ABSTRACT NUMBER: ESOC2026A894 EFFICIENCY AND SAFETY OF TENECTEPLASE VERSUS ALTEPLASE ACROSS DIFFERENT TREATMENT TIME WINDOWS: A MONOCENTRIC ONE-YEAR STROKE CENTER EXPERIENCE

Abstract Background and aims Tenecteplase (TNK) offers pharmacological advantages over alteplase (rt-PA) and is increasingly used for intravenous thrombolysis (IVT) in acute ischemic stroke (AIS). Our stroke center switched from rt-PA to TNK in June 2024, enabling a real-world comparison of treatment efficiency and safety across conventional, extended treatment, and other off-label scenarios. Methods We retrospectively analyzed our stroke registry including all AIS patients treated with IVT 12 months before (rt-PA: June 2023–May 2024) and after (TNK: June 2024–May 2025) the transition. IVT was administered within ≤4.5 hours, >4.5 hours and in selected off-label settings, including under oral anticoagulation. Primary endpoints were in-hospital workflow times (door-to-needle [DTN], door-to-imaging [DTI], imaging-to-needle [ITN], door-to-groin, door-to-recanalization). Safety endpoints included any intracranial hemorrhage (ICH) and symptomatic ICH (sICH; SITS-MOST). Propensity score matching (PSM) and adjusted analyses were applied. Results Overall, 591 patients received IVT (rt-PA n=278; TNK n=313); 69% were treated within ≤4.5 hours and 31% beyond. TNK was associated with shorter DTN times compared with rt-PA (31 [IQR 22–48] vs. 35 min [26–54]; p=0.002), driven by reduced ITN times (12 [7–25] vs. 16 min [9–29]; p<0.001). Safety outcomes were comparable, confirmed by PSM and adjusted analyses with no significant differences in any ICH (8% vs. 7%; p=0.61) or sICH (3% vs. 1%; p=0.34) and no increase in hemorrhagic complications in aforementioned off-label scenarios. Conclusions Transitioning from rt-PA to TNK significantly improved in-hospital workflow efficiency while maintaining comparable safety in routine clinical practice, supporting TNK as a first-line thrombolytic agent. Conflict of interest Alexander Sekita: nothing to disclose; Kosmas Macha: nothing to disclose; Ludwig Singer: nothing to disclose; Stefan Schwab: nothing to disclose; Stefan T. Gerner: nothing to disclose;