Impact of Intra-Aortic Balloon Pump Support on Cerebral Blood Flow during Venoarterial ECMO

Background/Objective: Intra-aortic balloon pump (IABP) support is frequently combined with venoarterial extracorporeal membrane oxygenation (V-A ECMO) to mitigate afterload and improve cardiac performance. However, its impact on cerebral blood flow (CBF) in this setting remains unclear. We assessed the effects of IABP support on cerebral hemodynamics in patients receiving V-A ECMO. Methods: We conducted a single-center study including adults supported with femoro-femoral V-A ECMO and concomitant IABP. CBF was evaluated using transcranial Doppler ultrasonography in the middle cerebral artery during IABP standby and 1:1 assist modes. Mean flow velocity (FVm) was used as a surrogate marker of CBF. Hemodynamic parameters were recorded, and paired comparisons were performed using the Wilcoxon signed-rank test. Associations with changes in FVm were assessed by linear regression. Results: Among 48 screened patients, 21 were included. IABP support significantly reduced FVm compared with the unassisted condition (42 vs. 59 cm·s⁻¹, p<0.001). Systolic and late diastolic flow velocities decreased, while early diastolic velocity increased. Greater FVm reduction was associated with higher baseline pulse pressure and larger decreases in late diastolic velocity on IABP. Conclusions: In patients receiving V-A ECMO, IABP support was associated with reduced cerebral FVm, suggesting decreased CBF. The clinical significance of this finding warrants further investigation.