Atrial cardiopathy and thrombus composition in acute ischemic stroke: histological examination reveals insights into etiology and outcomes.

INTRODUCTION

In a subset of acute ischemic stroke (AIS) patients, particularly those with large-artery atherosclerosis (LAA) and atrial cardiopathy, multiple embolic sources may coexist. Histological analysis of thrombi presents an opportunity for discerning insights into both etiology and prognosis.

METHODS

In our investigation, we meticulously examined 97 retrieved thrombi through histological staining and immunohistological techniques.

RESULTS

Thrombi originating from patients diagnosed with atrial fibrillation (AF) (n = 43) presented notably elevated levels of fibrin (54.16 ± 18.57% vs. 36.07 ± 18.23%, P < 0.001) and neutrophil extracellular traps (NETs) [13.21 (9.42, 15.36)% vs. 7.96 (4.98, 15.13)%, P = 0.01], alongside reduced red blood cell content (35.09 ± 16.74% vs. 51.58 ± 19.67%, P < 0.001). Within the subgroup of AIS patients with LAA, those presenting with atrial cardiopathy (n = 29) presented higher platelet levels within the thrombus (12.44 (7.59, 19.25)% vs. 8.90 (0.60, 12.37)%, P = 0.04), with the association remaining significant after generalized linear model (GLM) adjustments (P = 0.004). Notably, NETs identified within the thrombus emerged as an independent prognostic indicator for poor outcomes, defined as the modified Rankin scale (mRS) score > 2 at 90 days (OR: 1.12, 95% CI: 1.02-1.25; P = 0.02).

CONCLUSIONS

These observations provide histopathological evidence supporting the presence of overlapping mechanisms contributing to thromboembolism that are potentially associated with underlying atrial cardiopathy. Consequently, histopathological evaluation of thrombi holds promise as a valuable tool for distinguishing between various etiologies and predicting clinical outcomes in AIS patients.