Prognostic Value of Collateral Assessment in Acute Large-Core Infarction after Endovascular Thrombectomy

Functional outcomes after endovascular thrombectomy (EVT) for acute large-core infarction are highly heterogeneous. While collateral status is a key imaging biomarker, its prognostic role in this specific population is not well established. We aimed to perform a head-to-head comparison of CTA-based and DSA-based collateral assessment to determine their prognostic value.

This post hoc analysis of a prospective multicenter registry included patients with acute anterior-circulation large-core infarction (ASPECTS 0-5) who underwent EVT between November 2021 and February 2023. Collateral status was assessed using the CTA-based Tan score and the DSA-based ASITN/SIR grade. The primary outcome was a favorable functional outcome, defined as a modified Rankin Scale (mRS) score of 0 to 3 at 90 days.

Of 750 eligible patients in the registry, 287 with acute large-core infarction and complete imaging were included. Both the Tan score (aORs for higher grades, 3.06 to 6.45; P < 0.01) and ASITN/SIR grade (aORs for higher grades, 3.28 to 4.01; P < 0.01) independently predicted functional outcome at 90 days. The Tan score (AUC 0.703, 95% CI 0.646 to 0.760) and ASITN/SIR grade (AUC 0.684, 95% CI 0.626 to 0.743) established comparable prognostic accuracy (P = 0.611). An exploratory combining both collateral scoring systems showed superior predictive performance to either system alone (AUC 0.747; 95% CI 0.691 to 0.803; P < 0.01).

In acute large-core infarction, CTA-based collateral assessment demonstrates prognostic value comparable to the DSA-based gold standard.