safer anticoagulants. This is particularly so, for specific populations of patients, such as those with an increased bleeding risk or those with severely reduced kidney function. People with Factor XI (FXI) deficiency are at reduced risk of thromboembolic events, without an increased risk of spontaneous bleeding. FXI inhibition, therefore, presents the ideal target for novel anticoagulants.

AREAS COVERED

In this review, we provide an overview of the currently available anticoagulants and the emerging FXIa inhibitors in clinical trials. The need for availability of novel anticoagulants and the potential issues that will hinder the development and marketing of factor XIa inhibitors is also discussed.

EXPERT OPINION

Evidence suggests that FXI inhibition presents a promising drug target for novel anticoagulation therapies. The FXIa inhibitors in development have advantages over DOACs with lower renal clearance and long half-lives. Overall, FXI inhibition presents a promising target, it is likely that the clinical use of FXIa inhibitors is on the horizon.

Pharmacist authors of emergency medicine organization work products pertaining to pharmacotherapy

PURPOSE

Despite the expertise that emergency medicine (EM) pharmacists bring to multidisciplinary teams in the emergency department (ED) setting, they are not commonly present on writing groups for guidelines, policies, or task forces pertaining to EM pharmacotherapy. The purpose of this article is to quantify EM pharmacist involvement on author bylines of guidelines, position statements, and other official documents that specifically encompass EM pharmacotherapy.

METHODS

Official work products released between January 1, 2010, and May 1, 2021, were collected from the American College of Emergency Physicians (ACEP), Society for Academic Emergency Medicine (SAEM), and American Academy of Emergency Medicine (AAEM) and the table of contents of the following journals: Annals of Emergency Medicine, Academic Emergency Medicine, and Journal of Emergency Medicine. A modified Delphi approach was used to gain consensus amongst the authors on which work products to include in the initial review and which works pertained to pharmacotherapy. The primary endpoint was the percentage of pharmacists listed as authors on EM work products pertaining to pharmacotherapy.

RESULTS

Overall, 76 EM work products were identified. Forty-seven work products with a total of 248 authors contained at least 1 recommendation pertaining to pharmacotherapy. Of these 47 EM work products, 23 (49%) were from AAEM, 16 (34%) were from Annals of Emergency Medicine (published on behalf of ACEP), 5 (11%) were from Journal of Emergency Medicine (published on behalf of AAEM), and 3 (6%) were from SAEM. The median number of authors per work product was 4. There were 5 pharmacists listed on work products (2% of the total of 248 authors). Additionally, there were 9 nonpharmacist/nonphysician authors (4% of the total).

CONCLUSION

Pharmacist inclusion on author lists of recently published EM work products pertaining to pharmacotherapy is extremely low. Given their unique knowledge pertaining to EM pharmacotherapy, an effort should be made to increase inclusion of pharmacists as authors of EM work products with recommendations that pertain to pharmacotherapy.

Direct Oral Anticoagulant Reversal in the Pediatric Emergency Department

ABSTRACT

Direct oral anticoagulants have been used in the adult population for years and are being used more frequently in pediatrics. Direct oral anticoagulants are chosen preferentially because they do not require close outpatient monitoring, have an equal or better safety profile, and are easy for patients to take. Warfarin is the previous, more commonly used oral anticoagulant and acts as a vitamin K antagonist. Direct oral anticoagulants mechanism of action is different in that they directly inhibit part of the coagulation cascade accomplishing the same end goal. Given their differing mechanisms, they require alternate medications for proper reversal when concerned about overdose of life-threatening bleeds. This review will outline the most commonly used direct oral anticoagulants in pediatric populations and the supporting (mainly adult) data available for proper reversal of these medications in times of need.

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.

Dosing Medications for Coagulopathy Reversal in Patients with Extreme Obesity

BACKGROUND

The reversal of anticoagulant or antiplatelet medications is a priority in the management of patients with severe injury with the goal of minimizing further bleeding without thrombotic complications. There are few studies, however, evaluating the dosing of reversal agents in the setting of trauma specific to patients with extreme obesity. Nevertheless, clinicians must still make decisions, balancing concerns of ongoing bleeding with excessive thrombosis.

