ABSTRACT NUMBER: ESOC2026A1191 LONGITUDINAL CHANGES IN SERUM ENDOTHELIN-1 AND INTERLEUKIN-6 FOLLOWING ACUTE ISCHEMIC STROKE AND REVASCULARIZATION THERAPIES

Background and aims: Post-reperfusion complications remain common after ischemic stroke. Biomarkers may clarify mech- anisms and identify high-risk patients. We evaluated serum Endothelin-1(Et-1) and Interleukin-6 (IL6), comparing patients by revascularization therapy. Methods: We enrolled imaging-confirmed ischemic stroke patients (18-80 years, onset <24h, NIHSS>1, pre-stroke mRS<2). Those with prior neurological disease, immunosuppression, pregnancy, or severe renal failure were excluded. Twelve healthy controls were considered. Et-1 and IL6 were determined with Ella on samples collected within 24h (T0), 3-5d (T1) and 7±2d (T2). Results: Ninety-eight patients were enrolled (59M, median age 68.4y[IQR58.6-74.1]). At onset, NIHSS was 1-4 in 58.2%, 5-15 in 32.7%, >16 in 9.1%; 44.9% underwent no procedures (NRP), 33.7% thrombolysis (IVT), 11.2% endovascular thrombectomy (EVT), 10.2% IVT+EVT. Et-1 was higher at T0 vs. controls, T1 and T2 (Fig1A); IL6 at T0 vs. controls (Fig. 1B). Between revascularization groups, Et-1 was higher in EVT vs. NRP at T0 and T1 (Fig1C), while IL6 only at T0 (Fig1D). Higher Et-1 and IL6 at T0 were independently associated with lower-odds of good outcome (mRS 0-2) at 90d (Et- 1:aOR 0.43, 95%CI 0.25-0.74; IL6:aOR 0.95, 95%CI 0.90-1.00). Only Et-1 was independently associated with lower odds of full recovery to pre-stroke functional status (aOR 0.69, 95%CI 0.51-0.93). Conclusions: Et-1 and IL6 peak 24h after stroke, being higher in EVT, with prognostic relevance diverging: IL6 is associated to worse outcome, whereas Et-1 may reflect mechanisms that hinder full neurological recovery. Funding. Ricerca Corrente (IRCCS-Mondino)