ASSOCIATION BETWEEN HISTOLOGY OF THROMBI RETRIEVED DURING MECHANICAL THROMBECTOMY AND ATRIAL CARDIOMYOPATHY MARKERS IN ESUS PATIENTS

Background. Data that could be obtained thanks to histological analyses of the thrombi retrieved during mechanical thrombectomy is still controversial; therefore, these analyses have not yet been included in the diagnostic work up after an ischemic stroke. Embolic strokes of undetermined source (ESUS) are a subtype of ischemic stroke whose therapeutic approach has not yet been defined. According to recent literature, atrial cardiomyopathy (a complex of pathological changes affecting the atria) could be the trigger of an ESUS in those patients with no evidence of atrial fibrillation. Aim of the study is to demonstrate a correlation between histological features and atrial cardiomyopathy biomarkers in ischemic stroke, to better stratify ESUS patients. Materials and Methods. We enrolled a series of 114 consecutive subjects, over a period of three years. Demographic and clinical data was collected, besides specific data of interest for the study (presence of atrial cardiomyopathy biomarkers, HAVOC score). All the clots retrieved were stained and analyzed to quantify major components (red blood cells, platelets and fibrin, neutrophils). Univariate and multivariate analyses were performed. Results. Cerebral clot composition (in terms of red blood cells, platelets and fibrin) seem not to depend on the stroke etiology; conversely, thrombi retrieved from cardioembolic strokes present a higher presence of neutrophils (OR 3.25; 95% confidence interval 1.29 – 8.24; p= 0.01). In ESUS subjects, the presence of a first degree interatrial block as a marker of atrial cardiomyopathy seems to be related to a higher presence of neutrophils in the thrombus (p= 0.02); clots retrieved in ESUS patients with this characteristic, therefore, seem to be more similar to those retrieved in cardioembolic strokes. Conclusion. Cardioembolic strokes show cerebral thrombi richer in neutrophils when compared to strokes of other etiologies. No differences were observed regarding other clot components (red blood cells, platelets and fibrin). Presence of a first degree interatrial block seems to be a possible marker of atrial cardiomyopathy that could be used to stratify ESUS patients. Further studies with larger sample sizes are needed to confirm these findings.