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Updated: Feb 28, 2026
Optimized Management of Endovascular Treatment for Acute Ischemic Stroke
Published on: January 18, 2018
Endovascular Therapy Demonstrates Benefit over Intravenous Recombinant Tissue Plasminogen Activator Based on
Liqiong Fan1, Sharon D Yeatts1, Lydia D Foster1
1Department of Public Health Sciences, Medical University of South Carolina, Charleston, SC, and Departments of, OH, USA.
Background And Purpose:
The Interventional Management of Stroke (IMS) III trial was a randomized controlled trial designed to compare the effect of endovascular therapy after intravenous recombinant tissue plasminogen activator (i.v. rt-PA) as compared to i.v. rt-PA alone. The primary outcome was modified Rankin Scale at 90 days. Secondary outcomes included National Institutes of Health Stroke Scale (NIHSS), which was assessed repeatedly through 90 days. The objective of this analysis is to evaluate the treatment effect of endovascular therapy over time on NIHSS.
Methods:
656 subjects were enrolled in the IMS III trial, including 434 subjects randomized to endovascular therapy and 222 to i.v. rt-PA only. NIHSS scores evaluated at 40 min, 24 h, Day 5, and Day 90 were included in the analysis. A covariance structure model was used to investigate the treatment effect on NIHSS over time, adjusting for relevant covariates including baseline stroke severity. Model assumptions were valid.
Results:
Based on the covariance structure model, after adjusting for relevant baseline covariates, a significant time-by-treatment interaction effect (p = 0.0137) was observed. Only NIHSS at Day 90 showed a significant treatment effect (p = 0.0473), with subjects in the endovascular arm having a lower NIHSS (less neurologic deficit) compared to the i.v. rt-PA arm.
Conclusions:
The IMS III trial demonstrated an endovascular treatment effect based on the secondary outcome of NIHSS. However, the magnitude of this treatment effect varied by the time of assessment. It was only at Day 90 that the endovascular arm had a significantly lower NIHSS compared to that in the i.v. rt-PA arm.
