A Case of Andexanet Alfa Induced Heparin Resistance in Emergent Aortic Surgery: Successful Anticoagulation Management Using Antithrombin Administration.

Andexanet alfa (AnAl) is utilized for the urgent reversal of direct oral anticoagulants (DOACs) in cases of severe bleeding. While the guidelines from the Society of Thoracic Surgeons recommend AnAl for urgent cardiac surgery in patients treated with DOACs, concerns persist regarding the potential of AnAl to induce heparin resistance. This report details the case of an 85-year-old woman diagnosed with acute type A aortic dissection, who received AnAl due to prior edoxaban use. During the emergent aortic surgery, she exhibited heparin resistance following the administration of unfractionated heparin (UFH). The administration of antithrombin III (ATIII) significantly influenced activated clotting times, facilitating successful surgery while maintaining adequate anticoagulation. This case underscores the importance of cautious management of AnAl-induced heparin resistance during critical surgeries, emphasizing the role of ATIII supplementation for effective anticoagulation.