Impact of Left Ventricular Venting on Acute Brain Injury in Patients with Cardiogenic Shock: An Extracorporeal Life Support Organization Registry Analysis.

BACKGROUND

While left ventricular (LV) venting reduces LV distension in cardiogenic shock patients on venoarterial extracorporeal membrane oxygenation (VA-ECMO), it may also amplify risk of acute brain injury (ABI). We investigated the hypothesis that LV venting is associated with increased risk of ABI. We also compared ABI risk of the two most common LV venting strategies, percutaneous microaxial flow pump (mAFP) and intra-aortic balloon pump (IABP).

METHODS

The Extracorporeal Life Support Organization registry was queried for patients on peripheral VA-ECMO for cardiogenic shock (2013-2024). ABI was defined as hypoxic-ischemic brain injury, ischemic stroke, or intracranial hemorrhage. Secondary outcome was hospital mortality. We compared no LV venting with 1) LV venting, 2) mAFP, and 3) IABP using multivariable logistic regression. To compare ABI risk of mAFP vs. IABP, propensity score matching was performed.

RESULTS

Of 13,276 patients (median age=58.2, 69.9% male), 1,456 (11.0%) received LV venting (65.5% mAFP and 29.9% IABP), and 525 (4.0%) had ABI. After multivariable regression, LV-vented patients had increased odds of ABI (adjusted odds ratio (aOR)=1.76, 95% CI=1.29, 2.37, p<0.001) but no difference in mortality (aOR=1.08, 95% CI=0.91-1.28, p=0.39) compared to non-LV-vented patients. In the propensity- matched cohort of IABP (n=231) vs. mAFP (n=231) patients, there was no significant difference in odds of ABI (aOR=1.35, 95%CI=0.69-2.71, p=0.39) or mortality (aOR=0.88, 95%CI=0.58-1.31, p=0.52).

CONCLUSIONS

LV venting was associated with increased odds of ABI but not mortality in patients receiving peripheral VA-ECMO for cardiogenic shock. There was no difference in odds of ABI or mortality for IABP vs. mAFP patients.

CLINICAL PERSPECTIVE: In patients receiving peripheral venoarterial extracorporeal membrane oxygenation (VA-ECMO) for cardiogenic shock, left ventricular venting is associated with increased odds of acute brain injury (ABI) but not mortality. However, mode of venting-intra-aortic balloon pump (IABP) or percutaneous microaxial flow pump (mAFP)-does not appear to impact either odds of ABI or mortality. These findings highlight a link between venting strategies and neurological outcomes in this high-risk population. Clinicians must weigh the benefits of venting against ABI risk when managing neurocritically ill patients, though our findings provide reassurance clinicians that both IABP and mAFP may offer comparable neurologic safety profiles.