Bleeding events are common during the provision of Venoarterial ECMO (VA ECMO). Previous observational has suggested that these bleeding events are associated with an increased risk of in-hospital mortality however data on long term mortality and functional outcomes are lacking.

This multi-centre prospective observational study included patients enrolled in the EXCEL registry from February 2019 until June 2023. We collected baseline demographics, and details of ECMO support. The primary outcome was a composite of death or new disability (defined as an increase of . in the world health organization disability assessment schedule score) at 180 days after ECMO initiation. We used multivariable logistic and quantile regression adjusted for illness severity and patient characteristics and diagnosis to assess the association of bleeding with death and new disability and other functional and clinical outcomes.

The final study cohort included 704 participants, median [interquartile range IQR] age 54.5 [42 to 64] years and 259 (36.8 %) were female. Bleeding complications occurred in 312 (44.3 %) participants and 154 (22.3 %) had major bleeding. Patients with bleeding complications were more often receiving VA ECMO for peri-operative support [112 (36.4 %) vs (73 (19.3 %), p < 0.001). Patients who experienced bleeding complications were at significantly increased risk of the primary outcome at 6 months risk difference (RD) 8.95 % (95 % CI: 1.62 to 16.14). However, this finding was due to a significantly increased risk of new disability- adjusted RD 18.04 % (95 % CI: 6.22 to 29.55) rather than an increased risk of mortality in patients with bleeding compared to no bleeding [adjusted RD 5.71 % (95 % CI: −1.55 to 13.01)]. Patients with bleeding complications were also associated with an increased use of healthcare resources such as ICU length of stay and renal replacement therapy.

Bleeding increased the rate of death and disability at 6-months, but this was driven by increased disability rather mortality. Bleeding complications were associated with an increased use of healthcare resources. Prospective studies to address modifiable risk factors for bleeding complications are warranted.