Percent Insular Ribbon Infarction for Predicting Infarct Growth Rate and 90-Day Outcomes in Large-Vessel Occlusive...

Area of Science:

• Neurology
• Radiology
• Stroke Medicine

Background:

• Understanding infarct progression is crucial for optimizing stroke treatment timing.
• Delayed endovascular thrombectomy (EVT) may benefit select patients with slowly progressing strokes.
• Identifying reliable imaging biomarkers for infarct growth is essential.

Purpose of the Study:

• To evaluate the association between percent insular ribbon infarction (PIRI) and infarct growth rate (IGR) in large-vessel occlusive stroke.
• To assess the relationship between PIRI and 90-day functional outcomes (modified Rankin Scale [mRS]).
• To determine if PIRI can predict which patients might benefit from delayed EVT.

Main Methods:

• Retrospective analysis of 31 patients with anterior circulation large-vessel occlusion from a prior clinical trial.
• Independent neuroradiologist scoring of PIRI on baseline MRI using a 0-4 scale, categorized as mild, moderate, or severe.
• Measurement of infarct volumes and infarct growth rates (IGR) from serial MRI scans; assessment of 90-day mRS outcomes.

Main Results:

• Strong interrater agreement for PIRI scoring (κ = 0.89).
• Significant associations found between PIRI severity and IGR from onset to presentation (p < .001) and from presentation to 48 hours (p = .005).
• Severe PIRI was strongly linked to larger 90-day infarct volumes (p = .01) and worse functional outcomes (90-day mRS ≥ 2, p = .001).

Conclusions:

• PIRI is an independent predictor of infarct growth rate and 90-day functional outcomes in large-vessel occlusive stroke.
• PIRI severity effectively differentiates patients with rapid versus slow infarct progression.
• PIRI may serve as a valuable imaging biomarker to identify candidates for late-window EVT.