Perfusion mismatch profiles were not associated with functional outcomes and did not modify the effect of EVT in acute MeVO stroke, suggesting that perfusion imaging based on currently used thresholds and cutoffs did not identify patients likely to benefit from thrombectomy.
Key Findings
Results
Perfusion mismatch volume was not associated with 90-day ordinal modified Rankin Scale score in acute MeVO stroke.
Adjusted odds ratio (AOR) for ordinal 90-day mRS was 1.03 (95% CI, 0.99–1.07) per 10-mL increase in perfusion mismatch volume.
Median (IQR) perfusion mismatch volume was 37.2 (22.1–57.2) mL across the 309 included patients.
Analysis included 309 of 530 enrolled ESCAPE-MeVO patients who had interpretable baseline perfusion imaging (EVT: n=146; usual care: n=163).
Results were consistent across secondary outcomes and subgroups.
Results
Perfusion mismatch ratio was not associated with 90-day ordinal modified Rankin Scale score in acute MeVO stroke.
AOR for ordinal 90-day mRS was 1.03 (95% CI, 0.97–1.09) per 1-unit increase in perfusion mismatch ratio.
Median (IQR) mismatch ratio was 6.1 (2.8–10.0) in the included cohort.
Perfusion mismatch ratio was defined as the ratio between the critically hypoperfused area and the ischemic core.
Results were consistent across secondary outcomes including 24-hour follow-up infarct volume and 90-day mRS 0–1 and 0–2.
Results
Perfusion mismatch volume and ratio did not modify the effect of EVT on functional outcomes in MeVO stroke.
No statistically significant interaction was found between perfusion mismatch volume or ratio and EVT effect on ordinal 90-day mRS.
The analysis was a post hoc exploratory analysis of the ESCAPE-MeVO randomized clinical trial.
ESCAPE-MeVO enrolled patients within 12 hours from last known well with evidence of salvageable brain tissue between April 2022 and June 2024.
EVT was compared to usual care alone; primary outcome was 90-day ordinal mRS score.
Methods
The ESCAPE-MeVO perfusion imaging subsample was broadly representative, with 58.3% of enrolled patients having interpretable baseline perfusion imaging.
309 of 530 enrolled patients had available baseline perfusion imaging and were included.
Patient median (IQR) age was 73 (63–82) years, and 141 (45.6%) were women.
Volume thresholds were defined by site-specific postprocessing software, reflecting real-world heterogeneity in perfusion analysis.
The trial was multicenter, conducted in North America, Europe, and the United Kingdom.
Discussion
Perfusion imaging profiles based on currently used thresholds and cutoffs did not identify patients likely to benefit from EVT in the ESCAPE-MeVO trial.
This finding is consistent across both the primary outcome (ordinal 90-day mRS) and secondary outcomes.
The study was an exploratory post hoc analysis, limiting causal inference.
The results extend the primary ESCAPE-MeVO trial finding of no overall EVT benefit to perfusion-selected subgroups.
The authors note this suggests current perfusion mismatch thresholds may not be adequate for patient selection in MeVO stroke.
What This Means
This research examined whether brain perfusion imaging — which measures areas of the brain at risk but not yet permanently damaged — could identify which stroke patients with blockages in medium-sized blood vessels (medium vessel occlusions, or MeVO) might benefit from a clot-removal procedure called endovascular thrombectomy (EVT). The study analyzed data from 309 patients in the ESCAPE-MeVO clinical trial, comparing EVT plus standard medical care to standard care alone. Researchers looked at two perfusion imaging measures: the volume of salvageable brain tissue and the ratio of at-risk tissue to already-damaged tissue.
The study found that neither measure of perfusion mismatch was associated with better or worse functional outcomes at 90 days, and neither measure changed whether EVT helped or harmed patients compared to standard care alone. This was true across multiple ways of measuring outcomes, including disability scores and final infarct volume. In other words, patients with more salvageable brain tissue on imaging did not appear to do better with EVT than those with less salvageable tissue.
This research suggests that the perfusion imaging tools and thresholds currently used in clinical practice are not able to pick out MeVO stroke patients who would benefit from the clot-removal procedure, unlike what has been shown for large vessel occlusion strokes. This has important implications for how doctors select MeVO stroke patients for treatment, and highlights the need for either better imaging criteria or different patient selection strategies before perfusion imaging can guide EVT decisions in this stroke subtype.
Pensato U, Jindal G, Diprose W, Ganesh A, Charatpangoon P, MacDonald E, et al.. (2026). Thrombectomy for Acute Stroke Due to Medium Vessel Occlusion Across Perfusion Mismatch Profiles: A Post Hoc Analysis of the ESCAPE-MeVO Trial.. JAMA network open. https://doi.org/10.1001/jamanetworkopen.2026.38823