Anticoagulation Management in ECMO Patients (Ryan Rivosecchi)
ECMO Anticoagulation Strategies and MonitoringRyan discussed the use of anticoagulation and extracorporeal life support, focusing on experiences at UPMC. He outlined three main learning objectives: evaluating anticoagulation strategies for ECMO, discussing monitoring strategies, and justifying anticoagulation recommendations based on literature. Ryan emphasized the balance between bleeding and thrombotic complications in ECMO circuits, noting that despite best practices, over 50% of patients experience at least one major bleeding event while on ECMO. ECMO Anticoagulation Management ChallengesRyan discussed the challenges and considerations in managing anticoagulation for ECMO patients, highlighting the lack of strong evidence in current guidelines. He explained the pros and cons of unfractionated heparin and direct thrombin inhibitors, including their pharmacokinetics, potential side effects, and cost implications. Ryan also compared bivalirudin and argatroban, noting their differences in metabolism, dosing, and concerns about stagnant blood in ECMO circuits. He concluded by emphasizing the need for standardized anticoagulation targets and monitoring methods, while acknowledging the limitations of current studies due to small sample sizes and varying patient populations. Anti-Xa Monitoring Shows Better OutcomesRyan presented data comparing different anticoagulation strategies, highlighting that an anti-ten A monitoring protocol had a significantly lower rate of patients being over-anticoagulated compared to an Aptt-driven protocol. He noted a shift in clinical practice from using unfractionated heparin with Aptt monitoring to using bivalirudin with anti-ten A monitoring, which UPMC implemented in 2017 based on its reduced risk of heparin-induced thrombocytopenia and more predictable kinetics. Bivalirudin Superiority in ECMO PatientsRyan discussed the reasons behind the switch to bivalirudin in ECMO patients, highlighting the lack of standardization in protocols, small patient populations, and equipment changes over time. He presented the results of two UPMC studies comparing bivalirudin to unfractionated heparin in VV and VA ECMO patients. The studies, which included larger, more homogeneous patient populations, showed that bivalirudin was associated with a lower risk of in-circuit thrombosis and similar bleeding rates compared to heparin. Ryan concluded that bivalirudin is a superior anticoagulant for ECMO patients, with the benefits becoming apparent as early as 2-3 days after initiation. Bivalirudin Benefits in ECMO PatientsRyan presented data comparing bivalirudin and unfractionated heparin in ECMO patients, showing bivalirudin was associated with less bleeding and lower mortality. A study by Sealehammer from the Mayo group confirmed these findings, with a significant reduction in mortality (odds ratio 0.39) and lower circuit intervention rates in adult patients receiving bivalirudin. When combining multiple studies, including their own manuscript, the meta-analysis showed a consistent 10% decrease in mortality with bivalirudin compared to heparin. Challenges in ECMO Study DesignRyan discussed the challenges of using mortality as an endpoint in ECMO studies, noting that while it is the most reliable measure, larger sample sizes are needed. He highlighted that the Eolia study, which enrolled 250 patients over 5 years, was still below the calculated sample size of 500 patients for an 80% powered study. Ryan also explored potential mechanisms behind the observed differences in outcomes, including improved anticoagulant effects and better therapeutic ranges due to more reliable PKPD profiles. He concluded by noting the lack of consensus on optimal anticoagulation goals and the ongoing enrollment in two clinical trials. Optimizing ECMO Anticoagulation StrategiesRyan presented a detailed analysis of anticoagulation strategies in ECMO patients, focusing on a 2021 systematic review and a 2022 study by Shah and colleagues. He discussed the limited data on truly anticoagulation-free ECMO runs and the risks of bleeding and thrombotic events. The review found that anticoagulation-free ECMO was associated with a 30% bleed rate and a 23% thrombotic event rate. The 2022 study compared different anticoagulation levels in VV ECMO patients, finding that lower anticoagulation goals were associated with lower bleeding and thrombotic events. Ryan concluded that targeting lower anticoagulation levels might be beneficial, but more research is needed to determine the optimal balance between bleeding and thrombotic risks. ECMO Anticoagulation Management RecommendationsRyan presented his recommendations on anticoagulation management for ECMO patients. He concluded that bivalirudin is at least as safe and efficacious as unfractionated heparin, and is now used as the primary anticoagulant at his institution. Ryan also introduced a “start low and go slow” approach with a PTT goal of 61-75 for both VV and VA ECMO patients. He mentioned a new low-dose protocol for VV patients with a PTT goal of 40-60, which has shown positive results in initial trials. Ryan emphasized the importance of individualizing anticoagulation management based on each patient’s specific needs and circumstances. Bivalirudin Use in Cardiac SurgeryRyan presented a talk on the use of bivalirudin as an anticoagulant in his center, highlighting its cost-effectiveness and potential to reduce blood product usage. Walid expressed surprise at the limited use of routine anticoagulation methods in Ryan’s center and discussed the slow adoption of new practices in medicine. They agreed that while bivalirudin is promising, more randomized controlled trials are needed for wider acceptance. Ryan mentioned that his center now uses bivalirudin for most impella patients to avoid heparin products. |