Background Acute ischemic stroke is a life-threatening condition requiring urgent intervention. For patients with large vessel occlusion (LVO), timely endovascular thrombectomy (EVT) is critical. This retrospective observational study investigates the impact of the National Institute of Health Stroke Scale (NIHSS) and onset-to-angiography time (OAT) on one-month neurological outcomes in acute ischemic stroke patients.

Methods A total of 300 acute ischemic stroke patients with LVO who underwent EVT at a tertiary medical center in Taiwan from Jan. 2015 to Dec. 2018 were included. The NIHSS-time score was calculated by multiplying the pre-EVT NIHSS score by OAT. Favorable outcomes were defined as a modified Rankin Scale (mRS) ≤ 2 at one month. Multivariate logistic regression was used to identify the association between NIHSS-time scores and outcomes, adjusting for confounders.

Results Patients with a NIHSS-time score < 4093 had significantly higher odds of achieving favorable outcomes (adjusted OR = 2.94, 95% CI = 1.56–5.56, p < 0.001). This highlights the importance of early EVT and initial stroke severity assessment in predicting recovery.

Conclusion This study demonstrates that lower NIHSS-time scores are strongly associated with favorable neurological outcomes. Patients with a NIHSS-time score less than 4093 had a significantly higher ratio of favorable neurological function after one month. The NIHSS-time score offers a practical tool for prognostic evaluation, emphasizing the urgency of EVT in acute ischemic stroke patients. However, further studies are needed to validate these findings and explore their generalizability.

The authors have declared no competing interest.

This study was registered retrospectively on China Medical University Hospital.

This work was supported by China Medical University Hospital, DMR-110-173. The funding source had no role in the design of the study, data collection, analysis, interpretation, or manuscript preparation. The authors or their institutions did not receive payment or services from any third party for any aspect of the submitted work.

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The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The study was approved by the Institutional Review Board (IRB) of China Medical University Hospital (CMUH110-REC3-189).

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