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

Improve time to anti-coagulation reversal for hemorrhagic strokes

BACKGROUND

Oral anticoagulation (OAC) is a risk factor for intracerebral hemorrhage (ICH) which is an important source of disability and mortality. OAC-associated ICH (OAC-ICH) patients have worse outcomes as compared to ICH patients not on OAC, likely because of the associated larger stroke volumes, higher propensity to intraventricular hemorrhage, and a higher risk of rebleeding. Although current guidelines recommend that OAC should be reversed quickly, many health care systems have not developed a process for optimizing that aspect of care.

METHODS

Through the IMPROVE Stroke Care Consortium, a group of nine Hub hospitals and their 57 regional community hospitals, a systems of care improvement project was implemented. Performance reviews identified best practices which were disseminated throughout all centers. We compared the median door-to-reversal (DTR) time before and after an institutional campaign to speed the process with a target time of 60 min.

RESULTS

Over two years of the study, there were 6,699 ischemic strokes, 152 subarachnoid hemorrhages, and 889 intracerebral hemorrhages. During that time, 73 ICH patients received reversal agents emergently. The overall baseline median DTR time was 123 min (IQR 99, 361 minutes). By the end of the program, the median DTR time had trended down to 84 min (IQR 58.5, 151 min) which is a 31.7 % reduction of DTR from baseline, though times remained somewhat variable (p=0.08).

CONCLUSIONS

An integrated stroke systems of care approach was associated with a reduction in DTR times for patients presenting with acute ICH and concurrent use of anticoagulants despite lack of definitive guidelines around targets for OAC reversal times or operational guidance on protocols and agents.

Effect of Mild Therapeutic Hypothermia Combined with Stereotactic Aspiration on Patients with Severe Cerebral Hemorrhage

This study aimed to investigate the effects of mild therapeutic hypothermia combined with stereotactic aspiration of spontaneous intracerebral hematoma on neurological function, inflammatory markers, cerebral hematoma, and cerebral edema in patients with severe cerebral hemorrhage. The clinical data of 86 patients with severe cerebral hemorrhage treated at our hospital between March 2020 and January 2022 were retrospectively analyzed. The patients were grouped according to their treatment plans: the control group consisted of 40 patients who underwent stereotactic aspiration of the spontaneous intracerebral hematoma, whereas the study group consisted of 46 patients who received adjuvant mild therapeutic hypothermia in addition to the aforementioned treatment. Clinical efficacy, neurological function (NIHSS score), daily living ability (BI score), cerebral hematoma, cerebral edema, cerebral hemodynamics (PI, RI, Vm, Vd), inflammatory markers (IL-6, IL-8, TNF-α, hs-CRP), oxidative stress indicators (SOD, MDA, 8-iso-PGF2α), serum-related factors (MMP-9, ICAM-1, ET-1, NO), and prognosis were compared between the groups. The total efficacy rate in the study group (95.65%) was significantly higher than that in the control group (77.50%) (P < 0.05). Post-treatment NIHSS scores, intracranial hematoma volume, perihematoma edema volume, cerebral edema volume, RI, serum IL-6, IL-8, TNF-α, hs-CRP, MDA, and 8-iso-PGF2α levels were significantly lower in both groups, with the study group showing even greater reductions. The BI score and PI, Vm, Vd, SOD, and NO levels were significantly higher in the study group (P < 0.05). At the 6-month follow-up, the prognosis of patients in the intervention group was significantly better than that of patients in the control group (P < 0.05). The combination of mild therapeutic hypothermia with stereotactic aspiration of a spontaneous intracerebral hematoma has demonstrated efficacy in the treatment of severe cerebral hemorrhage. This approach effectively reduces cerebral hematoma and edema, improves daily living ability, alleviates neurological deficits, regulates cerebral hemodynamics, suppresses inflammatory responses and oxidative stress, modulates serum-related factor levels, and enhances patient prognosis.

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.

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.

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.

