Andexanet alfa and heparin resistance in cardiac surgery: Experiences and risks associated with the reversal of direct oral anticoagulants

In their case report ‘Andexanet alfa in acute aortic syndrome: first UK experience’, Al-Attar et al. describe their experiences with Andexanet alfa (AA) in the context of emergency surgeries for type A aortic dissections [1]. In 3 patients, AA was used, with 2 patients receiving it after cardiopulmonary bypass (CPB) and 1 patient receiving it pre-hospital, thereby before CPB. While the procedure was complication free and hemostasis was ensured in the 2 patients who received AA post-CPB, achieving suitable ACT despite repetitive heparin administrations in the patient with pre-hospital AA administration proved difficult. Eventually, clots were even found in the venous reservoir of the heart–lung machine. Direct oral anticoagulants (DOACs) prevent and treat thrombosis and embolism. They have fewer interactions with food and drugs and require fewer blood tests compared to vitamin K antagonists. Dabigatran, the first DOAC and a direct thrombin inhibitor, was approved in Europe in 2008 and the USA in 2010. Direct factor Xa inhibitors rivaroxaban and apixaban were approved in Europe in 2008 and 2011, respectively, and in the USA in 2011 and 2012. Additional DOACs like edoxaban and betrixaban have since become available.