Thrombus formation and myocardial infarction are not uncommon in patients with coronary artery ectasia (CAE). In light of this, the present study aims to systemically evaluate the blood coagulation and fibrinolytic systems in CAE patients. In this study, we enrolled 30 patients with CAE, 30 patients with coronary atherosclerosis disease (CAD), and 29 subjects with normal coronary arteries (control). The coagulation system was evaluated using a routine coagulation function test performed in the hospital laboratory before coronary angiography, and measurements included prothrombin time, international normalized ratio, activated partial thromboplastin time, fibrinogen time, and thrombin time. The evaluation of the fibrinolytic system included measurements of D-dimer, euglobulin lysis time, plasminogen activator inhibitor 1, plasminogen, plasminogen activity assay, α1-antitrypsin (α1-AT), α2 plasmin inhibitor (α2-PI), and α2-macroglobulin (α2-MG). Alpha1-AT, α2-PI, and α2-MG also inhibit activities of 3 neutrophil serine proteases, namely human neutrophil elastase (HNE), cathepsin G (CG), and proteinase 3 (PR3); therefore, the plasma levels of these 3 proteinases were also evaluated.
In CAE patients, the circulating coagulation system was normal. For the fibrinolytic system, a decrease of plasminogen activity was observed (P = 0.029) when compared with CAD patients, and the concentrations of α1-AT (both P < 0.001), α2-PI (P = 0.002 and P = 0.025), and α2-MG (P = 0.034 and P < 0.001) were significantly elevated when compared with CAD patients and normal controls. Moreover, the plasma levels of HNE (both P < 0.001) and CG (P = 0.027 and 0.016) in CAE patients were also significantly higher than those of the CAD and control groups. There was no difference in plasma PR3 concentration among these 3 groups.
Disequilibrium of the coagulation/fibrinolytic system may contribute to thrombus formation and clinical coronary events in patients with CAE. The increased plasma concentrations of α1-AT, α2-PI, and α2-MG might provide beneficial effects by inhibiting the proteinases and restraining the ectatic process; on other hand, they led to unfavorable results by inhibiting plasmin and decreasing thrombus degradation in CAE patients.