Abstract Number: Esoc2026a1635 Effect of Core, Hypoperfusion, and Mismatch on the Efficacy and Safety of Endovascular Therapy in Posterior Cerebral Artery Occlusion Stroke: A Subanalysis of the Plato-Study

Abstract Background and aims The optimal treatment strategy for acute ischemic stroke (AIS) with isolated posterior cerebral artery occlusion (iPCAO) remains unclear. We aimed to assess whether the association between endovascular treatment (EVT) and outcomes in iPCAO-AIS is modified by baseline perfusion imaging parameters. Methods From the international, multicenter, retrospective PLATO-registry (01/2015-05/2025), we included consecutive iPCAO-AIS with baseline CT-/MR-perfusion imaging from 36 centers. We evaluated heterogeneity in the association between EVT and outcomes compared to medical management (MM), according to baseline perfusion parameters using multivariable regression models with propensity score weighting and perfusion volume-treatment interaction terms. Results Among 443 patients (median age 74 years, 41.8% women), 176 underwent EVT. Core volume significantly modified the association between EVT and 90-day modified Rankin Scale (mRS) distribution (Pinteraction=0.009): EVT had a higher likelihood of worse mRS shift than MM in patients with larger core volume, while mRS distribution was similar between treatment groups in patients with low core volume. While no perfusion parameters modified the association of EVT with excellent (mRS 0-1) or good functional outcomes (mRS 0-2), core volume modified the association between EVT and mortality (Pinteraction=0.021), with higher mortality with EVT compared to MM at larger volumes. Higher hypoperfusion volumes modified the risk of symptomatic intracranial hemorrhage associated with EVT (Pinteraction=0.044), with similar risk to MM at small hypoperfusion volumes, but higher with EVT than MM at larger hypoperfusion. Conclusions Baseline core volume modifies the association between EVT and clinical outcomes in AIS with iPCAO, primarily identifying patients at increased risk of harm with EVT. Conflict of interest "Norma J. Diel: nothing to disclose", "Davide Strambo: nothing to disclose", "Patrik Michel: nothing to disclose", "Mohamad Abdalkader: nothing to disclose", "Muhammad M. Qureshi: nothing to disclose", "Anh Nguyen: nothing to disclose", "Marta Olive-Gadea: nothing to disclose", "Daniel Strbian: nothing to disclose", "Simon Nagel: nothing to disclose“, "Thanh N. Nguyen: nothing to disclose" Figure 1 - belongs to Results