Relationship Between Fibrinogen Protein and Fibrinogen Function in Postmyocardial Infarction Patients

Abstract

The present study investigates the association between increases in the concentration and function of plasma fibrinogen in two groups of patients with chronic ischemic heart disease (11 with recurrent ischemic events and 19 free of these episodes) and in 34 healthy controls. The fibrinogen function index (fibrinogen function per unit of fibrinogen protein) (FgFI) was used as a measure of the fibrinogen clotting potential. The prothrombin fragment 1+2 (F1+2) and thrombin–antithrombin (TAT) were used as procoagulant markers. Plasma sialic acid (SA) was also evaluated as an inflammatory marker. No differences were found between FgFI (1.06±0.13 vs. 1.02±0.13), F1+2 (1.2±0.5 vs. 1.1±0.4 nmol/l) and TAT (2.5±1.3 vs. 2.5±0.7 μg/ml) in postinfarction patients without recurrent coronary ischemic events and the control group. However, postinfarction patients who suffered recurrent coronary ischemic events had significantly higher FgFI than patients without these symptoms (1.19±0.09 vs. 1.06±0.13), P<.01) and than the control group (1.19±0.09 vs. 1.02±0.13, P<.001). Moreover, the F1+2 (1.4±0.5 vs. 1.1±0.4 nmol/l, P<.05) and TAT (3.6±3.3 vs. 2.5±0.7 μg/ml, P<.05) were significantly higher in patients who suffered recurrent coronary ischemic events than in the control group. However, F1+2 and TAT were not different between patients with and without these symptoms. The fibrinogen protein (Fg-protein) concentration and high molecular weight fibrinogen (HMW-Fg) levels were significantly higher in both postinfarction patient groups than in the control group and in postinfarction patients with recurrent coronary ischemic events than in postinfarction patients without these symptoms. The plasma SA levels were significantly increased in postinfarction patients with and without recurrent coronary ischemia as compared with the control group. A positive correlation was found between fibrinogen and SA levels ( r=.5, P<.01). In conclusion, our study indicates that the procoagulant factors, among which we include fibrinogen, F1+2 and TAT play a very active role in recurrent ischemic events in postmyocardial infarction patients. High plasma concentrations of both fibrinogen and SA suggests that fibrinogen becomes elevated as a consequence of inflammatory processes. The FgFI as an indicator of clotting potential of fibrinogen appears to be associated with ischemic events in chronic coronary artery disease.