Abstract TMP87: Thrombus Age in Ischemic Stroke With Atrial Fibrillation

Abstract

Background and purpose: Because the biochemical composition of thrombus changes after formation over time, thrombus maturation in the left atrium may affect clot compositions in ischemic stroke with atrial fibrillation (AF). We aimed to investigate the association of the age of retrieved thrombi with clinical features and outcomes after MT for ischemic stroke with AF. Methods: We retrospectively reviewed consecutive patients with ischemic stroke with known AF or AF diagnosed after stroke onset who underwent MT and whose retrieved thrombi were pathologically analyzed. Thrombi were classified as fresh (<1 day) and older (1-5 days) based on the areas (≤20 % or >20 %) of lytic features of granulocytes in the section. Components of thrombi were quantified using immunostaining. Outcomes included first pass effect (FPE, extended Thrombolysis in Cerebral Infarction [eTICI] 2c/3 after first pass) and favorable outcome (3-month modified Rankin Scale score of 0 to 2 or equal to premorbid mRS score). Results: Of 168 patients, 62 patients (37%) had older thrombi. The presence of older thrombi was independently associated with the higher CHADS 2 score (adjusted OR [aOR], 1.46; 95% confidence interval [CI], 1.07-1.99). Older thrombi had the higher proportion of fibrin, platelets, von Willebrand factor, and neutrophil extracellular traps than fresh thrombi. FPE was less frequently achieved in patients with older thrombi than those with fresh thrombi (21% versus 43%; aOR, 0.36; 95% CI, 0.17-0.77). Favorable outcomes were fewer in patients with older thrombi than those with fresh thrombi (40% versus 73%; aOR, 0.37; 95% CI, 0.16-0.85). Conclusions: In patients with ischemic stroke with AF, older thrombi was associated with cardiovascular risk factors and included abundant amounts of components associated with the thrombectomy resistance. Patients with older thrombi had poorer functional outcomes presumably due to concomitant risk factors and worse revascularization outcomes.