Abstract A077: Clot Origin Modifies the Effect of IV Thrombolysis on Recanalization Time in Thrombectomy: A Registry Analysis

Background and Purpose: Bridging intravenous thrombolysis (IVT) for anterior circulation large vessel occlusion (acLVO) stroke may alter clot architecture and influence thrombectomy performance, but effects may differ by clot origin. We investigated the association between IVT and time-to-recanalization during thrombectomy by stroke etiology. Methods: We conducted a time-to-event analysis of consecutive patients with acLVO from our prospective thrombectomy registry who were treated at a tertiary stroke center in Germany between January 2017 and January 2023. We assessed the association between bridging IVT and groin-to-recanalization time by stroke etiology (cardioembolic vs non-cardioembolic) using multivariable stratified Cox regression analysis adjusted for demographic, cardiovascular and stroke-related characteristics. Results: Of 1702 patients screened, 798 (413 female [51.8%], median age 77 years [66-84, IQR]) underwent thrombectomy for acLVO and were included. Of these, 395 (49.5%) received IVT and 680 (85.2%) achieved successful reperfusion. In non-cardioembolic stroke, bridging IVT was associated with a 40% higher likelihood of achieving successful reperfusion at any time point during thrombectomy compared with direct thrombectomy (adjusted HR 1.40; 95%CI [1.08, 1.81]; p=0.01; Figure 1A). In contrast, among cardioembolic stroke patients, IVT was linked to a 43% lower likelihood of successful reperfusion when distal thrombus migration was detected on repeated imaging (adjusted HR 0.57; 95%CI [0.33, 0.96]; p=0.03; Figure 1B). Conclusions: Bridging IVT accelerated reperfusion during thrombectomy in non-cardioembolic acLVO but was associated with delayed reperfusion in cardioembolic stroke with distal thrombus migration. Clot origin may be an important determinant of response to IVT before thrombectomy.