OBJECTIVES

We describe the literature pertaining to dosing of medications used for the reversal of both drug-induced and trauma-related coagulopathy with the intent of providing a framework for clinicians to make dosing decisions in this challenging population.

DISCUSSION

Obesity is known to impact both the volume of distribution and the clearance of medications, but these changes are not usually linear with size nor are they uniform across drugs. Current strategies for dosing reversal agents in obesity include a capped dose (e.g., prothrombin complex concentrates), fixed dosages (e.g., andexanet alfa, idarucizumab, and tranexamic acid), and weight-based dosing (e.g., desmopressin). Extreme obesity, however, was not highly prevalent in the studies that have validated these dosing strategies. In fact, many of the clinical studies fail to report the average weight of the patients included.

CONCLUSION

Future studies should make efforts to increase reporting of patients with obesity included in clinical trials along with results stratified by weight class. In the meantime, doses listed in product labels should be used. Desmopressin should be dosed using either ideal body weight or a dose-capping strategy.

Performance of a Qualitative Point-of-Care Strip Test to Detect DOAC Exposure at the Emergency Department: A Cohort-Type Cross-Sectional Diagnostic Accuracy Study

An accurate point-of-care test for detecting effective anticoagulation by direct oral anticoagulants (DOACs) in emergencies is an unmet need. We investigated the accuracy of a urinary qualitative strip test (DOAC Dipstick) to detect relevant DOAC exposure in patients who presented to an emergency department. In this prospective single-center cohort-type cross-sectional study, adults on DOAC treatment were enrolled. We assessed clinical sensitivity and specificity of DOAC Dipstick factor Xa and thrombin inhibitor pads to detect DOAC plasma levels ≥30 ng/mL using urine samples as the testing matrix. Liquid chromatography coupled with tandem-mass spectrometry was used as the reference standard method for plasma and urine measurement of DOAC concentrations. Of 293 patients enrolled, 265 patients were included in the analysis, of whom 92 were treated with rivaroxaban, 65 with apixaban, 77 with edoxaban, and 31 with dabigatran. The clinical sensitivity and specificity of the dipstick on urine samples to detect ≥30 ng/mL dabigatran plasma levels were 100% (95% confidence interval [CI]: 87–100%) and 98% (95% CI: 95–99%), respectively. The sensitivity and specificity of the dipstick to detect ≥30 ng/mL factor Xa inhibitor plasma levels were 97% (95% CI: 94–99%) and 69% (95% CI: 56–79%), respectively. The DOAC Dipstick sensitively identified effective thrombin and factor Xa inhibition in a real-world cohort of patients presenting at an emergency department. Therefore, the dipstick might provide a valuable test to detect relevant DOAC exposure in emergencies, although further studies will be needed to confirm these findings.

Andexanet alfa versus four-factor prothrombin complex concentrate for the reversal of apixaban- or rivaroxaban-associated intracranial hemorrhage: a propensity score-overlap weighted analysis

BACKGROUND

Andexanet alfa is approved (FDA "accelerated approval"; EMA "conditional approval") as the first specific reversal agent for factor Xa (FXa) inhibitor-associated uncontrolled or life-threatening bleeding. Four-factor prothrombin complex concentrates (4F-PCC) are commonly used as an off-label, non-specific, factor replacement approach to manage FXa inhibitor-associated life-threatening bleeding. We evaluated the effectiveness and safety of andexanet alfa versus 4F-PCC for management of apixaban- or rivaroxaban-associated intracranial hemorrhage (ICH).

METHODS

This two-cohort comparison study included andexanet alfa patients enrolled at US hospitals from 4/2015 to 3/2020 in the prospective, single-arm ANNEXA-4 study and a synthetic control arm of 4F-PCC patients admitted within a US healthcare system from 12/2016 to 8/2020. Adults with radiographically confirmed ICH who took their last dose of apixaban or rivaroxaban < 24 h prior to the bleed were included. Patients with a Glasgow Coma Scale (GCS) score < 7, hematoma volume > 60 mL, or planned surgery within 12 h were excluded. Outcomes were hemostatic effectiveness from index to repeat scan, mortality within 30 days, and thrombotic events within five days. Odds ratios (ORs) with 95% confidence intervals (CI) were calculated using propensity score-overlap weighted logistic regression.