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

BACKGROUND

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

DESIGN

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

RESULTS

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

DISCUSSION

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

CONCLUSION

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

Reversal and resumption of anticoagulants in patients with anticoagulant-associated intracerebral hemorrhage

The use of anticoagulants has become more frequent due to the progressive aging population and increased thromboembolic events. Consequently, the proportion of anticoagulant-associated intracerebral hemorrhage (AAICH) in stroke patients is gradually increasing. Compared with intracerebral hemorrhage (ICH) patients without coagulopathy, patients with AAICH may have larger hematomas, worse prognoses, and higher mortality. Given the need for anticoagulant reversal and resumption, the management of AAICH differs from that of conventional medical or surgical treatments for ICH, and it is more specific. Understanding the pharmacology of anticoagulants and identifying agents that can reverse their effects in the early stages are crucial for treating life-threatening AAICH. When patients transition beyond the acute phase and their vital signs stabilize, it is important to consider resuming anticoagulants at the right time to prevent the occurrence of further thromboembolism. However, the timing and strategy for reversing and resuming anticoagulants are still in a dilemma. Herein, we summarize the important clinical studies, reviews, and related guidelines published in the past few years that focus on the reversal and resumption of anticoagulants in AAICH patients to help implement decisive diagnosis and treatment strategies in the clinical setting.

ANMCO/SIMEU consensus document on the use of reversal agents for antithrombotic therapies in patients with ongoing bleeding or at high risk of haemorrhagic events

In recent decades, an incredible evolution in antithrombotic therapies used for treating patients with atherosclerosis, atrial fibrillation, and venous thromboembolism has been observed, leading to the availability of increasingly safe drugs. Nonetheless, bleeding complications remain a significant concern, with considerable health, social, and economic implications. To improve the acute management of patients experiencing or at risk for major bleeding events, specific reversal agents for antithrombotic drugs have been recently developed. While these agents demonstrate effectiveness in small-scale pharmacodynamic studies and clinical trials, it is imperative to balance the benefits of reversing antiplatelet or anticoagulant therapy against the risk of prothrombotic effects. These risks include the potential loss of antithrombotic protection and the prothrombotic tendencies associated with bleeding, major surgery, or trauma. This joint document of the Italian Association of Hospital Cardiologists (Associazione Nazionale Medici Cardiologi Ospedalieri) and the Italian Society of Emergency Medicine (Società Italiana di Medicina d'Emergenza-Urgenza) delineates the key features and efficacy of available reversal agents. It also provides practical flowcharts to guide their use in patients with active bleeding or those at elevated risk of major bleeding events.

The current status of reversal therapy in Japan for elderly patients with head injury treated with antithrombotic agents: A prospective multicenter observational study

Background

Acute exacerbation of head injury in elderly patients due to use of antithrombotic agents has become a concern in countries with aging populations. Reversal agents are recommended for treatment, but its usage is unclear. Therefore, we conducted a prospective observational study in this patient population to monitor usage of reversal therapy.

Methods

The subjects were 721 elderly patients aged ≥65 years old who were hospitalized in 15 centers from December 2019 to May 2021. Patients were divided into groups who did not receive antithrombotic agents (Group A), who received antithrombotic agents, but did not receive reversal therapy (Group B), and were treated with antithrombotic agents and reversal therapy (Group C). Age, gender, mechanism of injury, neurologic and imaging findings on admission, clinical course after admission and surgery, outcomes and complications were compared among these groups. Time from injury to reversal therapy was examined based on outcomes to investigate trends in the timing of administration of the reversal agent.

Results

Acute exacerbation during the clinical course occurred in 9.8 %, 15.8 % and 31.0 % of cases in Groups A, B and C, respectively, and differed significantly among the groups. On head CT, the incidences of hematoma were 35.7 %, 36.5 % and 60.4 %, respectively, with this incidence being significantly higher in Group C; and the respective rates of craniotomy were 18.8 %, 14.0 % and 50.9 %, again with this rate being significantly higher in Group C. The good outcome and mortality rates were 57.1 %, 52.5 % and 35.8 %, and 14.5 %, 18.0 % and 24.5 %, respectively, and both were poorest in Group C. Times from injury to treatment with a reversal agent were significantly shorter in patients without compared to those with acute exacerbation (405.9 vs. 880.8 min) and in patients with favorable outcomes compared to those with unfavorable outcomes (261.9 vs. 543.4 min).

