ABSTRACT NUMBER: ESOC2026A1730 TIME-DEPENDENT EFFICACY OF THROMBOLYSIS BEFORE THROMBECTOMY: RESULTS FROM INTERNATIONAL REGISTRY OF STROKE CARE QUALITY (RES-Q)

Abstract Background and aims Intravenous thrombolysis (IVT) before endovascular thrombectomy (EVT) may provide time-dependent benefit in acute ischaemic stroke. We assessed associations of IVT+EVT versus EVT alone across onset-to-needle time intervals. Methods We analysed prospectively collected RES-Q data from 3,132 adults with anterior-circulation large vessel occlusion treated with IVT+EVT or EVT alone within 270 minutes of onset. After excluding 123 patients with missing or erroneous onset-to-needle data, 3,009 were analysed. Groups were balanced using inverse probability of treatment weighting (IPTW). Onset-to-needle time was categorised as ≤100, 101–150, 151–255, and >255 minutes. IPTW-adjusted ordinal logistic regression assessed discharge modified Rankin Scale (mRS) shift; logistic regression assessed discharge survival and functional independence (mRS 0–2). Results Compared with EVT alone, IVT+EVT initiated ≤100 minutes was associated with improved mRS shift (common OR 1.99, 95% CI 1.49–2.63), survival (OR 1.81, 1.13–2.92), and mRS 0–2 (OR 1.76, 1.24–2.51). For 101–150 minutes, associations persisted for mRS shift (OR 1.58, 1.21–2.06) and mRS 0–2 (OR 1.64, 1.16–2.31), with borderline survival benefit (OR 1.55, 0.99–2.44). Beyond 150 minutes, IVT+EVT was not associated with improved mRS shift or survival; however, in the >255-minute window, IVT+EVT was associated with functional independence (OR 1.65, 95% CI 1.00–2.71). Conclusions The IVT showed the clearest added benefit when initiated early, with limited benefit beyond 150 minutes, supporting the rapid initiation of IVT when feasible. Conflict of interest All the authors declare nothing to disclose Table 1 - belongs to Results