First approach to distinguish between cardiac and arteriosclerotic emboli of individual stroke patients applying the histological THROMBEX-classification rule

Abstract

Endovascular treatment of strokes caused by large vessel occlusion enables the histopathological investigation of the retrieved embolus, possibly providing a novel opportunity to contribute to the diagnostic workup of etiology and to define secondary prevention measures in strokes with uncertain genesis. We aimed to develop a classification rule based on pathophysiological considerations and adjustment to reference thrombi for distinction between cardiac and arteriosclerotic emboli and to validate this classification rule on a patient cohort. From 125 patients with stroke due to large vessel occlusion and thrombectomy, 82 patients with known etiology (55 cardioembolic and 27 arterioembolic strokes) were included. The corresponding emboli were histologically evaluated by two raters blinded to the etiology of stroke by means of a novel classification rule. Presumed etiology and classification results were compared. Agreement concerning cardiac emboli was 72.2% (95% CI: 58.4–83.5) for rater I and 78.2% (95% CI: 65.0–88.2) for rater II. Agreement concerning arteriosclerotic emboli was 70.4% (95% CI: 49.8–86.3) for rater I and 74.1% (95% CI: 53.7–88.9) for rater II. Overall agreement reached 71.6% (95% CI: 60.5–81.1) for rater I and 76.8% (95% CI: 66.2–85.4) for rater II. Within the limits of generally restricted accuracy of histological evaluations, the classification rule differentiates between cardiac and arteriosclerotic emboli of acute ischemic stroke patients. Further improvement is needed to provide valuable complementary data for stroke etiology workup.

Thrombus composition and thrombolysis resistance in stroke

“…Considering the importance of thrombus composition and structure in IVT resistance, identifying factors that influence these parameters may help better predict response to IVT. The determinants are most likely multifactorial, encompassing stroke etiology (eg, cardioembolic vs large artery atherosclerosis) [ 131 , 132 ] and underlying conditions (eg, cancer) [ 133 ], risk factors, comorbidities, and inflammation, all of which factors can be interrelated. With respect to etiology, there is converging evidence that AIS thrombi from cardioembolic origin have higher leukocyte, DNA, and NET content as compared with AIS thrombi linked to large artery atherosclerosis [ 82 , 131 , 134 , 135 ].…”