Extracorporeal membrane oxygenation (ECMO) contributes to coagulopathy, necessitating systemic anticoagulation to prevent thrombosis. Traditionally, unfractionated heparin (UFH) has been the anticoagulant of choice, however, due to many inadequacies new evidence suggests benefit with the use of direct thrombin inhibitors. This retrospective cohort sought to evaluate the safety and efficacy of bivalirudin compared to UFH in ECMO patients. Primary endpoints included incidence of bleeding and thrombosis. Percent time in therapeutic range (TR), time to achieve TR and number of dose titrations required to maintain TR were calculated to assess efficacy of institutional protocols. Overall incidence of thrombosis was low, with one event in the bivalirudin group and no events in the UFH group. No difference was found in rates of bleeding between groups (6% vs. 10%, P = 0.44). Bivalirudin yielded higher percent time in TR (86% vs. 33%, P < 0.001), faster time to TR (2 vs. 18 hr, P < 0.001) and required fewer dose adjustments to maintain TR (2 vs. 11, P < 0.001) compared to UFH. These results suggest bivalirudin and UFH are associated with similar rates of bleeding and thrombosis in patients requiring ECMO support. Our results demonstrate the favorable pharmacokinetic profile of bivalirudin, and its ability to consistently maintain TR when compared to UFH.

Background Extracorporeal membrane oxygenation (ECMO) is a potential option for the management of severe acute respiratory failure secondary to COVID-19. Conflicting the use of this therapy is the known coagulopathy within COVID-19, leading to an incidence of venous thrombotic events of 25% to 49%. To date, limited guidance is available on optimal anticoagulation strategies in this population. Objective The purpose of this study was to evaluate the utilization of a pharmacist-driven bivalirudin dosing protocol for anticoagulation in the setting of ECMO for COVID-19–associated respiratory failure. Methods This was a single-center retrospective chart review over a 9-month period of patients receiving bivalirudin while on ECMO. All patients with acute respiratory failure requiring ECMO with a positive SARS-CoV-2 polymerase chain reaction were included. Bivalirudin was dosed via aPTT monitoring after a starting dose of 0.2 or 0.3 mg/kg/h. Results There were 33 patients included in this study, all receiving mechanical ventilation. The most common starting dose of bivalirudin was 0.2 mg/kg/h, with an average time to therapeutic range of 20 hours. Compared to previous reports, rates of bleeding were low at 15.1%, and 6.1% of patients developed a new venous thromboembolic event while on ECMO. ECMO survival was 51.5%, with an ICU mortality rate of 48.5%. Conclusion and Relevance In the first published report of its use within this population, bivalirudin was found to be a viable choice for anticoagulation in those patients on ECMO for severe respiratory failure secondary to COVID-19.

Background There is considerable debate surrounding venous thromboembolism (VTE) prophylaxis in patients post coronary artery bypass grafting (CABG) procedures. The American College of Chest Physicians guidelines report weak recommendations for starting VTE prophylaxis, but provide no specific guidance regarding timing or preferred prophylactic agent. Methods This retrospective cohort study was designed to compare outcomes of post-cardiac surgery patients admitted to the cardiovascular intensive care unit (ICU) who received subcutaneous unfractionated heparin (UFH), with those who received subcutaneous enoxaparin for VTE prophylaxis. Between January 2013 and September 2017, 1085 patients were identified, and, after propensity score matching, 850 patients were selected for analysis. The primary outcomes were postoperative VTE and the occurrence of bleeding events up to 30 days postoperatively. Secondary outcomes included chest tube output, days mechanically ventilated, ICU length of stay, total hospital length of stay, and 30-day readmission rates. Results During the study period, rates of 2.03% for VTE events and 1.38% for bleeding events were reported in the entire cohort. After matching, the rates of VTE events (2.12% vs. 1.41%, p = 0.43) and bleeding events (1.18% vs. 0.94%, p = 1.00) were more frequent in the heparin group versus the enoxaparin group; these differences were not statistically significant. However, we did find a statistically significant increase in several secondary endpoints, including chest tube output, days mechanically ventilated, ICU length of stay, and total hospital length of stay, within the heparin cohort. Bleeding rates were similar to those previously published, despite the early initiation of VTE prophylaxis. Conclusions We report no statistical difference in the rates of VTE or bleeding between chemical agents, but our results suggest enoxaparin may be a preferred agent over UFH.