Abstract
BACKGROUND: Controversies exist in anticoagulation practices in extracorporeal membrane oxygenation (ECMO). It is uncertain whether the intensity of anticoagulation affects ECMO outcomes. OBJECTIVES: To conduct a meta-analysis to determine whether anticoagulation intensity affects ECMO outcomes. METHODS: The Medical Literature Analysis and Retrieval System Online, Embase, and Central Register of Controlled Trials' databases were searched from inception to October 2024 for trials comparing the use of low-dose (LD) and standard-dose unfractionated heparin anticoagulation in patients on ECMO. The primary outcome was short-term mortality. Secondary outcomes included major bleeding events, intracranial hemorrhage (ICH), oxygenator changes, systemic thrombotic events, and ECMO duration. Data were pooled using a random-effects meta-analysis. The risk-of-bias was assessed using the Cochrane Risk-of-Bias 2 tool for randomized controlled trials and the Risk-of-Bias in Non-Randomized Studies of Interventions for nonrandomized controlled trials. RESULTS: Seven studies with 619 patients were included. LD anticoagulation was associated with significant reduction in the relative risk (RR) of mortality compared to standard-dose anticoagulation (RR, 0.69; 95% CI, 0.52-0.91; I (2) = 38%). Patients receiving LD anticoagulation had significantly lower risk of ICH (RR, 0.29; 95% CI, 0.13-0.63, I (2) = 0%), while the risk of major bleeding events was not significantly different between groups (RR, 0.78; 95% CI, 0.51-1.21; I (2) = 55%). LD anticoagulation did not significantly increase the risk of oxygenator changes (RR, 1.54; 95% CI, 0.94-2.53; I (2) = 42%) or systemic thrombotic events (RR, 1.27; 95% CI, 0.88-1.84; I (2) = 0%). CONCLUSION: This meta-analysis suggests that LD unfractionated heparin anticoagulation is associated with significantly better survival and a lower risk of ICH without an increase in the risk of thrombotic events. LD anticoagulation should be considered a reasonable strategy in ECMO.