Conclusion

Similarly to previous studies, the incidence of acute exacerbation was increased by use of antithrombotic agents. These results suggest that patients in Japan who require hematoma evacuation due to symptom exacerbation tend to be treated with reversal agents. Although it is difficult to assess the efficacy of reversal therapy from this study, earlier treatment with reversal agents before the occurrence of acute exacerbation may be useful to improve outcomes.

Code ICH: A Call to Action

Intracerebral hemorrhage is the most serious type of stroke, leading to high rates of severe disability and mortality. Hematoma expansion is an independent predictor of poor functional outcome and is a compelling target for intervention. For decades, randomized trials aimed at decreasing hematoma expansion through single interventions have failed to meet their primary outcomes of statistically significant improvement in neurological outcomes. A wide range of evidence suggests that ultra-early bundled care, with multiple simultaneous interventions in the acute phase, offers the best hope of limiting hematoma expansion and improving functional recovery. Patients with intracerebral hemorrhage who fail to receive early aggressive care have worse outcomes, suggesting that an important treatment opportunity exists. This consensus statement puts forth a call to action to establish a protocol for Code ICH, similar to current strategies used for the management of acute ischemic stroke, through which early intervention, bundled care, and time-based metrics have substantially improved neurological outcomes. Based on current evidence, we advocate for the widespread adoption of an early bundle of care for patients with intracerebral hemorrhage focused on time-based metrics for blood pressure control and emergency reversal of anticoagulation, with the goal of optimizing the benefit of these already widely used interventions. We hope Code ICH will endure as a structural platform for continued innovation, standardization of best practices, and ongoing quality improvement for years to come.

Management of major bleeding for anticoagulated patients in the Emergency Department: an European experts consensus statement

An increasing number of patients presenting to the emergency department (ED) with life-threatening bleeding are using oral anticoagulants, such as warfarin, Factor IIa and Factor Xa inhibitors. Achieving rapid and controlled haemostasis is critically important to save the patient's life. This multidisciplinary consensus paper provides a systematic and pragmatic approach to the management of anticoagulated patients with severe bleeding at the ED. Repletion and reversal management of the specific anticoagulants is described in detail. For patients on vitamin K antagonists, the administration of vitamin K and repletion of clotting factors with four-factor prothrombin complex concentrate provides real-time ability to stop the bleeding. For patients using a direct oral anticoagulant, specific antidotes are necessary to reverse the anticoagulative effect. For patients receiving the thrombin inhibitor dabigatran, treatment with idarucizamab has been demonstrated to reverse the hypocoagulable state. For patients receiving a factor Xa inhibitor (apixaban or rivaroxaban), andexanet alfa is the indicated antidote in patients with major bleeding. Lastly, specific treatment strategies are discussed in patients using anticoagulants with major traumatic bleeding, intracranial haemorrhage or gastrointestinal bleeding.

Development of Cloud-Based Telemedicine Platform for Acute Intracerebral Hemorrhage in Gangwon-do : Concept and Protocol

We aimed to develop a cloud-based telemedicine platform for patients with intracerebral hemorrhage (ICH) at local hospitals in rural and underserved areas in Gangwon-do using artificial intelligence and non-face-to-face collaboration treatment technology. This is a prospective and multi-center development project in which neurosurgeons from four university hospitals in Gangwondo will participate. Information technology experts will verify and improve the performance of the cloud-based telemedicine collaboration platform while treating ICH patients in the actual medical field. Problems identified will be resolved, and the function, performance, security, and safety of the telemedicine platform will be checked through an accredited certification authority. The project will be carried out over 4 years and consists of two phases. The first phase will be from April 2022 to December 2023, and the second phase will be from April 2024 to December 2025. The platform will be developed by dividing the work of the neurosurgeons and information technology experts by setting the order of items through mutual feedback. This article provides information on a project to develop a cloud-based telemedicine platform for acute ICH patients in Gangwon-do.

