To evaluate the safety and efficacy of late-window endovascular treatment (EVT) in patients with acute ischemic stroke due to large vessel occlusion (LVO-AIS) across different etiological subtypes.

A retrospective analysis was conducted involuing 229 LVO-AIS patients who underwent late-window EVT at Linyi People's Hospital from December 2019 to June 2021. Collateral circulation was compared between large-artery atherosclerosis (LAA) and cardioembolism (CE) subtypes. Vascular recanalization status was assessed using the modified thrombolysis in cerebral infarction (mTICI) scale, and 90-day functional outcomes were evaluated with the modified Rankin scale (mRS). Safety endpoints included symptomatic intracranial hemorrhage (sICH) and 90-day mortality. Binary Logistic regression was performed to identify independent predictors of 90-day functional outcomes.

(1) No significant differences in efficacy or safety outcomes were observed between LAA and CE groups (all P>0.05). (2) In the LAA group, patients with favorable outcomes exhibited lower platelet distribution width, a reduced incidence of hyperdense vessel sign, lower baseline National Institutes of Health stroke scale (NIHSS) scores, lower Alberta stroke program early CT score (ASPECTS), and fewer sICH or cerebral herniation events compared to those with unfavorable outcomes. Additionally, shorter puncture-to-recanalization time, higher rates of conscious state, and successful recanalization were significantly associated with favorable outcomes (P<0.05). Multivariate analysis identified lower baseline NIHSS (OR=1.104, 95%CI: 1.013-1.202, P=0.024), conscious state (OR=0.054, 95%CI: 0.018-0.162, P<0.001), and shorter puncture-to-recanalization time (OR=1.046, 95%CI: 1.027-1.066, P<0.001) as independent predictors of favorable outcomes. In the CE group, favorable outcomes were associated with conscious state, alcohol use history, lower baseline NIHSS scores, and shorter puncture-to-recanalization time (P<0.05). Conscious state (OR=0.054, 95%CI: 0.003-0.961, P=0.047) and shorter puncture-to-recanalization time (OR=1.107, 95%CI: 1.016-1.207, P=0.021) independently predicted favorable outcomes.

(1) Late-window EVT demonstrates comparable safety and efficacy for both CE and LAA subtypes of LVO-AIS. (2) Conscious state and puncture-to-recanalization time are independent prognostic factors for LAA and CE subtypes, while baseline NIHSS score specifically predicts outcomes in LAA patients.