Andexanet alfa and four-factor prothrombin complex concentrate for reversal of apixaban and rivaroxaban in patients diagnosed with intracranial hemorrhage

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.

Advances in the medical treatment and diagnosis of intracranial hemorrhage associated with oral anticoagulation

INTRODUCTION

With the increasing prevalence of atrial fibrillation (AF), it entails expanding oral anticoagulants (OACs) use, carrying a higher risk of associated hemorrhagic events, including intracranial hemorrhage (ICH). Despite advances in OACs development with a better safety profile and reversal agent for these anticoagulants, there is still no consensus on the optimal management of patients with OACs-associated ICH.

AREAS COVERED

In this review, the authors have carried out an exhaustive search on the advances in recent years. The authors provide an update on the management of ICH in anticoagulated patients, as well as an update on the latest evidence on anticoagulation resumption, recent therapeutic strategies, and investigational drugs that could play a role in the future.

EXPERT OPINION

Following an ICH event in an anticoagulated patient, a comprehensive clinical evaluation is imperative. Anticoagulation should be promptly withdrawn and reversed. Once the patient is stabilized, a reintroduction of anticoagulation should be considered, typically within a timeframe of 4-8 weeks, if feasible. If re-anticoagulation is not possible, alternative options such as Left Atrial Appendage Occlusion are available.

Improving Patient Safety Through Proper Ordering and Administration of Andexanet Alfa

Objective

To evaluate prescribing practices for the anti-Xa reversal agent, andexanet alfa, to identify challenges in ordering and administering this medication, and to offer recommendations to improve patient safety.

Patients and Methods

This retrospective study reviewed all adult patients treated with andexanet alfa (AA) at a single institution between January 1, 2018, and March 31, 2020. We identified ordering and administration benchmarks based on recommendations from previous clinical trials on AA. We then reviewed these medical records to determine compliance with these benchmarks. We also collected data related to thrombotic complications and mortality.

Results

Twenty-two AA dosing sets (loading and infusion dose) were given to 20 patients. Eight (36%) dosing sets met our ordering benchmarks regarding appropriate dose, time since last direct oral anticoagulants, urgency of administration, and documentation. Three (14%) dosing sets met the administrative benchmarks of being started within 30 minutes of the initial order, and 13 (59%) dosing sets had timely infusion of the infusion dose after the loading dose. No dosing set met all our administration benchmarks. There was 1 thrombotic event within 24 hours of the correct AA dose and 1 potential death related to AA.

Conclusion

This study highlights challenges in ordering and administering AA at our institution and brings awareness to potential similar concerns at other institutions. These challenges also identified the need for optimized order sets, a streamlined administration process, and frequent provider education to improve patient safety.

Andexanet alpha versus four-factor prothrombin complex concentrate in DOACs anticoagulation reversal: an updated systematic review and meta-analysis

BACKGROUND

There is currently a lack of evidence for the comparative effectiveness of Andexanet alpha and four-factor prothrombin complex concentrate (4F-PCC) in anticoagulation reversal of direct oral anticoagulants (DOACs). The primary aim of our systematic review was to verify which drug is more effective in reducing short-term all-cause mortality. The secondary aim was to determine which of the two reverting strategies is less affected by thromboembolic events.

METHODS

A systematic review and meta-analysis was performed.

RESULTS

Twenty-two studies were analysed in the systematic review and quantitative synthesis. In all-cause short-term mortality, Andexanet alpha showed a risk ratio (RR) of 0.71(95% CI 0.37-1.34) in RCTs and PSMs, compared to 4F-PCC (I2 = 81%). Considering the retrospective studies, the pooled RR resulted in 0.84 (95% CI 0.69-1.01) for the common effects model and 0.82 (95% CI 0.63-1.07) for the random effects model (I2 = 34.2%). Regarding the incidence of thromboembolic events, for RCTs and PSMs, the common and the random effects model exhibited a RR of 1.74 (95% CI 1.09-2.77), and 1.71 (95% CI 1.01-2.89), respectively, for Andexanet alpha compared to 4F-PCC (I2 = 0%). Considering the retrospective studies, the pooled RR resulted in 1.21 (95% CI 0.87-1.69) for the common effects model and 1.18 (95% CI 0.86-1.62) for the random effects model (I2 = 0%).

