Related Experiment Video
Updated: Oct 13, 2025
Methods for Acute and Subacute Murine Hindlimb Ischemia
Published on: June 21, 2016
Does variability in automated perfusion software outputs for acute ischemic stroke matter? Reanalysis of EXTEND
Andrew Bivard1, Leonid Churilov1, Henry Ma2
1Department of Medicine and Neurology, Melbourne Brain Centre at the Royal Melbourne Hospital, University of Melbourne, Parkville, VIC, Australia.
Aims:
We reprocessed the Extending the time for Thrombolysis in Emergency Neurological Deficits (EXTEND) perfusion imaging with a different automated software with the aim of comparing mismatch eligibility and outcomes.
Methods:
EXTEND baseline perfusion imaging data were reprocessed using autoMIStar software to identify patients who were eligible based on the same target mismatch criteria as per the original trial.
Results:
From the 225 patients fulfilling RAPID-based mismatch criteria randomized in the EXTEND study, 196 (87%) patients met the revised mismatch criteria. Most common reasons for not meeting revised criteria were core >70 ml (n = 9), and no perfusion lesion/lack of penumbral tissue (n = 20). The revised perfusion lesion volumes were significantly smaller compared to the original RAPID volumes (median 68 ml IQR 34-102 ml vs. 42 ml 16-92 ml, p = 0.036). Of the patients who met the revised mismatch criteria, 40% receiving alteplase had modified Rankin Scale (mRS) 0-1 at 3-month compared to 28% with placebo (Adjusted Odds Ratio (OR) = 2.23, CI 1.08-4.58, p = 0.028). In contrast, in the original mismatch cohort, 35% receiving alteplase had mRS 0-1 at 3-month compared to 30% with placebo (adjusted OR = 1.88, p = 0.056).
Conclusions:
These data reinforce the benefit of alteplase in the later time window, and suggest that differences in automated perfusion imaging software outputs may be clinically relevant.
