Real-world outcomes of unfractionated heparin plus antithrombin concentrate versus bivalirudin in adult patients undergoing extracorporeal membrane oxygenation

Background Extracorporeal membrane oxygenation (ECMO) provides life support to patients undergoing cardiopulmonary surgeries when other interventions are ineffective. Unfractionated heparin (UFH) is routinely used during ECMO due to increased risk of thrombosis. However, in some cases, like antithrombin deficiency, UFH is not efficacious, and heparin resistance (HR) can develop. There is considerable confusion about HR and what additional management strategies should be taken. Objectives This study compared clinical and economic outcomes associated with antithrombin concentrate (ATc) + UFH versus bivalirudin in adult patients undergoing ECMO. Methods This retrospective cohort study used data from the 2014-2023 TriNetX database and the 2018-2021 Premier Healthcare Database. Adult patients treated with ATc + UFH or bivalirudin within 3 days of ECMO initiation who did not undergo cardiopulmonary bypass (CPB) or coronary artery bypass grafting (CABG) during their ECMO hospital stay were identified. Propensity score matching was performed to balance the groups. Thromboembolic events, bleeding events, heparin-induced thrombocytopenia, hospital mortality, length of stay, and total hospital cost were compared. Results A total of 1601 patients (276 ATc + UFH, and 1352 bivalirudin) were identified from TriNetX, and 1592 (264 ATc + UFH, and 1528 bivalirudin) from Premier. ATc + UFH was associated with lower odds of thrombotic and bleeding events compared to bivalirudin only. Length of stay and total hospital costs trended lower for patients prescribed antithrombin and UFH. Conclusions Antithrombin + UFH may be a preferable option for managing ECMO patients, particularly those with heparin resistance.