Predictors of functional outcome at 3 months in ischemic stroke patients with discharge disability following endovascular therapy: a multi-center observational cohort study of 836 patients.

BACKGROUND: Endovascular therapy (EVT) is the standard of care for acute ischemic stroke due to large vessel occlusion. While predictors of 90-day functional outcome are well-established, the determinants of functional recovery remain less clearly defined in the post-discharge period for patients with initial disability. We aimed to identify the predictors of functional outcome at 3 months in patients who underwent EVT and were discharged with an unmet need for recovery (modified Rankin scale (mRS) score > 2). METHODS: A multi-center, observational cohort study was conducted using data from the Big Data Observatory Platform for Stroke in China. We included 836 patients from eight comprehensive stroke centers (August 2018 - December 2024) who received EVT, had a pre-stroke mRS of 0-2, and had an mRS > 2 at discharge. The primary outcome was functional outcome at 3 months post-EVT, defined as an mRS score of 0-2. Univariate and multivariate logistic regression analyses were performed to identify independent predictors. RESULTS: Of the 836 patients, 151 (18.1%) achieved a favorable functional outcome (mRS 0-2) at 3 months. In univariate analysis, the favorable outcome group was significantly younger, had a lower pre-EVT NIHSS, a lower rate of atrial fibrillation, a higher rate of intravenous thrombolysis, a higher rate of complete recanalization (mTICI 3), and a lower rate of parenchymal hematoma (PH) (all p < 0.05). Multivariate regression confirmed four independent predictors: younger age (aOR: 0.973; 95% CI: 0.958-0.989; p = 0.001), lower pre-EVT NIHSS (aOR: 0.940; 95% CI: 0.912-0.968; p < 0.001), complete recanalization (aOR: 1.921; 95% CI: 1.305-2.826; p = 0.001), and absence of PH (aOR: 0.424; 95% CI: 0.235-0.768; p = 0.005). CONCLUSION: A significant proportion of patients discharged with disability experiences meaningful functional recovery by 3 months post-EVT. The key predictors of this subsequent recovery are younger age, milder initial stroke severity, complete reperfusion, and the avoidance of hemorrhagic complications.