Mortality and complications in low-dose vs standard-dose unfractionated heparin anticoagulation for extracorporeal membrane oxygenation: a systematic review and meta-analysis
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; I2 = 38%). Patients receiving LD anticoagulation had significantly lower risk of ICH (RR, 0.29; 95% CI, 0.13-0.63, I2 = 0%), while the risk of major bleeding events was not significantly different between groups (RR, 0.78; 95% CI, 0.51-1.21; I2 = 55%). LD anticoagulation did not significantly increase the risk of oxygenator changes (RR, 1.54; 95% CI, 0.94-2.53; I2 = 42%) or systemic thrombotic events (RR, 1.27; 95% CI, 0.88-1.84; I2 = 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.