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

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

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

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.

Reversal of direct oral anticoagulants: guidance from the SSC of the ISTH

The currently approved direct oral anticoagulants (DOACs) are increasingly used in clinical practice. Although serious bleeding risks are lower with DOACs than with vitamin K antagonists, bleeding remains the most frequent side effect. Andexanet alfa and idarucizumab are the currently approved specific reversal agents for oral factor (F)Xa inhibitors and dabigatran, respectively. Our prior guidance document was published in 2016, but with more information available on the utility and increased use of these reversal agents and other bleeding management strategies, we have updated this International Society on Thrombosis and Haemostasis guidance document on DOAC reversal. In this narrative review, we compare the mechanism of action of specific and nonspecific reversal agents, review the clinical data supporting their use, and provide guidance on when reversal is indicated. In addition, we briefly discuss the reversal of oral FXIa inhibitors, a new class of DOACs currently under clinical development.

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

BACKGROUND

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

METHODS

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

CONCLUSIONS

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

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; unique identifier: NCT06147830.

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.

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

OBJECTIVE

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

METHODS

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

ENDPOINT

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

RESULTS

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

CONCLUSIONS

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

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.

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.

Andexanet Alfa: What We Have Learned from Clinical Trials and Real-World Data

Andexanet alfa is a specific reversal agent for factor Xa inhibitors with immediate reversal of their anticoagulant effect. Andexanet alfa is currently approved for use in patients treated with rivaroxaban and apixaban who have life-threatening or uncontrolled bleeding. New data from both controlled clinical trials and real-world experience are continuously being published, providing greater insight into the clinical characteristics of the drug, such as efficacy and safety. It is worth considering that andexanet alfa could be of benefit in a variety of different clinical scenarios where patients receiving treatment with apixaban and rivaroxaban (and endoxaban) have life-threatening conditions. These different clinical scenarios, which range from pre-treatment of urgent surgery, especially neurosurgical interventions, and concomitant use of andexanet alfa and prothrombin complex concentrate to onset of bleeding more than 6 h prior to admission, should be clarified as well as the issue of "low/high" dose of andexanet alfa and the need for baseline anti-Xa inhibitor levels measured by point-of-care testing. Finally, management of patients at high risk of thrombosis or recent arterial/venous thrombotic events needs to be further explored. In this current opinion, we address these urgent questions in the light of recent literature and clinical trial data.

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.