Post-thrombolysis computed tomography angiography and perfusion features associated with an unfavorable early neurological response: a single-center retrospective study in a clinically selected anterior-circulation cohort

Abstract

Background Early neurological non-response or worsening after intravenous thrombolysis (IVT) for acute ischemic stroke (AIS) is associated with poor outcomes, but its post-treatment imaging correlates remain incompletely understood. This study evaluated computed tomography angiography (CTA) and computed tomography perfusion (CTP) features associated with an unfavorable early neurological response (UENR). Methods In this single-center retrospective study, consecutive patients with AIS who received IVT between 2020 and 2025 and underwent CTA and perfusion within 24 hours because of a lack of improvement or initially severe deficits were included. A UENR was defined as an improvement of no more than 1 point or any increase in the National Institutes of Health Stroke Scale (NIHSS) score at 24 hours. Patients with an improvement of at least 4 points or a 24-hour score of 0–1 comprised the favorable response (FR) group. Imaging variables included post-treatment vessel patency, collateral status assessed with the Tan score, and estimated ischemic core and total hypoperfusion volumes. Results Among 185 patients, 62 (33.5%) had an unfavorable response and 123 (66.5%) had a favorable response. The unfavorable-response group had a higher baseline NIHSS score (median 16 vs. 12; P<0.001) and a higher rate of poor 90-day functional outcome. Post-treatment imaging showed a lower vessel patency rate (24.2% vs. 78.9%; P<0.001), a higher prevalence of poor collateral status (66.1% vs. 17.1%; P<0.001), and a larger estimated ischemic core (median 28.5 vs. 6.1 mL; P<0.001) in the unfavorable-response group. In multivariable logistic regression, persistent occlusion [adjusted odds ratio (aOR), 7.85; 95% confidence interval (CI): 3.60–16.80], poor collateral status (aOR, 4.05; 95% CI: 1.85–8.60), and larger ischemic core volume per 10 mL increase (aOR, 1.82; 95% CI: 1.35–2.45) were independently associated with an unfavorable response (all P<0.001). Conclusions In this clinically selected cohort, a UENR was associated with persistent vessel occlusion, poor collateral status, and a larger estimated ischemic core on post-treatment imaging. These findings characterize the concurrent vascular and tissue state of patients with early non-response or worsening and should not be interpreted as baseline predictors.