Abstract 194: Impact of Pre‐treatment Cerebral Microbleeds on the Outcomes of Endovascular Thrombectomy

Introduction Endovascular thrombectomy (EVT) is the gold standard treatment for patients with acute ischemic stroke (AIS) caused by large vessel occlusion (LVO), and there are several factors that can influence the outcomes of EVT in AIS‐LVO patients. We conducted this meta‐analysis to investigate the effect of cerebral microbleeds (CMBs) on the functional and safety outcomes of EVT in patients with AIS caused by LVO. Methods We followed the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) guidelines. We included observational studies that recruited AIS‐LVO patients, used susceptibility‐sensitive magnetic resonance imaging (MRI) to detect CMBs, and examined the association between them and predefined outcome events. The outcomes of interest included functional independence, revascularization success, and hemorrhagic adverse events. We conducted a meta‐analysis using the Mantel‐Haenszel method and calculated the risk ratios. Results Four studies involving 1,514 patients were included. A significant reduction in the likelihood of achieving a favorable functional outcome, as measured by the modified Rankin Scale (mRS), was observed in patients with CMBs (Risk Ratio (RR) 0.70, 95% Confidence Interval (CI): 0.53 ‐ 0.91, P=0.01). No significant differences were observed between the two groups in terms of successful revascularization (RR 0.93, 95% CI [0.74 to 1.17], P=0.51), mortality (RR 0.93, 95% CI [0.74 to 1.17], P=0.51), hemorrhagic transformation (RR 0.93, 95% CI [0.59 to 1.45], P=0.74), and parenchymal hematoma (RR 1.23, 95% CI [0.79 to 1.91], P=0.35). Conclusion The presence of CMBs significantly reduced the likelihood of achieving a favorable functional outcome after EVT in AIS‐LVO patients. However, CMBs did not impact the rates of successful revascularization, mortality, or the occurrence of various hemorrhagic complications. Future research should explore the mechanisms of this association and strategies to mitigate its impact.