Anticoagulant management for transition from failed thrombolysis to extra-corporeal membrane oxygenation in patients with high-risk pulmonary embolism: A thoughtful approach

Acute venous thromboembolism represents a spectrum of clinical syndromes of which high-risk pulmonary embolism (PE) with consecutive right ventricular failure and cardiogenic shock (CS) is the most severe pre-sentation. First-line treatment options are surgical pulmonary embolectomy, systemic thrombolysis or catheter -based therapies. The role of mechanical circulatory support with veno-arterial extracorporeal membrane oxygenation (V-A-ECMO) is multifarious in this setting and can be considered as either a bridge to pulmonary artery reperfusion by any of the aforementioned options or as salvage bridge intervention for patients in re-fractory CS after failure of another treatment. In the subpopulation of patients that are placed on V-A-ECMO after failed thrombolysis, the mortality rates are among the highest, partially due to the high rates of bleeding events. The challenges in the interpretation of anticoagulant monitoring and, consequently, the titration of anti-coagulation at least contribute to this high mortality. Here, we discuss the strengths and limitations of different anticoagulant parameters in this setting and propose an approach based on monitoring of Heparin anti-factor Xa (anti-Xa) assay and activated partial thromboplastin time (APTT) in parallel to drive unfractionated heparin (UFH) titration in patients with high-risk PE after fibrinolysis during the first 24 h on V-A-ECMO.