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.

Hematoma expansion in intracerebral hemorrhage - the right target?

BACKGROUND

The avoidance of hematoma expansion is the most important therapeutic goal during acute care of patients with intracerebral hemorrhage. Hematoma expansion occurs in up to 20-40% of patients and leads to poorer patient outcome in one of the most severe sub-types of stroke.

MAIN TEXT

At current, randomized controlled trials have failed to provide evidence for interventions that effectively improve functional outcome in patients with intracerebral hemorrhage. Hence, hematoma expansion may serve as important surrogate target that appears causally linked with a poorer prognosis. Therefore, reduction of hematoma expansion rates will eventually translate to improved patient outcome overall. Recent years have shed light on the importance of early and aggressive treatment in order to reduce the risk for hematoma expansion in these patients. Time measures and imaging markers have been identified that may allow patient selection at very high risk for hematoma expansion.

CONCLUSIONS

Refinements in patient selection may increase chance for randomized trials to show true benefit. Therefore, this current review article will critically evaluate and discuss available evidence associated with hematoma expansion in patients with intracerebral hemorrhage.

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.

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

Background

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

Objectives

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

Methods

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

Results

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

Conclusion

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

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.

Direct Oral Anticoagulants: Laboratory Challenges and Antidotes

The use of direct oral anticoagulants (DOACs) is increasing in patients needing treatment of venous thromboembolism (VTE) and stroke prevention in atrial fibrillation (SPAF). This is due to the net clinical benefit in comparison to vitamin K antagonists (VKAs). The rise in DOAC use is accompanied by a remarkable reduction in heparin and VKA prescriptions. However, this rapid change in anticoagulation patterns brought new challenges to patients, prescribers, laboratories, and emergency physicians. Patients have new liberties concerning nutritional habits and comedication and no longer need frequent monitoring or dose adjustments. Still, they have to comprehend that DOACs are potent anticoagulants that may cause or contribute to bleeding. Challenges for the prescriber include decision pathways for choosing the right anticoagulant and dosage for a specific patient and to change bridging practice in case of invasive procedures. Laboratory personnel are challenged by DOAC due to limited 24/7 availability of specific DOAC quantification tests and by the impact of DOAC on routine coagulation assays and thrombophilia tests. Challenges for the emergency physician result from the increasing age of DOAC anticoagulated patients, the difficulties to establish last intake of DOAC type and dosage, to interpret coagulation test results in emergency situations, and to make decisions for or against DOAC reversal strategies in acute bleeding or urgent surgery. In conclusion, although DOACs make long-term anticoagulation safer and more convenient for patients, DOACs pose challenge to all healthcare providers involved in anticoagulation decisions. The key to correct patient management and optimal outcome therefore lies in education.

Intrakranielle Blutungen unter oraler Antikoagulation

Bei intrakraniellen Blutungen unter einer oralen Antikoagulation (OAK) mit Vitamin-K-Antagonisten (VKA) oder direkten oralen Antikoagulanzien (DOAK) besteht innerhalb der ersten Stunden das Risiko einer frühen Hämatomexpansion mit konsekutiver klinischer Verschlechterung. Zur Antagonisierung der antikoagulatorischen Wirkung von VKA stehen die i. v. Gabe von Vitamin K (10 mg) sowie von Prothrombin-Komplex-Konzentrat (PPSB, mindestens 30 U/kgKG) zur Verfügung. Bei Blutung unter dem Thrombininhibitor Dabigatran kann die Gabe des humanisierten monoklonalen Antikörperfragments Idarucizumab (2 × 2,5 g i. v.) erwogen werden. Es bindet spezifisch und mit hoher Affinität an Dabigatran und unterbindet dessen antikoagulatorische Wirkung. Für die Antagonisierung der Faktor-Xa-Hemmer Apixaban und Rivaroxaban steht Andexanet alfa zur Verfügung. Dies ist ein rekombinant hergestellter und biologisch inaktiver Faktor Xa, der als Antidot Faktor-Xa-Hemmer unselektiv bindet und ihre Wirkung neutralisiert.

