Earlier endovascular therapy within 24 h of ischemic stroke is associated with attenuated systemic inflammation and better neurological recovery

Background The impact of endovascular therapy (EVT) timing within the 24-h window on tissue injury and post-ischemic inflammation in large-vessel occlusion stroke remains uncertain. Methods In a single-center prospective cohort, 216 anterior circulation large-vessel occlusion patients treated with EVT ≤ 24 h were stratified by onset-to-groin time: 0–6 h ( n = 74), 6–12 h ( n = 72), and 12–24 h ( n = 70). Serial IL-6, TNF- α , IL-1β, MMP-9, C-reactive protein, and neutrophil-to-lymphocyte ratio were measured to 72 h; reperfusion quality, final infarct volume, infarct progression, NIHSS change, and 90-day modified Rankin Scale (mRS) were compared. Results Baseline demographics, risk factors, stroke severity, and inflammatory profiles were similar across groups. Earlier EVT yielded higher mTICI 2b–3 rates and more first-pass effect, with fewer device passes and shorter procedures. Final infarct volume increased stepwise with delay (38.7, 51.3, and 64.5 mL in the 0–6 h, 6–12 h, and 12–24 h groups), paralleled by greater infarct progression. NIHSS improvement at 24 h and day 7 was greatest in the 0–6 h group, and functional independence at 90 days declined with later treatment (mRS 0–2: 64.9% vs 50.0% vs 35.7%). Symptomatic intracranial hemorrhage, procedural complications, and in-hospital mortality were low and comparable. Patients treated within 0–6 h showed blunted peaks and faster resolution of IL-6, MMP-9, C-reactive protein, and neutrophil-to-lymphocyte ratio, consistent with a more favorable neuroinflammatory trajectory. These associations remained consistent in adjusted and sensitivity analyses. Conclusion Within 24 h, earlier EVT was associated with more favorable reperfusion metrics, smaller infarct burden, lower circulating inflammatory biomarkers, and better 90-day functional outcome, without an apparent increase in major safety events. Given the observational design, these findings should be interpreted as associations rather than causal effects.