Prognostic value of histopathological thrombus age in large vessel occlusion related stroke

Abstract

Introduction Acute mechanical thrombectomy is the preferred treatment for large vessel occlusion related stroke. Histopathological research on the obtained occlusive embolic thrombus may provide information regarding the etiology and pathology of the lesion to predict prognosis and propose possible future acute ischemic stroke therapy. Methods A total of 75 consecutive patients who presented to the Amphia Hospital with acute large vessel occlusion related stroke and underwent mechanical thrombectomy were included in the study. The obtained thrombus materials were subjected to standard histopathological examination. Based on histological criteria they were considered fresh (1 day old). Patients were followed for two years for documentation of all-cause mortality. Results Thrombi were classified as fresh in 40 patients (53%) and as older in 35 patients (47%). Univariate Cox regression analysis showed that thrombus age, National Institutes of Health Stroke Scale at hospital admission and patient age were associated with long-term mortality (p<0.1). Multivariable Cox hazards and Kaplan Meier analysis demonstrated that after extensive adjustment for clinical and procedural variables thrombus age persisted in being independently associated with higher long-term mortality (hazard ratio: 3.34; p=0.038), (log rank p=0.013). Conclusion In this study, older thromboemboli are responsible for almost half of acute large ischemic strokes. Moreover, the presence of an old thrombus is an independent predictor of mortality in acute large vessel occlusion related stroke. More research is warranted regarding future therapies based on thrombus composition.