CONCLUSION

Considering a large group of both retrospective and controlled studies, Andexanet alpha did not show a statistically significant advantage over 4F-PCC in terms of mortality. In the analysis of the controlled studies alone, Andexanet alpha is associated with an increased risk of thromboembolic events.

CLINICAL TRIAL REGISTRATION

PROSPERO: International prospective register of systematic reviews, 2024, CRD42024548768.

Reprint of: Four-factor prothrombin complex concentrate versus andexanet alfa for direct oral anticoagulant reversal

BACKGROUND

Optimal reversal agent for direct oral anticoagulant (DOAC)-associated major bleeding has not been described. Before the approval of andexanet alfa (AA) in 2018, 4-factor prothrombin complex concentrate (4F-PCC) was recommended by major guidelines. Currently, AA is recommended as the first-line agent by most guidelines. With a paucity of literature comparing the 2 agents, there is clinical value in assessing hemostatic efficacy and safety of the 2 agents.

OBJECTIVE

This study aimed to evaluate hemostatic efficacy and safety of AA and 4F-PCC in all DOAC-associated major bleedings.

METHODS

A multicenter, retrospective chart review was performed of adult subjects who were admitted for a DOAC-associated major bleeding and received 4F-PCC from February 2018 to May 2019 or AA from May 2019 to September 2021. Some of the exclusion criteria included not receiving a DOAC, receiving multiple reversal agents during the same hospitalization, receiving reversal for any nonmajor bleeding indication, and not receiving the full dose of a reversal agent. The primary outcome was hemostatic efficacy 24 hours after the end of the reversal agent administration. Secondary outcomes included time to administration, hospital mortality, length of stay, need for surgery, and need for additional blood product. Safety outcome was incidence of thrombotic events.

RESULTS

There were 99 subjects included in the 4F-PCC group and 84 subjects in the AA group. Hemostatic efficacy was achieved in 69 subjects (69.7%) in the 4F-PCC group and 63 subjects (75%) in the AA group (P = 0.927). In-hospital mortality was seen in 20 subjects (20.2%) in the 4F-PCC group and 10 subjects (11.9%) in the AA group. Thrombotic events were seen in 7 subjects (7.1%) in the 4F-PCC group and 6 subjects (7.1%) in the AA group.

CONCLUSIONS

There were no significant differences in hemostatic efficacy, in-hospital mortality, and number of thrombotic events between 4F-PCC and AA.

[Current Aspects of Intensive Medical Care for Traumatic Brain Injury - Part 2 - Secondary Treatment Strategies, Long-term Outcome, Neuroprognostics and Chronification]

This two-part article deals with the intensive medical care of traumatic brain injury. Part 1 addresses the primary treatment strategy, haemodynamic management and multimodal monitoring, Part 2 secondary treatment strategies, long-term outcome, neuroprognostics and chronification. Traumatic brain injury is a complex clinical entity with a high mortality rate. The primary aim is to maintain homeostasis based on physiological targeted values. In addition, further therapy must be geared towards intracranial pressure. In addition to this, there are other monitoring options that appear sensible from a pathophysiological point of view with appropriate therapy adjustment. However, there is still a lack of data on their effectiveness. A further aspect is the inflammation of the cerebrum with the "cross-talk" of the organs, which has a significant influence on further intensive medical care.

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.

