Persistent Target Mismatch Profile >24 Hours After Stroke Onset in DEFUSE 3

Area of Science:

• Neurology
• Radiology
• Interventional Cardiology

Background:

• Endovascular thrombectomy is effective up to 24 hours post-stroke in select patients.
• Perfusion imaging identifies patients who may benefit from thrombectomy.

Purpose of the Study:

• To investigate the existence and predictors of a persistent favorable perfusion profile beyond 24 hours after stroke onset.
• To determine if a lower baseline hypoperfusion intensity ratio predicts favorable collaterals and persistent mismatch.

Main Methods:

• Analysis of control arm patients from the DEFUSE 3 trial.
• Comparison of diffusion-weighted imaging and perfusion MRI variables between persistent and non-persistent mismatch groups.
• Assessment of infarct growth and clinical outcomes at 90 days.

Main Results:

• 18% of control patients exhibited a persistent favorable perfusion profile >38 hours from last known well.
• Persistent mismatch patients had similar baseline infarct volumes but significantly less infarct growth (15 vs. 59 mL).
• A lower baseline hypoperfusion intensity ratio (0.2 vs. 0.4) predicted persistent mismatch.

Conclusions:

• A significant subset of stroke patients in the extended time window may have a persistent perfusion mismatch.
• Favorable hypoperfusion intensity ratio at presentation is a key predictor.
• These patients experience delayed infarct expansion and poor clinical outcomes without reperfusion, warranting further clinical trials.