Abstract WP028: Efficacy and Safety of Tenecteplase versus Alteplase Across Different Treatment Time Windows: A Monocentric One-Year Stroke Center Experience

Introduction: Tenecteplase (TNK) offers pharmacological advantages over alteplase (rt-PA) and is increasingly adopted as the primary thrombolytic agent for intravenous thrombolysis (IVT) in acute ischemic stroke (AIS). Our tertiary-care stroke center transitioned from rt-PA to TNK in June 2024, enabling real-world evaluation across conventional and extended treatment time windows. This study aimed to compare efficacy and safety outcomes one year before and after transition. Methods: We retrospectively analyzed our institutional stroke registry, including all AIS patients treated with IVT one year before (rt-PA: June 2023–May 2024) and one year after transition (TNK: June 2024–May 2025). IVT was analyzed in both the conventional (≤4.5h) and extended (>4.5h) treatment windows, as well as in off-label scenarios such as treatment under oral anticoagulation (OAC). Primary endpoints included treatment metrics (door-to-needle DTN, imaging-to-needle, door-to-groin, and door-to-recanalization times). Safety endpoints comprised any intracranial hemorrhage (ICH) and symptomatic ICH (sICH; SITS-MOST). Results: A total of 591 patients received IVT (rt-PA: n=278; TNK: n=313), 69% within ≤4.5h and 31% beyond 4.5h. DTN times were significantly shorter with TNK compared to rt-PA (31 min IQR 22–48 vs. 35 min 26–54; p=0.002), driven by reduced imaging-to-needle times (12 min 7–25 vs. 16 min 9–29; p<0.001). Safety outcomes showed no significant differences between TNK and rt-PA – neither overall (any ICH: 8% vs. 7%, p=0.12; sICH SITS-MOST: 1% vs. 1%, p=0.75) nor across different treatment windows and off-label scenarios such as IVT under OAC. Conclusion: In this large, real-world, one-year cohort comparison, transitioning from rt-PA to TNK improved treatment efficiency while maintaining comparable safety. TNK proved feasible and safe not only within the conventional window but also beyond 4.5 hours and in selected off-label scenarios, supporting its role as a first-line thrombolytic agent in routine stroke care.