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

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

Andexanet alfa versus PCC products for factor Xa inhibitor bleeding: A systematic review with meta-analysis

Previous meta-analyses assessed andexanet alfa (AA) or prothrombin complex concentrate (PCC) products for the treatment of Factor Xa inhibitor (FXaI)-associated major bleeding. However, they did not include recent studies or assess the impact of the risk of bias. We conducted a systematic review with meta-analysis on the effectiveness of AA versus PCC products for FXaI-associated major bleeding, inclusive of the studies' risk of bias. PubMed and Embase were searched for comparative studies assessing major bleeding in patients using FXaI who received AA or PCC. We used the Methodological Index for NOn-Randomized Studies (MINORS) checklist and one question from the Joanna Briggs Institute (JBI) Critical Appraisal of Case Series tool to assess the risk of bias. Random-effects meta-analyses were performed to provide a pooled estimate for the effect of AA versus PCC products on hemostatic efficacy, in-hospital mortality, 30-day mortality, and thrombotic events. Low-moderate risk of bias studies were meta-analyzed separately, as well as combined with high risk of bias studies. Eighteen comparative evaluations of AA versus PCC were identified. Twenty-eight percent of the studies (n = 5) had low-moderate risk and 72% (n = 13) had a high risk of bias. Studies with low-moderate risk of bias suggested improvements in hemostatic efficacy [Odds Ratio (OR) 2.72 (95% Confidence Interval (CI): 1.15-6.44); one study], lower in-hospital mortality [OR 0.48 (95% CI: 0.38-0.61); three studies], and reduced 30-day mortality [OR 0.49 (95% CI: 0.30-0.80); two studies] when AA was used versus PCC products. When studies were included regardless of the risk of bias, pooled effects showed improvements in hemostatic efficacy [OR 1.36 (95% CI: 1.01-1.84); 12 studies] and reductions in 30-day mortality [OR 0.53 (95% CI: 0.37-0.76); six studies] for AA versus PCC. The difference in thrombotic events with AA versus PCC was not statistically significant in the low-moderate, high, or combined risk of bias groups. The evidence from low-moderate quality real-world studies suggests that AA is superior to PCC in enhancing hemostatic efficacy and reducing in-hospital and 30-day mortality. When studies are assessed regardless of the risk of bias, the pooled hemostatic efficacy and 30-day mortality risk remain significantly better with AA versus PCC.

Ultra-Early Hemostatic Therapy for Acute Intracerebral Hemorrhage: An Updated Review

Intracerebral hemorrhage (ICH) is the second most common type of stroke, accounting for approximately 10-20% of all strokes, and is linked to severe neurological disability and death. Since the most accurate predictor of outcome in patients with ICH is hematoma volume, there is a great need for pharmacologic therapy that can reduce hematoma expansion and resultant mass effect and edema. This is especially critical within the ultra-early window of 3-4 hours after the presentation. Hemostatic therapies are exceptionally important for those patients taking antiplatelet or anticoagulant medications to reverse the effects of these medications and therefore prevent hematoma expansion. Furthermore, the recent publication of the 2023 Guideline for the Management of Patients with Aneurysmal Subarachnoid Hemorrhage by the American Heart Association/American Stroke Association, the first update to the guidelines since 2012, underscores the importance of optimizing anticoagulation reversal for this population. The purpose of this selective, nonsystematic review is to examine current literature regarding the use of hemostatic therapies in ICH, with particular attention paid to antiplatelet, anticoagulation, and antifibrinolytic therapies.

Four-factor prothrombin complex concentrate versus andexanet alfa for direct oral anticoagulant reversal

BACKGROUND

Optimal reversal agent for direct oral anticoagulant (DOAC)-associated major bleeding has not been described. Before the approval of andexanet alfa (AA) in 2018, 4-factor prothrombin complex concentrate (4F-PCC) was recommended by major guidelines. Currently, AA is recommended as the first-line agent by most guidelines. With a paucity of literature comparing the 2 agents, there is clinical value in assessing hemostatic efficacy and safety of the 2 agents.

OBJECTIVE

This study aimed to evaluate hemostatic efficacy and safety of AA and 4F-PCC in all DOAC-associated major bleedings.