RESULTS

The study included 107 andexanet alfa (96.6% low dose) and 95 4F-PCC patients (79.3% receiving a 25 unit/kg dose). After propensity score-overlap weighting, mean age was 79 years, GCS was 14, time from initial scan to reversal initiation was 2.3 h, and time from reversal to repeat scan was 12.2 h in both arms. Atrial fibrillation was present in 86% of patients. Most ICHs were single compartment (78%), trauma-related (61%), and involved the intracerebral and/or intraventricular space(s) (53%). ICH size was ≥ 10 mL in volume (intracerebral and/or ventricular) or ≥ 10 mm in thickness (subdural or subarachnoid) in 22% of patients and infratentorial in 15%. Andexanet alfa was associated with greater odds of achieving hemostatic effectiveness (85.8% vs. 68.1%; OR 2.73; 95% CI 1.16-6.42) and decreased odds of mortality (7.9% vs. 19.6%; OR 0.36; 95% CI 0.13-0.98) versus 4F-PCC. Two thrombotic events occurred with andexanet alfa and none with 4F-PCC.

CONCLUSIONS

In this indirect comparison of patients with an apixaban- or rivaroxaban-associated ICH, andexanet alfa was associated with better hemostatic effectiveness and improved survival compared to 4F-PCC. Trial registration NCT02329327; registration date: December 31, 2014.

Andexanet alfa after 4-factor PCC administration for intracranial hemorrhage: a case series

The ongoing controversy regarding optimal reversal agent for factor Xa-inhibitors is mainly due to lack of comparative data of andexanet alfa (AA) to 4-factor prothrombin complex concentrate (4F-PCC), institutional formulary restrictions, and navigation of clinical scenarios involving patients clinically worsen despite initial reversal efforts. The combination use of 4F-PCC and AA has not been evaluated in clinical trials and the outcomes of such patients with FXA-inhibitor associated intracranial hemorrhage (ICH) are unknown. A total of five patients, including four outside hospital transfers, received 4F-PCC prior to AA for FXa-inhibitor associated ICH (n = 3 apixaban, n = 2 rivaroxaban; n = 4 ICH, n = 1 TBI). The doses of 4F-PCC ranged from 25 to 60 units/kg and were administered within a range of 1.5-4.2 h prior to AA. One patient required surgical intervention with craniotomy and three patients underwent external ventricular drain placement. Two of the five patients developed an ischemic or thromboembolic complication within one week from 4F-PCC and AA administration. This case series discusses multiple unique patient cases in which 4F-PCC and AA were both administered for FXa-inhibitor associated ICH. The results highlight the potentially increased thrombotic risk associated with combination use. Ongoing post-marketing data collection of real patient case scenarios are essential to the establishment of consensus guidelines on how to prioritize initial reversal efforts and manage these patients during the course of their bleed.

Thirty-day mortality with andexanet alfa compared with prothrombin complex concentrate therapy for life-threatening direct oral anticoagulant-related bleeding

Objective

Compare 30-day mortality among patients receiving the specific reversal agent andexanet alfa versus replacement prothrombin complex concentrate (PCC) in the management of direct-acting oral anticoagulant (DOAC)-related bleeds.

Methods

Two patient-level datasets were used: ANNEXA-4, a prospective, single-arm trial of patients taking apixaban or rivaroxaban who received andexanet alfa and ORANGE, a prospective, observational study of anticoagulated patients in UK hospitals, some of whom received PCC. Patients were propensity score matched based on demographic and clinical characteristics. Subgroup analyses were performed by bleed type (intracranial hemorrhage [ICH], gastrointestinal [GI], other). Relative risk (RR) of all-cause 30-day mortality was calculated.

