[Change of tissue factor pathway ratio during attack in patients with acute myocardial infarction and its clinical significance].

This study was aimed to investigate the change of tissue factor pathway (TFP) ratio during the attack of acute myocardial infarction (AMI) and its clinical significance. Plasma recalcification time was assayed by manual operation. Plasma tissue factor (TF), TF pathway inhibitor (TFPI) antigen, FVII:Ag, activated FVII (FVIIa) and D-Dimer were measured by enzyme linked immunoabsorbent assay (ELISA). TF activity was determined by chromogenic assay, plasma FVII coagulation activity (FVII:C) was detected by one-stage system. Blood samples were taken from 59 patients with AMI and 84 healthy volunteers. The results indicated that (1) plasma recalcification time was significantly shorter in the AMI group than that in the control; (2) compared with the control, TF activity in AMI patients showed no significant change (p > 0.05); the antigen levels of TF and TFPI in patients with AMI were remarkably increased (p < 0.05), and the increment degree of TF was remarkably higher than that of TFPI, therefore the TF/TFPI ratio was enlarged; total TFPI (t-TFPI) and full-length TFPI (fl-TFPI) were significantly higher (p < 0.01), truncated TFPI (tr-TFPI) was significantly lower (p < 0.01); the TF/t-TFPI ratio was higher than that in normal group, the TF/t-TFPI ratio was lower than that in normal group (p < 0.01), but the TF/tr-TFPI and fl-TFPI/t-TFPI ratios in AMI group were more remarkably higher than that in control group (p < 0.01), the tr-TFPI/t-TFPI and tr-TFPI/fl-TFPI ratios were significantly lower (p < 0.01). (3) compared with the control, the levels of plasma FVIIa and FVII:C in AMI group were higher (p < 0.05), FVII:Ag did not significatly change; FVIIa/FVII: Ag ratio was more remarkably higher (p < 0.01), but the elevation of FVIIa/FVII:C and FVII:C/FVII:Ag ratios showed no significant change (p > 0.05); (4) plasma D-dimer was significantly higher, compared with the normal control (p < 0.01). It is concluded that TFP is initiated during the attack of AMI, suggesting the circulating blood in AMI patients is in hypercoagulable status, therefore the simultaneous detection of multiple coagulation factors is necessary for evaluating risk factors in AMI patients, and the use of ratio for reflecting hypercoagulable status and risk factors is more reliable to detect each of them separately.