ABSTRACT NUMBER: ESOC2026A2402 HIGHER PLATELETS-LYMPHOCYTE AGGREGATES OF INTRACRANIAL THROMBUS PREDICT CLINICAL SEVERE OUTCOMES AFTER SUCCESSFUL MECHANICAL THROMBECTOMY

Abstract Background and aims Our objective is to identify thrombus composition and other factors associated with severe clinical outcomes after successful mechanical thrombectomy (SMT). Methods Tandem occlusions were excluded. SMT cases with final mTICI > 2b were included . Each thrombus was analyzed by Flow Cytometry for main leukocyte composition and leukocyte-platelet subpopulations: platelets-Lymphocytes, platelets-monocytes and platelets-granulocytes aggregates. Thrombus analysis, baseline variables, antithrombotic treatment, etiology, neuroimaging and reperfusion treatment were analyzed to evaluate associations with severe outcomes defined as mRs 4, 5 or 6 at 3 months. Results Almost 50% of patients developed severe outcomes (22/45). Higher NIHSS score (20 vs 13, p=0.07) and passes (2 vs 1 p=0.09), hyperglycemia (116 mg vs 111mg p=0.018), slower procedures (46 vs 38 minutes of groin-to-recanalization p 0.026), worse ASPECTS (8 vs 10 p=0.014), cardioembolic etiology [ 19 (86%) vs 12 (57%) ], no-chronic antiplatelet treatment [ 4(18%) vs10 (47%) p =0.39], higher monocyte-to-lymphocyte ratio [ 4% ( 2-8) vs. 2% (1-5); p=0.039] and higher platelets-lymphocytes aggregates [34% (18- 61) vs 21% (9-34); p= 0.046 ] in thrombus analysis were associated with severe outcomes at 3 months. In the logistic regression analysis adjusted by age, intravenous fibrinolysis and significative features from univariate analysis, the only independent predictor of severe outcomes was the proportion of platelets-lymphocytes aggregates in intracranial thrombus (aOR 1.062, 95% CI 1.009- 1.119). Conclusions Rich platelets-lymphocytes thrombus is an independent predictor of severe outcomes at 3 months from stroke and a potential therapeutic target to improve the benefits of succesfull endovascular treatments. Conflict of interest nothing to disclose