Medical and endovascular treatment for acute large vessel occlusion with mild stroke: a real-world nationwide registry

Background Endovascular therapy (EVT) is standard treatment for large vessel occlusion in patients with a National Institutes of Health Stroke Scale (NIHSS) score ≥6, but its role in mild stroke (NIHSS score <6) remains uncertain. Objective To explore the association between EVT and clinical outcomes in mild stroke. Methods This study prospectively enrolled consecutive patients with a mild stroke at 35 comprehensive stroke centers in China between January 2020 and December 2023. Patients were categorized into primary EVT (pEVT) or best medical management (BMM) groups. The primary outcome was an excellent outcome (modified Rankin Scale (mRS) score ≤1). Secondary outcomes included a good outcome (mRS score ≤2) and lowering of the mRS score. Safety endpoints were mortality and symptomatic intracranial hemorrhage. Outcomes were compared between groups using multivariable logistic regression and inverse probability of treatment weighting (IPTW). Results Finally, 307 patients were included: 117 received pEVT, and 190 received BMM. In the IPTW model, pEVT was associated with higher excellent (aOR=3.6, 95% CI 2.5 to 5.2) and good (aOR=4.0, 95% CI 2.5 to 6.6) outcomes, lower mortality (aOR=0.1, 95% CI 0.01 to 0.4), and a lower 90-day mRS (aOR=0.2, 95% CI 0.1 to 0.3), with similar sICH rates. Among the BMM group, 80 patients (42.1%) experienced early neurological deterioration (END), with 55 receiving rescue EVT (rEVT), and were still included in BMM group. In the multivariable model, the rEVT was related with higher excellent (aOR=7.2, 95% CI 1.4 to 37.9) and good (aOR=4.1, 95% CI 1.2 to 14.8) outcomes and a lower mRS (aOR=2.0, 95% CI 0.9 to 4.8). Conclusions Primary EVT significantly increases the likelihood of achieving an excellent outcome in mild stroke. Over 40% of patients with a mild stroke treated with BMM experienced END, and rEVT effectively improved the prognosis.