Association Between Blood-Brain Barrier Disruption and Stroke-Associated Pneumonia in Acute Ischemic Stroke Patients After Endovascular Therapy: A Retrospective Cohort Study.

Background: Stroke, particularly due to large vessel occlusion (LVO), is a major cause of mortality and disability globally. Endovascular therapy (ET) significantly improves outcomes for acute ischemic stroke (AIS) patients, but complications such as stroke-associated pneumonia (SAP) increase mortality and healthcare costs. This study investigates the association between blood-brain barrier (BBB) disruption and the increased risk of SAP and explores the relationship between BBB disruption and medium-term functional outcomes.

Methods: The retrospective cohort study was performed on AIS patients enrolled between January 2019 to February 2023 who underwent ET. Patients were divided into two groups: BBB disruption and without BBB disruption. Multiple logistic regression model was conducted to measure the association between BBB disruption and SAP. Mediation analysis was used to estimate the potential mediation effects on the associations of BBB disruption with SAP. A restricted cubic spline (RCS) regression model was used to further outline the connection between the highest CT value of hyperattenuated lesions areas and the risk of SAP.

Results: The study included 254 patients who underwent endovascular therapy, with 155 patients in the BBB disruption group (exposure) and 99 patients in the without BBB disruption group (control). Multiple logistic regression analysis revealed a significantly increased risk of SAP in patients with BBB disruption (OR = 2.337, 95% CI: 1.118-4.990, p = 0.025). Furthermore, mediation analysis suggested that this association may be partly due to malignant cerebral oedema and haemorrhagic transformation. The study found an inverse L-shaped dose-response relationship between the maximum CT values of BBB disruption areas and the incidence of SAP. SAP partially mediated the association between BBB disruption and 3-month poor functional outcome.

Conclusion: BBB disruption are a potential risk factor for SAP. BBB disruption may affect short- and medium-term prognosis of patients after ET in part through SAP.