Abstract 129: Endovascular Therapy Demonstrates Benefit over IV-tPA based on 90-day NIHSS: A Longitudinal, Secondary Analysis of the IMS III Trial
Introduction: The IMS III trial was a randomized controlled trial designed to compare the add-on effect of endovascular therapy after IV-tPA. The primary outcome was mRS at 90 days. Secondary outcomes included NIHSS, which was evaluated repeatedly through 90 days.
Objective: 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 IV-tPA only. NIHSS evaluated at 40 min, 24 hours, Day 5 and Day 90 were included in the analysis. A mixed effects model was used to investigate the treatment effect on NIHSS over time, adjusting for relevant covariates including baseline stroke severity (NIHSS ≤19 vs ≥20). Model assumptions were held.
Result: After adjusting for age, time from symptom onset to initiation of IV tPA, and baseline stroke severity, 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 lower NIHSS compared to the IV- tPA arm (mean 7 vs 8).
Conclusion: 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 time of assessment. It was only at Day 90 that the endovascular arm had a significantly lower NIHSS compared to those in the IV- tPA arm.
Author Disclosures: L. Fan: None. S.D. Yeatts: Other Research Support; Significant; NINDS-funding, unblinded statistician in IMS III. Consultant/Advisory Board; Significant; Genentech,member of PRISMS Trial Steering Committee. L.D. Foster: Other Research Support; Significant; NINDS, unblinded statistician on the IMS3 Trial. P. Khatri: Research Grant; Modest; Dr. Khatri’s Dept of Neurology receives support for her role DSMB member from Biogen, Inc.. Research Grant; Significant; Dr. Khatri’s Dept of Neurology receives support for her roles as: (1) Lead PI of the PRISMS trial from Genentech, Inc and (2) Neurology PI of the THERAPY trial from Penumbra, Inc. T. Tomsick: Research Grant; Significant; IMS III Trial, CO-PI. J.P. Broderick: Other Research Support; Modest; Genetech, Study medication for IMS III Trial. Other Research Support; Significant; Genetech, research suport for PRISMS Study. Y.Y. Palesch: None.
- © 2015 by American Heart Association, Inc.