Bleeding risk and concomitant use of microaxial flow pump in patients with cardiogenic shock receiving VA-ECMO

Background The management of bleeding complications in patients receiving mechanical circulatory support is a critical issue. However, limited data are available on the bleeding risks associated with the concomitant use of a microaxial flow pump (mAFP) in patients supported by venoarterial extracorporeal membrane oxygenation (VA-ECMO). Purpose We aimed to investigate whether the addition of mAFP increases the risk of bleeding complications in cardiogenic shock (CS) patients receiving VA-ECMO. Methods We analyzed a single-center cohort of 280 patients who received VA-ECMO for CS between April 1, 2014, and December 31, 2023. The association between concomitant mAFP use and the risk of various bleeding events was evaluated. Results Among the 280 patients, the median age was 64 years, 75% were male, and 44% received concomitant mAFP. During hospitalization (median duration: 19 [3–55] days), 156 (56%) bleeding events were observed, including gastrointestinal bleeding in 36 (13%), access site bleeding in 88 (31%), and intracranial bleeding in 24 (9%). Most bleeding events occurred in the early phase after VA-ECMO initiation (Figure 1). Patients with concomitant mAFP had a significantly higher incidence of composite bleeding events (adjusted odds ratio [aOR]: 3.7, 95% confidence interval [CI]: 2.2–6.4; p < 0.001) compared to those without. The increased bleeding risk associated with mAFP was particularly present in gastrointestinal bleeding (aOR: 5.2, 95% CI: 2.2–11.9; p < 0.001) and access site bleeding (aOR: 3.9, 95% CI: 2.2–6.8; p < 0.001), while no significant association was observed for intracranial bleeding (aOR: 1.3, 95% CI: 0.6–3.2; p = 0.5) (Figure 2). Conclusions In CS patients receiving VA-ECMO, concomitant mAFP use was a strong risk factor for bleeding complications. The impact of mAFP on bleeding risk varied by bleeding site.