Collateral status predicts functional outcome in early-treated large-core anterior circulation stroke

Area of Science:

• Neurology
• Radiology
• Vascular Medicine

Background:

• Endovascular therapy (EVT) for large-core acute ischemic stroke (AIS) shows variable outcomes.
• Collateral circulation's role in early large-core stroke is not fully understood.
• Collaterals may influence infarct progression and patient recovery.

Purpose of the Study:

• To assess the impact of collateral circulation on outcomes in patients with large-core AIS treated within 6 hours.
• To determine if baseline collateral status predicts functional recovery after reperfusion therapy.

Main Methods:

• Retrospective analysis of 54 patients with anterior-circulation large-vessel occlusion and large ischemic core.
• Collateral status assessed using the Tan scale on baseline computed tomography angiography (CTA).
• Primary outcome: 90-day modified Rankin Scale (mRS); secondary outcome: NIHSS at discharge.

Main Results:

• Patients with absent collaterals (Tan 0) had significantly worse 90-day outcomes (median mRS 4) compared to those with collaterals (Tan 1 or 2, median mRS 1-2).
• Each one-grade increase in collateral status was associated with lower odds of a worse 90-day mRS (adjusted OR 0.32).
• Discharge NIHSS also showed a similar gradient correlating with collateral status.

Conclusions:

• Simple CTA-based collateral assessment is a strong predictor of recovery in early-treated large-core AIS.
• Absent collaterals are linked to a poorer clinical trajectory.
• Incorporating collateral status into routine evaluation can enhance prognostic accuracy and guide treatment decisions.