ABSTRACT NUMBER: ESOC2026A1414 ENDOVASCULAR THROMBECTOMY WITH OR WITHOUT INTRAVENOUS THROMBOLYSIS ACROSS ISCHEMIC INJURY AND CLINICAL SEVERITY: AN INDIVIDUAL PARTICIPANT DATA META-ANALYSIS OF SIX RANDOMIZED TRIALS

Abstract Background and aims Whether prior intravenous thrombolysis (IVT) modifies outcomes after endovascular thrombectomy (EVT) remains uncertain. We conducted a one-stage individual participant data meta-analysis of six randomized trials from the Improving Reperfusion Strategies in Ischemic Stroke (IRIS) collaboration to evaluate EVT with versus without IVT across imaging–clinical profiles. Methods Patients with anterior-circulation large-vessel occlusion were randomized to EVT alone or IVT+EVT. Profiles were defined by ASPECTS, NIHSS, and a prespecified simple imaging–clinical equation (ASPECTS + 0.2×NIHSS) reflecting imaging–clinical discordance. The primary outcome was 90-day mRS shift analyzed using mixed-effects ordinal logistic regression with a trial random intercept, adjusted for age, atrial fibrillation, occlusion site, and onset-to-randomization time. Interaction tests evaluated effect heterogeneity across strata. Results Of 2312 randomized patients, 2270 were analyzed (1129 EVT alone). Across ASPECTS strata, EVT alone showed no clear overall advantage, with no significant interaction across ASPECTS or ASPECTS–NIHSS groups. Restricted cubic splines supported two knots (13 and 15) for the equation, defining three strata. Treatment-effect heterogeneity was observed across equation strata (P-interaction=0.04): 0–13 OR 0.99 (95% CI 0.83–1.17), 13–15 OR 1.40 (1.01–1.96; p=0.04), and 15–18 OR 0.81 (0.31–2.11). Conclusions Overall, functional outcomes did not differ consistently between EVT alone and IVT+EVT across ischemic injury or clinical severity profiles. However, patients with intermediate imaging–clinical discordance (equation 13–15) showed a trend favoring EVT alone, suggesting that a simple profile-based approach may help inform rapid, individualized bridging decisions when only limited information is available. Conflict of interest nothing to disclose Table 1 - belongs to Results Table 2 - belongs to Conclusions