Regional brain atrophy, white matter lesions, and functional outcome after endovascular thrombectomy for acute ischemic stroke

Background: Up to half of patients with acute ischemic stroke (AIS) achieving successful reperfusion after endovascular thrombectomy (EVT) remain dependent. Although global atrophy may influence recovery, the prognostic value of regional atrophy patterns and white matter (WM) lesions remains uncertain. Methods: We retrospectively included consecutive AIS patients achieving successful reperfusion (modified Thrombolysis in Cerebral Infarction (mTICI) 2b-3) after EVT at a comprehensive stroke center (2015-2023). Baseline CT was used to rate medial temporal atrophy (MTA), parietal atrophy (Koedam; antero-posterior index (API)), global cortical atrophy-frontal (GCA-F), and white matter lesions (Fazekas scale). The primary outcome was a composite measure of futile recanalization: functional dependence (modified Rankin Scale (mRS) >2), mRS worsening if premorbid mRS>2, or death. The secondary outcome was the ordinal shift across the mRS distribution. Associations between visual rating scales and outcomes were assessed using multivariable logistic and proportional-odds models, with sex-stratified and interaction analyses. Results: A total of 450 AIS patients (mean age 73.6±14.0 years; 53.8% females; n=406 anterior circulation) were included. In anterior circulation stroke, parietal and frontal atrophy scales were independently associated with poor outcome: Koedam (adjusted OR (aOR) 2.19, 95% CI 1.32 to 3.63), GCA-F (aOR 1.90, 95% CI 1.11 to 3.26), and API-positivity (aOR 2.27, 95% CI 1.36 to 3.81). Periventricular and basal ganglia Fazekas scores were associated with poor outcome in univariate analyses but lost significance after multivariable adjustment. Conclusions: Parietal and frontal atrophy are independently associated with the risk of futile recanalization after EVT. CT-based regional atrophy ratings could enhance individualized risk stratification and support treatment selection.