Objective: 

To evaluate whether systemic anticoagulation therapy affects the survival of adult patients receiving venovenous extracorporeal membrane oxygenation (VV-ECMO) for acute respiratory distress syndrome (ARDS).

Design: 

Multicenter retrospective study.

Setting: 

Twenty-four ICUs in Japan.

Patients: 

Six hundred and ninety-five patients received VV-ECMO for ARDS. Patients were divided into the anticoagulation group and the no-anticoagulation group according to whether or not they received anticoagulant therapy.

Interventions: 

None.

Measurements and Main Results: 

In the propensity score-overlap-weighted analysis, there was no significant difference in the 28-day survival (85.8% vs. 81.5%, p = 0.50) between the two groups. The 60-day survival, ECMO duration, circuit exchanges, bleeding complications, and transfusion volumes were also comparable. The anticoagulation group had a significantly higher average activated partial thromboplastin time during ECMO (51.3 s vs. 39.3 s, p < 0.01). These findings remained consistent in the sensitivity analysis using inverse probability of treatment weighting.

Conclusions: 

Systemic anticoagulation was not associated with short-term survival. Anticoagulation-free VV-ECMO may be feasible in patients at high-bleeding risk, but safety remains uncertain. Further studies should clarify optimal anticoagulation strategies.