Anticoagulation management for veno-venous ECMO in COVID-19 patients: argatroban as rescue therapy in heparin-associated thrombocytopenia

Background Extracorporeal Membrane Oxygenation (ECMO) has been widely used in the treatment of COVID-19 acute respiratory distress syndrome. The use of anticoagulation during ECMO support remains a topic of debate. The primary aim of this study is to demonstrate the safety and efficacy of using argatroban as an anticoagulant instead of heparin in patients with heparin-associated thrombocytopenia. Methods Forty patients were enrolled and initially treated with unfractionated heparin for anticoagulation during ECMO composing the UFH group. Twenty-one of these patients experienced a drop in platelet count to below 100,000 cells/mm3, tested negative for IgG anti PF4/Heparin, and anticoagulation was switched to argatroban composing the ARG group. Hemorrhagic events were recorded along with blood chemistry parameters. Results Bleedings were significantly more frequent in UFH group than in ARG group (58/401 days vs 21/648 days). No significant differences were observed in hemorrhagic episodes for each bleeding site, except for tracheal stoma. No differences in activated partial thromboplastin time (aPTT) values were found between the two groups. Linear regression analysis revealed that the platelet count on day 5 was correlated with the initial platelet count but not with the type of anticoagulant used. Linear regression analysis in both groups showed a correlation between the duration of ECMO support and intensive care unit stay for median aPTT and median platelet count. Furthermore, no major systemic thrombotic events or circuit clotting were observed in this patient cohort. Conclusions Argatroban seems to be safe in patients with persistent heparin-associated thrombocytopenia undergoing ECMO.