Abstract 9: Bridging thrombolysis prior to thrombectomy does not modify the association between Direct-to-angiography vs Repeat Imaging approaches and functional outcomes after EVT in transferred patients

Introduction: For patients transferred for EVT considerations, direct-to-angio approach is shown to reduce time to procedure and improve clinical outcomes. We aimed to assess if IV thrombolytics status prior to transfer modifies the association between direct-to-angio approach and improved clinical outcomes in transferred patients who received EVT. Methods: In a secondary analysis of a retrospective cohort of transferred EVT patients from 6 centers across US and Europe, patients were stratified based on IV thrombolytic status. Association of direct-to-angio approach vs repeated imaging approach with functional outcomes was assessed among patients with and without IV thrombolytics using appropriate regression models adjusted for age, stroke severity, time to procedure, occlusion location, serum glucose and successful reperfusion status. Heterogeneity of association was evaluated using multiplicative interaction. Results: Of 1135 patients with documented IV thrombolysis status, 612 (54%) received IVT – with younger age (IVT - 68 (57-78)y, no IVT - 70 (60-79)y, p=0.032) and higher CT ASPECTS (IVT: 8 (7-10) vs no IVT: 8 (7-9), p=0.038), but similar NIHSS (IVT: 17 (13-21) vs no IVT: 17 (12-21), p=0.91). Estimates of association favored direct-to-angio approach among both no IVT (acOR: 2.06, 95% CI: 1.38 to 3.08, p-value<0.001) and IVT (acOR: 1.33, 95% CI: 0.95 to 1.86, p-value: 0.099), without significant heterogeneity (p-interaction: 0.17). Similar findings were also observed for functional independence (IVT - aOR: 1.64, 95% CI: 1.08 to 2.49, p-value: 0.021; no IVT: aOR: 2.12, 95% CI: 1.25 to 3.58, p-value: 0.005; p-interaction: 0.57) and independent ambulation (IVT: aOR: 1.45, 95% CI: 0.93 to 2.26, p-value: 0.097; No IVT: aOR: 2.92, 95% CI: 1.68 to 5.06, p-value<0.001; p-interaction: 0.10) – Table 1. Interpretation: From a retrospective cohort of transferred patients who received EVT, use of IV thrombolytics at baseline did not modify the association between DTA vs RI approach and functional outcomes at 90-day follow-up, suggesting the feasibility of DTA approach regardless of baseline IVT status.