METHODS

A multicenter, retrospective chart review was performed of adult subjects who were admitted for a DOAC-associated major bleeding and received 4F-PCC from February 2018 to May 2019 or AA from May 2019 to September 2021. Some of the exclusion criteria included not receiving a DOAC, receiving multiple reversal agents during the same hospitalization, receiving reversal for any nonmajor bleeding indication, and not receiving the full dose of a reversal agent. The primary outcome was hemostatic efficacy 24 hours after the end of the reversal agent administration. Secondary outcomes included time to administration, hospital mortality, length of stay, need for surgery, and need for additional blood product. Safety outcome was incidence of thrombotic events.

RESULTS

There were 99 subjects included in the 4F-PCC group and 84 subjects in the AA group. Hemostatic efficacy was achieved in 69 subjects (69.7%) in the 4F-PCC group and 63 subjects (75%) in the AA group (P = 0.927). In-hospital mortality was seen in 20 subjects (20.2%) in the 4F-PCC group and 10 subjects (11.9%) in the AA group. Thrombotic events were seen in 7 subjects (7.1%) in the 4F-PCC group and 6 subjects (7.1%) in the AA group.

CONCLUSIONS

There were no significant differences in hemostatic efficacy, in-hospital mortality, and number of thrombotic events between 4F-PCC and AA.

Characterization of an andexanet alfa administration protocol guided by drug-specific quantitative anti-Xa assays

Following FDA approval in 2018, consensus guidelines recommend andexanet alfa as first-line therapy for the management of life-threatening or uncontrollable bleeding in patients taking oral factor Xa (FXa) inhibitors. Dosing is based on the specific FXa inhibitor and dose, and the time elapsed since the patient's last administration of the medication. Additionally, at our institution, anti-FXa screens and drug-specific assays are obtained to guide subsequent dosing based on institution protocol. The objective of this study was to evaluate andexanet alfa utilization based on anti-Xa and FXa-inhibitor-specific assays and assess associated outcomes. This was a retrospective, single-center study aimed to describe the use of anti-FXa and specific direct oral anticoagulant assays to guide the utilization and administration of andexanet alfa. Secondary endpoints evaluated included thrombotic events during index hospitalization, hospital length of stay, hospital mortality, and discharge disposition. Overall, most patients were prescribed apixaban for atrial fibrillation and received andexanet alfa for reversal of intracranial hemorrhage in the emergency department. In general, DOAC-specific assays were concordant with last known times; however, there appears to be minimal correlation with DOAC-specific assay levels and survival. There were 9 thrombotic events (8.7%) in 8 patients. In this cohort, collection of an anti-FXa assay screen was a practical strategy to guide reversal with andexanet alfa; however, the addition of DOAC-specific assay levels may not enhance clinical utility.

Real-World Reversal of Factor Xa Inhibition in the Setting of Major Life-Threatening Bleeding or Urgent Surgery

Background: Management of major life-threatening bleeding with factor Xa (FXa) inhibition poses complex challenges involving novel direct reversal agents competing with non-specific preexisting strategies. The recent availability of andexanet alfa (AA) led to a health-system guideline incorporating its use alongside the most commonly used historic agent, four-factor prothrombin complex concentrate (4F-PCC). Objectives: The objective was to characterize the use and efficacy of AA and 4F-PCC for reversal of FXa inhibition after implementation of the health-system guideline. Methods: This multi-hospital, retrospective cohort study included patients aged >18 years administered either AA or 4F-PCC between October 2018 to June 2020 with the indication for urgent reversal of FXa inhibitor-induced coagulopathy. The primary outcome assessed hemostatic efficacy between treatment groups. Secondary outcomes evaluated adjunct blood product administration, incidence of repeat pharmacologic reversal, incidence of thromboembolism, intensive care unit and hospital length of stays, and in-hospital mortality. Results: Eighty-five patients were included; 33 patients received AA and 52 patients received 4F-PCC. Effective hemostasis was achieved at similar rates in both treatment groups (84.8% vs 76.9%; P = .373). Thrombotic events occurring during the observed hospitalization were more frequent among the AA treated group (18% vs 3.8%, P = .027). No differences were observed for other secondary outcomes. Conclusion: Guideline use resulted in similar rates of effective hemostasis with a higher incidence of VTE in patients receiving AA. Further exploration with a larger, prospective study to evaluate these findings is warranted.

