The Incidence of Thrombotic Events After the Concomitant Use of Andexanet alfa and 4-Factor Prothrombin Complex Concentrate.

Limited data exists on the safety and efficacy with the concomitant use of 4 factor prothrombic complex concentrate (4F-PCC) and andexanet alfa (AA). This case series describes 7 patients at our institution who received both 4F-PCC and AA for the management of life-threatening bleeding associated with apixaban or rivaroxaban. Four patients received AA due to worsening bleeding after 4F-PCC. Of the 7 patients in this case series, 1 had a documented thrombotic event which was an acute ischemic stroke. The thrombotic event rate in our case series was similar to the incidence of thrombotic events reported with the use of AA alone. In-hospital mortality occurred in 2 of 7 patients with 1 additional patient discharged to hospice care.

[Acute internal carotid artery occlusion following administration of Andexanet alfa for the reversal of direct factor Xa inhibitors in patients with cerebral hemorrhage].

An 87-year-old woman receiving aspirin and apixaban with a history of large artery atherosclerotic stroke, and pulmonary embolism presented to the hospital for aphasia and right hemiplegia. A head CT scan showed 18-ml hematoma in the left thalamus. Low-dose Andexanet alfa was administered 84 minutes after the onset of stroke, and 10 hours and 24 minutes after the last dose of apixaban. Three hours later after admission, she had flaccid hemiplegia and became comatose. CT and CT angiography revealed occlusion of left internal carotid artery (ICA) and no evidence of hematoma expansion. Although repetitive mechanical thrombectomy resulted in recanalization (modified TICI 2b), carotid ultrasound revealed the occlusion of left ICA on next day. On day 7, she died of brain herniation following extensive cerebral infarction. It has been reported that some patients did experience thrombotic events after administration of Andexanet alfa. Our case illustrates that even large vessel occlusion might occur after intravenous injection of Andexanet alfa. Thus, careful follow-up, including cerebrovascular imaging, is required immediately after administration of Andexanet alfa.

Facial trauma with life-threatening bleeding treated by andexanet alfa administration: A case report.

Recently, anticoagulant reversal has become a treatment option for life-threatening bleeding, especially in intracranial hemorrhage. Although evidence of the beneficial efficacy of andexanet alfa accumulates in cases of intracranial hemorrhage, little is known about its effectiveness in head injuries without intracranial hemorrhage. We present the case of an 87-year-old man who suffered a stroke 1 year previously and had been taking apixaban since then, who was brought to the emergency department with facial trauma due to a fall. Upon arrival at the hospital, the patient was conscious, and his vital signs were normal; however, physical examination revealed epistaxis, and plain head computed tomography (CT) showed multiple facial fractures without intracranial hemorrhage. As epistaxis was challenging to control, upper airway obstruction developed. His percutaneous oxygen saturation (SpO2) decreased rapidly, and he underwent tracheal intubation. Contrast-enhanced head CT revealed at least two extravasations, near the anterior wall of the right maxillary sinus and from the nasal canal to the nasopharynx area. However, embolization using interventional radiology was deemed difficult. Because the bleeding did not stop, we determined the bleeding was life-threatening and uncontrollable. Therefore, we infused andexanet alfa to stop the bleeding. After infusion, hemostasis was confirmed. This case suggests the effectiveness of andexanet alfa in cases of facial trauma and extracranial bleeding difficult to stop, resulting in favorable outcomes and hemostatic effects.

Fatal drug reaction to andexanet alfa: a case report.

Andexanet alfa is a recombinant, modified factor Xa (FXa) molecule that is used for the reversal of the anticoagulant effect of oral anti-FXa anticoagulants in patients with major haemorrhage. Here, we present a case of an 85-year-old man taking rivaroxaban for atrial fibrillation, who presented with an acute, upper gastrointestinal bleed. He was stabilised with red cell transfusion and then received a 400 mg bolus of andexanet alfa. Within minutes of this, he developed chest tightness, shortness of breath, ischaemic electrocardiographic changes and then cardiac arrest from which he could not be resuscitated. The onset of symptoms was clearly temporally related to andexanet alfa administration and the differential diagnosis includes anaphylaxis with Kounis syndrome, or myocardial infarction. Although infusion site reactions have been reported and are relatively common, this is to date the first case of a fatal drug reaction andexanet alfa. This knowledge can be factored into physicians' risk-benefit decisions when treating patients with oral anti-FXa anticoagulant-associated major haemorrhage.

Andexanet Alfa for Edoxaban Reversal and Associated Thromboelastography Changes in Surgical Pulmonary Embolectomy.

Andexanet alfa neutralizes factor Xa inhibitors in critical bleeding situations. However, in cardiac surgery with cardiopulmonary bypass (CPB), heparin resistance induced by andexanet alfa should be a concern, and the lack of point-of-care monitoring of plasma concentration of factor Xa inhibitors makes it difficult to decide when to administer andexanet alfa. A 69-year-old man underwent emergency surgery for acute pulmonary thromboembolism. The patient had been on edoxaban until the day before the surgery. Withdrawal from CPB required venoarterial extracorporeal membrane oxygenation due to right heart failure, followed by severe bleeding that required massive transfusion. Despite adequate coagulation factor replacement, bleeding persisted and citrated kaolin-reaction time (CK-R) on thromboelastography (TEG) was prolonged. Administering andexanet alfa achieved excellent hemostasis without any thrombosis and normalized the prolonged CK-R of TEG. This is the first report of a change in TEG findings before and after administration of andexanet alfa in a cardiac surgery patient taking factor Xa inhibitor. Monitoring CK-R in TEG may help evaluate the anticoagulant effect of factor Xa inhibitors and the reversal effect of andexanet alfa.

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

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

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.

Perioperative risks associated with administration of andexanet alfa during emergency cardiac surgery with circulatory arrest.

This case report describes the perioperative course of a patient undergoing emergency repair of acute type A thoracic aortic dissection. Andexanet alfa was administered intraoperatively to obtain a dry operative field for right axillary artery exposure and cannulation. Andexanet alfa-induced heparin resistance resulted in cardiopulmonary bypass circuit and pericardial thrombosis requiring more than 400,000 units of unfractionated heparin and antithrombin III to overcome. Postoperatively, excessive chest tube output was observed secondary to protracted heparin rebound requiring continuous dosing of protamine. This case demonstrates the significant challenging perioperative, not just intraoperative, hazards associated with intraoperative andexanet alfa use during emergency cardiac surgery with cardiopulmonary bypass.

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.