Results

322 ANNEXA-4 patients treated with andexanet alfa (mean age = 77.7 years; 64.9% ICH) were matched with 88 ORANGE patients treated with PCC (mean age = 74.9 years, 67.1% ICH). Adjusted 30-day mortality for patients treated with andexanet alfa (14.6%) was lower than patients treated with PCC (34.1%; RR, 0.43; 95% CI, 0.29-0.63). In the ICH subgroup, patients treated with andexanet alfa had lower mortality (15.3%) than patients treated with PCC (48.9%; RR, 0.31; 95% CI, 0.20-0.48). Mortality risk was lowest for patients in the GI subgroup but did not differ significantly by treatment (12.2% for andexanet alfa vs 25.0% for PCC; RR, 0.49; 95% CI, 0.21-1.16).

Conclusions

In this propensity score-matched comparison across 2 independent datasets, adjusted 30-day mortality rates were lower for patients treated with andexanet alfa than in matched patients receiving PCC. This indirect comparison was limited in that it could not account for several highly predictive variables including GCS score, hematoma volume, and expected survival. Further research is warranted to confirm the mortality differences between reversal/replacement agents for DOAC-related bleeding.

Four-factor prothrombin complex concentrate plus andexanet alfa for reversal of factor Xa inhibitor-associated bleeding: Case series

DISCLAIMER

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PURPOSE

To manage factor Xa (FXa) inhibitor-associated bleeding, andexanet alfa or 4-factor prothrombin concentrate (4F-PCC) has been used to restore hemostasis. However, literature on the outcomes for patients who received both andexanet alfa and 4F-PCC is limited.

SUMMARY

We report a case series of 5 patients who received andexanet alfa plus 4F-PCC for reversal of FXa inhibitor-associated bleeding. Patients were included in this case series if they received both andexanet alfa and 4F-PCC for reversal of FXa inhibitor-associated bleeding. They were followed to either discharge or death, and in-hospital complications related to concurrent use of andexanet alfa and 4F-PCC were documented. We report an incidence of thromboembolism of 40% (2 of 5 cases) and an in-hospital mortality rate of 60% (3 of 5 cases). Taking these cases together with those in the existing literature, we found a total of 23 reported cases of safety outcomes with andexanet alfa plus 4F-PCC. The overall incidence of thromboembolism was 35% (8 of 23 cases).

CONCLUSION

This case series adds to the limited literature describing the outcomes for patients receiving andexanet alfa plus 4F-PCC. We encourage other institutions to report safety data on administering both agents.

Cost-effectiveness of andexanet alfa versus four-factor prothrombin complex concentrate for the treatment of oral factor Xa inhibitor-related intracranial hemorrhage in the US

AIM

To conduct a cost-effectiveness analysis (CEA) on the use of andexanet alfa for the treatment of factor Xa inhibitor-related intracranial hemorrhage (ICH) from the US third-party payer and societal perspectives.

METHODS

CEA compared andexanet alfa to prothrombin complex concentrate for the treatment of patients receiving factor Xa inhibitors admitted to hospital inpatient care with an ICH. The model comprised two linked phases. Phase 1 utilized a decision tree to model the acute treatment phase (admission of a patient with ICH into intensive care for the first 30 days). Phase 2 modeled long-term costs and outcomes using three linked Markov models comprising the six health states defined by the modified Rankin score.

RESULTS

The analysis showed that the strategy of using andexanet alfa for the treatment of factor Xa inhibitor-related ICH is cost-effective, with incremental cost-effectiveness per quality-adjusted life-year gained of $35,872 from a third-party payer perspective and $40,997 from a societal perspective over 20 years.

LIMITATIONS

(1) Absence of head-to-head trials comparing therapies included in the economic model, (2) lack of comparative long-term data on treatment efficacy, and (3) bias resulting from the study designs of published literature.

CONCLUSION

Given these results, the use of andexanet alfa for the reversal of anticoagulation in patients with factor Xa inhibitor-related ICH may improve quality of life and is likely to be cost-effective in a US context.

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.