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.

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.

Deterioration free discharge comparison of andexanet-alfa and prothrombin complex concentrates (PCC) for reversal of factor Xa inhibitor associated bleeds

Given the paucity of comparative efficacy data and the difference in cost between andexanet-alfa and prothrombin complex concentrates (PCC), debates continue regarding optimal cost-effective therapy for patients who present with major bleeding associated with oral factor Xa inhibitors. Available literature comparing the cost-effectiveness of the reversal agents is limited, and the large difference in price between therapy options has led many health systems to exclude andexanet-alfa from their formularies. To evaluate the clinical outcomes and cost of PCC compared to andexanet-alfa for patients with factor Xa inhibitor associated bleeds. We performed a quasi-experimental, single health system study of patients treated with PCC or andexanet-alfa from March 2014 to April 2021. Deterioration-free discharge, thrombotic events, length of stay, discharge disposition, and cost were reported. 170 patients were included in the PCC group and 170 patients were included in the andexanet-alfa group. Deterioration-free discharge was achieved in 66.5% of PCC-treated patients compared to 69.4% in the andexanet alfa-treated patients. 31.8% of PCC-treated patients were discharged home compared to 30.6% in the andexanet alfa-treated patients. The cost per deterioration-free discharge was $20,773.62 versus $5230.32 in the andexanet alfa and 4 F-PCC group, respectively. Among patients that experienced a bleed while taking a factor Xa inhibitor, there was no difference in clinical outcomes for patients treated with andexanet-alfa compared to PCC. Although there was no difference in the clinical outcomes, there was a significant difference in cost with andexanet-alfa costing approximately four times as much as PCC per deterioration-free discharge.

Andexanet Alfa to Reverse the Effect of Factor Xa Inhibitors in Intracranial Hemorrhage

Andexanet alfa (AA) is a recombinant factor Xa competing for binding with factor Xa inhibitors, thereby reversing their anticoagulation effects. Since 2019, it has been approved for individuals under apixaban or rivaroxaban therapy suffering from life-threatening or uncontrolled bleeding. Apart from the pivotal trial, real-world data on the use of AA in daily clinics are scarce. We reviewed the current literature on patients with intracranial hemorrhage (ICH) and summarized the available evidence regarding several outcome parameters. On the basis of this evidence, we provide a standard operating procedure (SOP) for routine AA application. We searched PubMed and additional databases through 18 January 2023 for case reports, case series, studies, reviews, and guidelines. Data on hemostatic efficacy, in-hospital mortality, and thrombotic events were pooled and compared with the pivotal trial data. While hemostatic efficacy in world-wide clinical routine seems to be comparable to the pivotal trial, thrombotic events and in-hospital mortality appear to be substantially higher. Various confounding factors responsible for this finding such as exclusion and inclusion criteria resulting in a highly selected patient cohort within the controlled clinical trial have to be considered. The SOP provided should support physicians in patient selection for AA treatment as well as facilitate routine use and dosing. This review underlines the urgent need for more data from randomized trials to appreciate the benefit and safety profile of AA. Meanwhile, this SOP should help to improve frequency and quality of AA use in patients suffering from ICH while on apixaban or rivaroxaban treatment.

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.

Emergent external ventricular drain placement in patients with factor Xa inhibitor-associated intracerebral hemorrhage after reversal with andexanet alfa

BACKGROUND

Andexanet alfa (AA), a factor Xa-inhibitor (FXi) reversal agent, is given as a bolus followed by a 2-hour infusion. This long administration time can delay EVD placement in intracerebral hemorrhage (ICH) patients. We sought to evaluate the safety of EVD placement immediately post-AA bolus compared to post-AA infusion.

METHODS

We conducted a retrospective study that included adult patients admitted with FXi-associated ICH who received AA and underwent EVD placement The primary outcome was the occurrence of a new hemorrhage (tract, extra-axial, or intraventricular hemorrhage). Secondary outcomes included mortality, intensive care unit and hospital length of stay, and discharge modified Rankin Score. The primary safety outcome was documented thrombotic events.

