ABSTRACT NUMBER: ESOC2026A1504 CEREBRAL VENOUS OUTFLOW STATUS IS ASSOCIATED WITH FUTILE RECANALIZATION IN EVT-TREATED ACUTE ISCHAEMIC STROKE

Abstract Background and aims In >40% of stroke patients treated with endovascular therapy (EVT), outcomes remain poor despite successful recanalization. Imaging markers of this futile recanalization would be of value to identify stroke patients at risk of poor outcome who may benefit from additional therapy. We aimed to investigate whether features of acute imaging are associated with poor outcome in EVT-treated stroke patients with successful recanalization. Methods Acute stroke patients with anterior large vessel occlusion who achieved successful recanalization (mTICI 2b-3) post-EVT were prospectively recruited. Cerebral venous outflow, pial arterial collateral and tissue-level collateral profiles were assessed by the cortical vein opacification score (COVES), modified Tan (mTan) score on pretreatment CT angiogram and hypoperfusion intensity ratio (HIR, Tmax>10s/Tmax>6s) on CT perfusion, respectively. Poor outcomes were defined using a sliding dichotomy approach: 90-day modified Rankin score (mRS) 0-2 if prestroke mRS≤2; 0-3 if prestroke mRS is 3. Results Among 77 patients with successful recanalization, 43% had poor functional outcomes at 90 days. Compared with patients with good outcomes, those with poor outcomes had lower COVES (impaired venous outflow), whereas mTan score and HIR did not differ between groups. Multivariate regression analysis showed that COVES was a strong predictor of futile recanalization (adjusted odds ratio [95% CI]: 1.38 [1.01, 1.90]; P=0.04), independent of age, sex, NIHSS, pre-stroke mRS and tandem lesion. Conclusions Impaired cerebral venous outflow on pre-EVT imaging is associated with futile recanalization post-EVT. The determinants predisposing to impaired venous outflow in acute stroke are of interest as targets to further improve stroke outcome. Conflict of interest All authors: nothing to disclose