Abstract 9570: Different Distribution of CD163 Positive Macrophages in Thrombus Retrieved From Infarct-Related Artery: Atherothrombosis vs. Cardiogenic Thrombosis, Pathological Analyses From the MITO Study

Abstract

Introduction: Diagnosis of cardiogenic thrombosis is important because anticoagulant therapy is recommended for its secondary prevention. However, it is difficult to make a clear distinction in the pathogenesis between atherothrombosis and cardiogenic thrombosis. Hypothesis: Role of macrophage in thrombus formation is different between atherothrombosis and cardiogenic thrombosis. Methods: The Macrophage in Thrombus (MITO) study is a prospective observational study examining pathological and biological differences of arterial thrombus between atherothrombosis and cardiogenic thrombosis. Patients with ST elevation myocardial infarction (STEMI) or acute ischemic stroke (AIS) whose solid thrombus could be retrieved from the infarct-related artery were enrolled. Patients were divided into 2 groups as follows; STEMI with sinus rhythm: Group A (presumed atherothombosis) and AIS with atrial fibrillation (presumed cardiogenic thrombosis): Group C, and compared macrophage score as follows; 1:almost no macrophages detected byх40; 2:difficult to detect the macrophages in х20 but detected by х40; and 3:easy to detect macrophages in х20 in the thrombus. Serum levels of soluble CD163 were measured all the patients. Results: The score for CD163 positive macrophage of Group C (n=33) was significantly higher than that of Group A (n=32) (p<0.01): Figure. Serum level of soluble CD163 in Group C (median 603 ng/ml, IQR 405, 788) tended to be higher than that in Group A (median 520 ng/ml, IQR: 314, 634); p=0.08. Conclusions: CD163 positive macrophages are more involved in the thrombus formation of cardiogenic thrombus than that of atherothrombosis. Detection of CD163 positive macrophages are likely to help discriminate between atherothrombosis thrombus versus cardiogenic thrombus.