RESULTS

Twelve patients with FXi related ICH were included (EVD placement post-AA bolus, N = 8; EVD placement post-AA infusion, N = 4). Each arm included one patient with bilateral EVD placed. There was no difference in the incidence of new hemorrhages, with one post-AA bolus patient had small, focal, nonoperative extra-axial hemorrhage. Morbidity and mortality were higher in post-AA infusion patients (mRS, post-AA bolus, 4 [4-6] vs. post-AA infusion 6 [5,6], p = 0.24 and post-AA bolus, 3 (37.5 %) vs. post-AA infusion, 3 (75 %), p = 0.54, respectively). One patient in the post-AA bolus group had thrombotic event. There was no difference in hospital LOS (post-AA bolus, 19 days [12-26] vs. post-AA infusion, 14 days [9-22], p = 0.55) and ICU LOS (post-AA bolus, 10 days [6-13] vs. post-AA infusion, 11 days [5-21], p = 0.86).

CONCLUSION

We report no differences in the incidence of tract hemorrhage, extra-axial hemorrhage, or intraventricular hemorrhage post-AA bolus versus post-AA infusion. Larger prospective studies to validate these results are warranted.

The use of andexanet alfa and 4-factor prothrombin complex concentrate in intracranial hemorrhage

OBJECTIVE

to describe the clinical and safety outcomes between andexanet alfa (AA) and 4-factor prothrombin complex concentrate (4F-PCC) for the reversal of apixaban or rivaroxaban in the setting of an intracranial hemorrhage (ICH).

METHODS

A retrospective, multicentered descriptive study was conducted in hospitalized patients 18 years of age or older from June 2018 to October 2019 who received AA or 4F-PCC for the reversal of apixaban or rivaroxaban in the setting of ICH. Patients were excluded if they had received 4F-PCC prior to AA after its addition to the institution wide formulary. Other exclusion criteria were history or presence of heparin-induced thrombocytopenia or disseminated intravascular coagulation, estimated hematoma volume of >60 mL, Glasgow Coma Scores <7, or no repeat CT head scan. Information was collected from the electronic medical records. The primary outcome was the achievement of excellent or good hemostatic efficacy upon the repeat computer tomography (CT) scan performed after the infusion of study drugs. Secondary outcomes included disposition, survival to hospital discharge, 30-day readmission, length of hospital stay, length of ICU stay, incidence of thromboembolic events.

RESULTS

A total of 24 patients were included in the study, of which 9 received AA and 15 received 4F-PCC. The achievement of excellent or good hemostatic efficacy upon repeat CT scan occurred in 7 (77.8%) patients in the AA group and in 14 (93.3%) patients in the 4-F PCC group. All patients in the AA group survived to hospital discharge with no 30-day morality and 86.7% patients in the 4F-PCC group.

CONCLUSION

This study suggests that real-world clinical and safety outcomes between andexanet alfa and 4F-PCC for the reversal of factor Xa inhibitors in the setting of ICH are similar to ones reported in clinical trials.

Retrospective review of Andexanet Alfa versus 4-Factor Prothrombin Complex Concentrate for reversal of DOAC-Associated Intracranial Hemorrhage

 Background: Mortality of oral anticoagulation-associated ICH is around 60%, with oral anticoagulation increasing the risk of ICH seven to ten-fold compared to no anticoagulation. Current guidelines recommend DOACs (direct oral anticoagulants) as first-line therapy in the treatment of VTE (Venous Thromboembolism) due to their more favorable safety profile. There are two agents available for DOAC reversal, Coagulation Factor Xa (recombinant), inactivated-zhzo (andexanet alfa, Andexxa®) and 4-factor prothrombin complex concentrate (4FPCC). There is little data comparing the two agents in real-life clinical settings.

OBJECTIVE

The primary objective of this study was to determine if there was a difference in hemostatic efficacy of andexanet alfa and 4FPCC in patients with a factor Xa inhibitor-related intracranial hemorrhage.

