ABSTRACT NUMBER: ESOC2026A2425 TIMING AS A KEY DETERMINANT OF INTRAVENOUS THROMBOLYSIS BRIDGING THERAPY BEFORE ENDOVASCULAR THROMBECTOMY – A MULTICENTER COHORT STUDY FROM THE EVATRISP COLLABORATION

Abstract Background and aims Current evidence supports intravenous thrombolysis (IVT) as bridging therapy before endovascular thrombectomy (EVT). However, as the efficacy and safety of IVT decrease with increasing time from symptom onset, we aimed to assess the time-dependent impact of bridging therapy. Methods This multicenter observational study from the EVA-TRISP collaboration included patients presenting within 4 hours of symptom onset. We evaluated the efficacy and safety of bridging therapy by comparing patients treated with IVT-EVT with those undergoing direct-EVT across predefined time intervals. A prespecified subgroup analysis was performed in octogenarian patients. Results Among 10,882 patients (age 72.1±13.8 years; 52.1% men), 5,854 (53.8%) received bridging-IVT. Compared with direct-EVT, IVT-EVT was associated with higher rates of favorable functional outcome (48.3% vs 36.2%, p<0.001), lower mortality (16.6% vs 25.3%, p<0.001), and higher successful recanalization rates (78% vs 76%, p=0.02). In multivariable analyses, IVT-EVT independently predicted favorable outcome (aOR 1.53, p<0.001), with benefit confined to the first 3 hours after symptom onset. Bridging therapy was also associated with lower mortality rates in patients presenting within 2 hours, and with first-pass effect only among patients presenting within one hour (aOR 1.91, p<0.001). Among octogenarian patients (n=3681), IVT-EVT was superior to the Direct-EVT only within the first two-hour-stratified subgroups. Additionally, IVT-EVT was associated with higher odds of symptomatic intracerebral hemorrhage in the fourth hour (aOR 1.90; p=0.03). Conclusions In this large real-world cohort, bridging IVT was associated with improved functional outcomes, with benefits dependent on treatment timing. These findings reinforce the time-sensitive nature of bridging therapy, particularly among octogenarians. Conflict of interest All authors have no relevant disclosures.