ABSTRACT NUMBER: ESOC2026A1019 CEREBRAL COLLATERAL STATUS AND OUTCOMES WITH ADJUNCTIVE INTRA-ARTERIAL ALTEPLASE AFTER SUCCESSFUL ENDOVASCULAR REPERFUSION FOR ACUTE LARGE VESSEL OCCLUSION STROKE: SUBGROUP ANALYSIS OF THE PEARL TRIAL

Abstract Background and aims This study aimed to evaluate whether the efficacy of adjunctive intra-arterial alteplase (IAA) after successful endovascular reperfusion in patients with acute ischemic stroke is modified by cerebral collateral status. Methods This was a post hoc analysis of the PEARL randomized clinical trial (NCT05856851). Among 324 randomized patients, 235 who underwent baseline computed tomographic angiography with collateral assessment using the Tan score were included, with scores of 0–1 indicating poor and 2–3 indicating good collateral circulation. The primary outcome was a modified Rankin Scale (mRS) score of 0-1 at 90 days. Safety outcomes included symptomatic intracranial hemorrhage and any intracranial hemorrhage within 36 hours, and all-cause mortality within 90 days. Results Of the 235 included patients, 152 had good collateral circulation, including 72 assigned to the IAA group (47.4%) and 80 to the standard treatment group (52.6%). Among patients with good collaterals, the proportion achieving mRS 0–1 at 90 days was higher in the IAA group than in the control group (52.8% vs 38.0%; adjusted risk ratio [RR], 1.45 [95% CI, 1.05–2.01]; P=0.0247). In patients with poor collateral circulation, no significant difference in functional outcome was observed between the two groups (52.8% vs 38.0%; adjusted RR, 1.50 [95% CI, 0.67–3.38]; P=0.32). No significant interaction between collateral status and treatment effect was observed (P for interaction = 0.95). Conclusions Adjunctive intra-arterial alteplase following endovascular reperfusion was associated with favorable functional outcomes in patients with good collateral circulation, highlighting the potential clinical relevance of collateral status in this setting. Conflict of interest Xiaoming Rong, Xuejing Lin, Zhenhong Deng, Yanting Chen, Jinyuan Wang, Mengqi Liu, Yaxuan Pi, Yongteng Xu, Songhua Xiao, Xinguang Yang and Yamei Tang: nothing to disclose.