Coronary thrombus composition: Links with inflammation, platelet and endothelial markers

Abstract

Objectives: We investigated whether markers of platelet, neutrophil and endothelial activation, plasma fibrin clot properties and patient clinical profile may characterize coronary thrombus composition in ST-segment elevation myocardial infarction (STEMI) patients. Methods: A total of 40 intracoronary thrombi obtained 4.0–16.5 h since chest pain onset by manual aspiration during primary coronary intervention (PCI) were assessed using scanning electron microscopy. Plasma fibrin clot permeation coefficient (K_s) and clot lysis time (CLT), together with platelet and endothelial activation, fibrinolysis, and inflammation markers, were measured ex vivo in 16 patients on admission (pre-PCI group) and on the next morning in 24 patients (post-PCI group). Results: Fibrin, erythrocyte, platelet and white blood cell content in the thrombi were estimated at 49.1%, 24.2%, 11.6% and 3.7% respectively. In the pre-PCI group, in addition to fibrinogen, P-selectin and plasminogen activator inhibitor-1 were positively correlated with thrombus fibrin content. In the post-PCI group, in addition to von Willebrand factor antigen (vWF:Ag), soluble CD40 ligand and myeloperoxidase (MPO) were positively correlated with thrombus fibrin content. After adjustment for fibrinogen and onset-to-thrombectomy time circulating vWF:Ag in both groups, and MPO and P-selectin in the pre-PCI group were the independent predictors of fibrin-rich intracoronary thrombus presence. Other predictors were renal impairment, arterial hypertension and time from symptom onset to thrombus aspiration in all patients. Conclusions: In STEMI patients coronary thrombus composition is partly characterized by plasma markers of platelet, neutrophil and endothelial activation, with a varying contribution of these factors over time.