Hematoma Expansion and Clinical Outcomes in Patients With Factor-Xa Inhibitor-Related Atraumatic Intracerebral Hemorrhage Treated Within the ANNEXA-4 Trial Versus Real-World Usual Care

BACKGROUND AND PURPOSE

It is unestablished whether andexanet alfa, compared with guideline-based usual care including prothrombin complex concentrates, is associated with reduced hematoma expansion (HE) and mortality in patients with factor-Xa inhibitor-related intracerebral hemorrhage (ICH). We compared the occurrence of HE and clinical outcomes in patients treated either with andexanet alfa or with usual care during the acute phase of factor-Xa inhibitor-related ICH.

METHODS

Data were extracted from the multicenter, prospective, single-arm ANNEXA-4 trial (Andexanet Alfa, a Novel Antidote to the Anticoagulation Effects of Factor Xa Inhibitors) and a multicenter observational cohort study, RETRACE-II (German-Wide Multicenter Analysis of Oral Anticoagulant-Associated Intracerebral Hemorrhage - Part Two). HE was based on computed tomography scans performed within 36 hours from baseline imaging. Inverse probability of treatment weighting was performed to adjust for baseline comorbidities and ICH severity. Patients presenting with atraumatic ICH while receiving apixaban or rivaroxaban within 18 hours of admission were included. Patients with secondary ICH or not fulfilling the inclusion criteria for the ANNEXA-4 trial were excluded. We compared ANNEXA-4 patients, who received andexanet alfa for hemostatic treatment, with RETRACE-II patients who were treated with usual care, primarily administration of prothrombin complex concentrates. Primary outcome was rate of HE defined as relative increase of ≥35%. Secondary outcomes comprised mean absolute change in hematoma volume, as well as in-hospital mortality and functional outcome.

RESULTS

Overall, 182 patients with factor-Xa inhibitor-related ICH (85 receiving andexanet alfa versus 97 receiving usual care) were selected for analysis. There were no relevant differences regarding demographic or clinical characteristics between both groups. HE occurred in 11 of 80 (14%) andexanet alfa patients compared with 21 of 67 (36%) usual care patients (adjusted relative risk, 0.40 [95% CI, 0.20-0.78]; P=0.005), with a reduction in mean overall hematoma volume change of 7 mL. There were no statistically significant differences among in-hospital mortality or functional outcomes. Sensitivity analysis including only usual care patients receiving prothrombin complex concentrates demonstrated consistent results.

CONCLUSIONS

As compared with usual care, andexanet alfa was associated with a lower rate of HE in atraumatic factor-Xa inhibitor-related ICH, however, without translating into significantly improved clinical outcomes. A comparative trial is needed to confirm the benefit on limiting HE and to explore clinical outcomes across patient subgroups and by time to treatment.

Review of Prothrombin Complex Concentrates Use in Apixaban and Rivaroxaban Associated Intracranial Hemorrhages

STUDY OBJECTIVE

Summarize the studies evaluating the use of 4-factor prothrombin complex concentrates in the management of apixaban and rivaroxaban associated intracranial hemorrhages.

METHODS

A PubMed literature search was conducted for articles published between 2013 and 2020 which contained the following terms in their title: (1) apixaban, rivaroxaban, or factor Xa inhibitor*, and (2) prothrombin complex concentrate*.

RESULTS

Eighteen observational studies were included. When a ∼25 units/kg (range: 25-26.9 units/kg) non-activated 4 factor prothrombin complex concentrate dose was administered, the hemostatic effectiveness rates were ≥ 79% in 2/4 studies that utilized the Sarode et al criteria, in comparison to 4/5 studies that administered a 50 units/kg dose. The mortality rates were < 20% in 7/9 studies with hemostatic effectiveness rates ≥ 79%. Mortality rates were lower in the studies demonstrating higher hemostatic effectiveness rates and including patients with higher Glasgow coma scale scores and lower intracerebral hemorrhage volumes. Overall, the thromboembolic event rates were 0-18%, with 16/18 studies demonstrating rates ≤ 10%. The thromboembolic event rates were not dose or agent dependent.

CONCLUSION

Rates of hemostatic effectiveness were influenced by the definition of hemostatic effectiveness, dose administered, and patient severity. Studies suggest that higher doses may result in higher hemostatic effectiveness rates without increasing the risk of experiencing a thromboembolic event. This review may be used by providers to modify or validate their reversal strategy approach until well designed studies are available.