Patient factors associated with receiving reversal therapy in oral anticoagulant-related intracerebral hemorrhage

BACKGROUND

We aimed to describe baseline characteristics of patients with oral anticoagulant-related intracerebral hemorrhage (OAC-ICH) in Sweden and to identify predictive variables associated with receiving hemostatic treatment in the event of OAC-ICH.

METHODS

We performed an observational study based on data from Riksstroke and the Swedish Causes of Death Register to define baseline characteristics of patients with OAC-ICH who received reversal treatment compared with patients who did not receive reversal treatment during 2017-2019. Predictive analysis was performed using multivariable logistic regression to identify odds ratios for factors associated with receiving OAC reversal treatment.

RESULTS

We included 1902 patients ((n = 1146; OAC reversal treatment) (n = 756; no OAC reversal treatment)). The proportion of non-Vitamin K oral anticoagulant associated ICH (NOAC-ICH) patients who received reversal treatment was 48.4% and the proportion of Vitamin K antagonist-associated ICH (VKA-ICH) patients was 72.9%. Factors associated with a lower odds of receiving reversal treatment were increased age (OR = 0.98; 95% CI: 0.96-0.99), previous stroke (OR = 0.78; 95% CI: 0.62-0.98), comatose LOC (OR = 0.36;95%CI: 0.27-0.48; ref. = alert), pre-stroke dependency (OR = 0.72; 95% CI: 0.58-0.91), and NOAC treatment (OR = 0.34; 95% CI: 0.28-0.42). Care at a university hospital was not associated with higher odds of receiving reversal treatment compared to treatment at a county hospital.

CONCLUSION

Treatment with a reversal agent following OAC-ICH was related to several patient factors including type of OAC drug. We identified that only 48% of patients with NOAC-ICH received hemostatic treatment despite an increase in these cases. Further studies are required to guide the use of reversal therapies more precisely, particularly in NOAC-ICH.

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.

Increased Prognostic Yield by Combined Assessment of Non-Contrast Computed Tomography Markers of Antithrombotic-Related Spontaneous Intracerebral Hemorrhage Expansion

Background and aims: The utility of proposed non-contrast computed tomography (NCCT) markers for the prediction of hematoma expansion in patients with antithrombotic-related spontaneous intracerebral hemorrhage (ICH) is limited. Additionally, there is significant overlap between different suggested ICH shape and density markers. Methods: We assessed the prognostic yield for hematoma expansion of a combined score incorporating features of ICH shape irregularity (satellite sign and/or Barras score ≥ 3), heterogeneous ICH density (swirl sign and/or Barras score ≥ 3) on baseline NCCT and timing from ICH onset to NCCT. Results: We evaluated data from 79 patients with antithrombotic-related spontaneous ICH (32% with hematoma expansion). Swirl (84% vs. 39%) and satellite signs (20% vs. 7%) on baseline NCCT were significantly more prevalent (p < 0.001) in patients with hematoma expansion. Patients with hematoma expansion had more irregular and heterogeneous bleeds on baseline NCCT scans, as quantified by higher (p < 0.001) Barras shape (4 (4−5) vs. 3 (2−4)) and density scores (4 (3−5) vs. 2 (1−3)), respectively. The overall diagnostic yield of the combined score (area under the curve: 0.86, 95%CI: 0.78−0.94) significantly outperformed (p < 0.001) the diagnostic yield of each individual marker. Scores of 4 or 5 in the combined score were associated with a sensitivity of 60.0%, specificity of 90.7%, overall diagnostic accuracy of 81.0%, positive likelihood ratio (LR) of 6.48, negative LR of 0.44, positive predictive value (PV) of 0.76 and negative PV of 0.83. Conclusion: Combined NCCT marker assessment seems to increase the prognostic accuracy for hematoma expansion in antithrombotic-related spontaneous ICH patients.

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.