METHODS

This was a retrospective, single-center study conducted in adult patients admitted at a quaternary academic medical center from September 2017 to March 2021. Adults with a diagnosis of intracranial hemorrhage (ICH) were included if they received either 4FPCC or andexanet alfa for reversal of apixaban or rivaroxaban. In addition to hemostatic efficacy per imaging, we assessed disposition location, cerebral performance score, blood product consumption, and the development of a new thrombus.

RESULTS

A total of 46 patients were included in this study, 15 received 4FPCC (32%) and 31 received andexanet alfa (68%). There was no difference in the proportion of patients with excellent (4FPCC 9 [60%] vs. andexanet alfa 16 [51.6%], p = 0.61), good (4FPCC 2 [13.3%] vs. andexanet alfa 7 [22.6%]), or poor (4FPCC 1 [6.7%] vs. andexanet alfa 5 [16.1%]) hemostasis after administration of each agent. There were no significant differences in any secondary outcomes.

CONCLUSION AND RELEVANCE

Our study found no difference in hemostatic efficacy between andexanet alfa and 4FPCC. At this time, clinicians should choose an agent based on individual patient presentation and resource availability. Further research will help clarify the role of each agent in the management of DOAC-related intracranial hemorrhage.

Differential Neutralization of Apixaban, Betrixaban, Edoxaban, and Rivaroxaban by Andexanet Alfa as Measured by Whole Blood Thromboelastographic Analysis

INTRODUCTION

The available oral anti-Xa agents are routinely used for the management of thrombotic disorders. A molecularly modified recombinant coagulation FXa, also known as Andexanet Alfa (AA), that has been developed as an antidote to neutralize the bleeding effects of oral FXa inhibitors, such as Apixaban and Rivaroxaban.

MATERIALS AND METHODS

This study utilized thromboelastography (TEG 5000 Hemostasis System), to investigate the neutralizing effects of AA at different concentrations of oral FXa inhibitors measuring such parameters as R-Time, K-Time, Angle, and Max Amplitude (MA). Apixaban, Betrixaban, Edoxaban, and Rivaroxaban were obtained commercially in powdered form. Each of these drugs was supplemented with freshly drawn whole citrated blood at a concentration of 1 μg/mL. And subsequently mixed with AA at 50 or 100 μg/mL.

RESULTS

At a concentration of 1 μg/mL, all FXa inhibitors produced variable anticoagulant effects in the order of Edoxaban > Betrixaban > Rivaroxaban > Apixaban. AA at 100 μg/mL produced a complete neutralization of these inhibitors whereas at 50 μg/mL relatively weaker neutralization as measured by various parameters.

CONCLUSION

These results suggest that regardless of the variable anticoagulant effects exhibited by the FXa Inhibitors, AA at FC = 100 μg/mL fully neutralized these agents as measured by the TEG parameters. AA was shown to be more effective in neutralizing Betrixaban and least effective in Apixaban. The neutralization of various FXa inhibitors was dose and donor-dependent warranting dosage adjustment for optimal outcomes.

Evaluation of Direct Oral Anticoagulant Reversal Agents in Intracranial Hemorrhage: A Systematic Review and Meta-analysis

IMPORTANCE

Direct oral anticoagulant (DOAC)-associated intracranial hemorrhage (ICH) has high morbidity and mortality. The safety and outcome data of DOAC reversal agents in ICH are limited.

OBJECTIVE

To evaluate the safety and outcomes of DOAC reversal agents among patients with ICH.

DATA SOURCES

PubMed, MEDLINE, The Cochrane Library, Embase, EBSCO, Web of Science, and CINAHL databases were searched from inception through April 29, 2022.

STUDY SELECTION

The eligibility criteria were (1) adult patients (age ≥18 years) with ICH receiving treatment with a DOAC, (2) reversal of DOAC, and (3) reported safety and anticoagulation reversal outcomes. All nonhuman studies and case reports, studies evaluating patients with ischemic stroke requiring anticoagulation reversal or different dosing regimens of DOAC reversal agents, and mixed study groups with DOAC and warfarin were excluded.

