Internal Capsule Involvement Explains the Prognostic Impact of ASPECTS after Endovascular Thrombectomy for Large-Core...

Area of Science:

• Neurology
• Radiology
• Interventional Cardiology

Background:

• The Alberta Stroke Program Early CT Score (ASPECTS) is used to assess early ischemic changes in stroke patients.
• Its prognostic value for large-core ischemic stroke patients undergoing endovascular thrombectomy (EVT) requires further clarification.
• Specific ASPECTS regions may disproportionately affect functional outcomes post-EVT.

Purpose of the Study:

• To identify which individual ASPECTS subscores are associated with functional outcomes after EVT in large-core ischemic stroke.
• To determine if specific ASPECTS subscores mediate the association between total ASPECTS and outcomes.
• To investigate the prognostic significance of internal capsule (IC) involvement.

Main Methods:

• Retrospective analysis of 295 patients with large-core ischemic stroke (ASPECTS ≤ 5) who underwent EVT.
• Multivariate logistic regression to identify factors associated with functional outcomes (modified Rankin Scale - mRS).
• Mediation analysis to assess the role of ASPECTS subscores in the total ASPECTS-outcome relationship.

Main Results:

• Internal capsule (IC) involvement was the sole ASPECTS subscore significantly associated with worse functional outcomes (ordinal mRS shift, mRS ≥ 4, mRS ≥ 3).
• IC involvement explained 50.6% of the total ASPECTS effect on outcomes.
• Reversal of IC lesions on follow-up imaging correlated with a significantly lower risk of poor outcomes (OR 0.28).

Conclusions:

• Internal capsule (IC) involvement is an independent predictor of poor outcomes in patients with large-core ischemic stroke treated with EVT.
• IC involvement substantially mediates the prognostic impact of the total ASPECTS score.
• Targeting IC lesions or monitoring their resolution may improve outcome prediction in EVT patients.