ABSTRACT NUMBER: ESOC2026A1112 THROMBECTOMY PASS NUMBER MODIFIES THE ASSOCIATION BETWEEN INTRA-ARTERIAL ALTEPLASE AND OUTCOMES AFTER SUCCESSFUL REPERFUSION

Abstract Background and aims Despite successful angiographic reperfusion, functional recovery varies. Thrombectomy pass number may reflect procedural complexity and modify the effect of adjunctive intra-arterial alteplase. Methods We conducted a post-hoc exploratory analysis of the PRAEL trial (NCT05856851). Patients were stratified by thrombectomy pass number (<2 vs ≥2) and treatment assignment (intra-arterial alteplase vs standard treatment). The primary outcome was the modified Rankin Scale (mRS) score 0–1 at 90 days, and the safety outcome concluded symptomatic intracranial hemorrhage (sICH) within 36 hours. Results Of the 324 patients, 164 were assigned to intra-arterial alteplase group and 160 to the standard treatment group. Among patients receiving standard medical treatment, mRS 0–1 at 90 days occurred in 36.1% of those with fewer than 2 thrombectomy passes compared with 21.0% of those with 2 or more passes (adjusted risk ratio [RR], 1.73 [95% CI, 0.98–3.04]), while sICH within 36 hours was less frequent in the <2-pass group (1.0% vs 11.3%; adjusted RR, 0.08 [95% CI, 0.01–0.59]). In contrast, among patients treated with intra-arterial alteplase, rates of mRS 0–1 were similar between two groups (48.1% vs 41.5%; adjusted RR, 0.98 [95% CI, 0.61–1.59]), with sICH occurring in 1.2% and 7.3% of patients, respectively. Conclusions Thrombectomy pass number was associated with outcomes and safety under standard medical treatment but not with intra-arterial alteplase. Pass number may therefore help identify patients more likely to benefit from adjunctive intra-arterial thrombolysis. Conflict of interest Jinyuan Wang: nothing to disclose, Yaxuan Pi: nothing to disclose, Yanting Chen: nothing to disclose, Xiaoming Rong: nothing to disclose, Mengqi Liu: nothing to disclose, Qianqing Li: nothing to disclose, Yongteng Xu: nothing to disclose, Songhua Xiao: nothing to disclose, Xinguang Yang: nothing to disclose, Yamei Tang: nothing to disclose.