DATA EXTRACTION AND SYNTHESIS

Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were used for abstracting data and assessing data quality and validity. Two reviewers independently selected the studies and abstracted data. Data were pooled using the random-effects model.

MAIN OUTCOMES AND MEASURES

The primary outcome was proportion with anticoagulation reversed. The primary safety end points were all-cause mortality and thromboembolic events after the reversal agent.

RESULTS

A total of 36 studies met criteria for inclusion, with a total of 1832 patients (967 receiving 4-factor prothrombin complex concentrate [4F-PCC]; 525, andexanet alfa [AA]; 340, idarucizumab). The mean age was 76 (range, 68-83) years, and 57% were men. For 4F-PCC, anticoagulation reversal was 77% (95% CI, 72%-82%; I2 = 55%); all-cause mortality, 26% (95% CI, 20%-32%; I2 = 68%), and thromboembolic events, 8% (95% CI, 5%-12%; I2 = 41%). For AA, anticoagulation reversal was 75% (95% CI, 67%-81%; I2 = 48%); all-cause mortality, 24% (95% CI, 16%-34%; I2 = 73%), and thromboembolic events, 14% (95% CI, 10%-19%; I2 = 16%). Idarucizumab for reversal of dabigatran had an anticoagulation reversal rate of 82% (95% CI, 55%-95%; I2 = 41%), all-cause mortality, 11% (95% CI, 8%-15%, I2 = 0%), and thromboembolic events, 5% (95% CI, 3%-8%; I2 = 0%). A direct retrospective comparison of 4F-PCC and AA showed no differences in anticoagulation reversal, proportional mortality, or thromboembolic events.

CONCLUSIONS AND RELEVANCE

In the absence of randomized clinical comparison trials, the overall anticoagulation reversal, mortality, and thromboembolic event rates in this systematic review and meta-analysis appeared similar among available DOAC reversal agents for managing ICH. Cost, institutional formulary status, and availability may restrict reversal agent choice, particularly in small community hospitals.

Andexanet-Alfa-Associated Heparin Resistance in the Context of Hemorrhagic Stroke

Background

With a growing number of patients on new oral anticoagulants, interest in reversal agents is rising. Andexanet alfa is used for reversal of factor Xa inhibitors in intracranial hemorrhage.

Methods

We provide a brief review on andexanet-alfa-associated heparin resistance and discuss potentially critical situations from different clinical perspectives.

Results

Case reports point out that andexanet alfa can cause unresponsiveness to heparin, leading to catastrophic events. As a result, regulatory bodies have issued warning notices to avoid heparinization parallel to the use of andexanet alfa.

Conclusions

Although well known to hematologists, the phenomenon is underrecognized among stroke clinicians. However, patients with intracranial hemorrhage frequently undergo endovascular or surgical interventions that require periprocedural administration of heparin.

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.

Cerebral Hemorrhage: Pathophysiology, Treatment, and Future Directions

Intracerebral hemorrhage (ICH) is a devastating form of stroke with high morbidity and mortality. This review article focuses on the epidemiology, cause, mechanisms of injury, current treatment strategies, and future research directions of ICH. Incidence of hemorrhagic stroke has increased worldwide over the past 40 years, with shifts in the cause over time as hypertension management has improved and anticoagulant use has increased. Preclinical and clinical trials have elucidated the underlying ICH cause and mechanisms of injury from ICH including the complex interaction between edema, inflammation, iron-induced injury, and oxidative stress. Several trials have investigated optimal medical and surgical management of ICH without clear improvement in survival and functional outcomes. Ongoing research into novel approaches for ICH management provide hope for reducing the devastating effect of this disease in the future. Areas of promise in ICH therapy include prognostic biomarkers and primary prevention based on disease pathobiology, ultra-early hemostatic therapy, minimally invasive surgery, and perihematomal protection against inflammatory brain injury.