Bivalirudin as Therapeutic Anticoagulation in COVID-19 Patients on ECMO

ABSTRACT

Due to the inherent thrombotic risk associated with the ECMO circuit, therapeutic anticoagulation is recommended. While unfractionated heparin is commonly used due to wide availability, the use of bivalirudin, a direct thrombin inhibitor, is gaining popularity. The benefits of bivalirudin over heparin include Relatively organ-independent metabolism, inhibition of fibrin-bound and freely circulating thrombin, rapid clearance, and less resistance. Early reports in the COVID-19 pandemic suggest a hypercoagulable state. Particular attention should be paid to adequate anticoagulation in the high-risk patients with SARs-CoV-2 on ECMO support. To date, there are few reports discussing the use of bivalirudin in COVID ECMO patients. Bivalirudin is the anticoagulation of choice for the maintenance of patients on ECMO at our institution. We conducted a retrospective analysis of the first 20 patients with COVID that required ECMO support. Data was collected on outcomes related to hemostasis. Standard protocol for ECMO patients includes screening duplex ultrasound at regular intervals following decannulation to evaluate for thromboembolism. Three patients did not receive screening due to terminal weans. Of the remaining 17 patients, 7 had confirmed acute venous thromboembolism. Four patients had hemorrhage requiring intervention;two cases of epistaxis, one intra-abdominal bleeding, and one cannulation site bleeding. One patient developed nonfatal intracranial hemorrhage that did not require intervention. Only two patients developed renal failure requiring temporary renal replacement therapy. This is in comparison to the 24% rate noted in the ELSO COVID-19 database. Our findings suggest bivalirudin is an alternative to heparin for appropriate COVID ECMO patients.