- Design
- Post hoc analysis of a multicentre randomised trial
- Population
- 309 patients with medium vessel occlusion stroke and interpretable perfusion imaging
- Primary outcome
- 90-day ordinal modified Rankin Scale
- Effect
- No association with mismatch volume (AOR 1.03, 0.99 to 1.07) or ratio; no effect modification
ESCAPE-MeVO randomised patients with medium vessel occlusion stroke within 12 hours to thrombectomy plus usual care or usual care alone, and found no overall benefit. This post hoc analysis took the 309 of 530 patients with interpretable baseline perfusion imaging.
Neither perfusion mismatch volume (median 37 mL) nor mismatch ratio (median 6.1) was associated with 90-day modified Rankin score, and neither modified the effect of thrombectomy. Results held across secondary outcomes and subgroups.
The hope after neutral medium vessel trials was that a favourable perfusion profile might identify a group who do benefit. With current software thresholds, this analysis did not find one. It is exploratory and limited to patients with usable scans, but it argues against using perfusion maps to justify thrombectomy for medium vessel occlusion outside trials.
- Do not use a favourable perfusion mismatch alone to justify thrombectomy for medium vessel occlusion
- Keep thrombolysis decisions for these patients on standard criteria
- Enrol eligible patients in ongoing trials where available
- Remember the analysis covered only the 58% of patients with interpretable perfusion imaging
Why it matters
It closes off one hoped-for way of selecting medium vessel patients for thrombectomy.
Don't overread it
This is an exploratory post hoc analysis; a different imaging marker could still identify a benefiting group.
The statistics, in plain English
An adjusted odds ratio of 1.03 per 10 mL of mismatch, with an interval spanning 0.99 to 1.07, means no meaningful link between mismatch size and outcome.
Read the rest in the app
You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this finding is waiting in it.
Scan to keep reading on your phone. No account needed to start.
Tomorrow morning, before your first patient
One edition a day for neurology, written by the desk, every claim tied to its paper. Six minutes.
Get the app — free