Gastrointestinal bleeding in patients on venoarterial extracorporeal membrane oxygenation: a multicenter observational study

BACKGROUND: Gastrointestinal (GI) bleeding is a common complication in patients treated with venoarterial extracorporeal membrane oxygenation (VA ECMO), yet comprehensive data on its epidemiology, clinical correlates, and prognostic implications remain inadequately characterized. METHODS: VA ECMO-treated patients at the Emergency Medicine Center of the First Affiliated Hospital with Nanjing Medical University from January 2017 to December 2023 (analysis cohort) and Intensive Care Unit of The First People's Hospital of Suqian from January 2022 to June 2024 (external validation cohort) were enrolled in this study. In the analysis cohort, stabilized inverse probability of treatment weighting (SIPTW) was used to balance baseline characteristics. Least absolute shrinkage and selection operator (LASSO) regression and binary logistic regression were used for variable selection and predictive model construction, respectively. RESULTS: The incidence of GI bleeding was 17.8% (62/349) in the analysis cohort and 12.0% (10/83) in the external validation cohort. After SIPTW adjustment, GI bleeding was significantly associated with higher 28-day mortality (HR = 2.25, 95%CI: 1.67-3.05, P < 0.001). Three independent predictors were identified: continuous renal replacement therapy (CRRT), baseline international normalized ratio (INR), and baseline calcium. The model yielded an area under the curve (AUC) of 0.797 (95%CI: 0.732-0.861) in the training set, 0.803 (95%CI: 0.706-0.900) in the internal validation set, and 0.753 (95%CI: 0.531-0.976) in the external validation cohort. CONCLUSIONS: GI bleeding is linked to elevated mortality risk in VA ECMO-treated patients. CRRT, baseline INR, and baseline calcium are independent predictors of GI bleeding in this population.