ABSTRACT NUMBER: ESOC2026A1426 RTPA BIOAVAILABILITY AND THROMBUS COMPOSITION IN ANTERIOR CIRCULATION ATHEROMATOUS TANDEM OCCLUSIONS WITH OR WITHOUT INTRAVENOUS THROMBOLYSIS: INSIGHT FROM THE ETIS AND COMPOCLOT STUDIES

Abstract Background Tandem occlusions are singular entity, mostly of atheromatous origin. Despite clinical evidence suggesting its benefit in this setting, the place of intravenous thrombolysis (IVT) among the therapeutic strategy remains questioned. In particular, whether the IVT agent reaches the intracranial occlusion is not known. Objectives Our objective was to determine the bioavailability of the recombinant tissue Plasminogen Activator (rtPA) and the thrombus composition according the IVT status. Methods We investigated the rtPA concentration and thrombus composition in consecutive thrombi from patients with acute ischemic stroke due to atheromatous anterior circulation tandem lesion, enrolled in the multicenter research cohort CompoClot. Results During the study period, 84 patients’ thrombi were analyzed: 44 received prior IVT and 40 did not. The thrombi tPA concentration was significantly higher in the IVT group in comparison with patients without prior IVT (median 0.283 vs 0.067; p=0.002), with an adjusted standardized difference of 0.70 (95%CI, 0.26 to 1.14). The dosage of biomarkers of thrombus composition were similar between groups. In the IVT-group, tPA concentration was negatively correlated with delay between IVT and recanalization (r=-0.34, p=0.030). Thrombi from both groups similarly responded to in vitro thrombolysis. Conclusion Our study indicated that the thrombolytic agent was detected in the intracranial thrombi of patients with acute atheromatous tandem occlusions, reinforcing the interest of IVT in this setting. Conflict of interest Nothing to disclose