OBJECTIVETo study the clinical implications of changes in plasma tissue factor (TF), tissue factor pathway inhibitor (TFPI) and factor VII (FVII) after the onset of acute myocardial infarction (AMI) and acute cerebral infarction (ACI).

METHODSSixty-nine patients with AMI, 71 with ACI and 50 age-matched healthy volunteers were enrolled in this study. Blood samples were obtained from the healthy subjects and from the patients at the early stage of AMI and ACI onset for examination of plasma TF and TFPI activity using chromogenic assay, and the plasma TF and TFPI antigens were measured by enzyme-linked immunosorbent assay (ELISA). The plasma FVII coagulation activity (FVII:C) was also measured, and the plasma FVIIa determined using soluble TF assay.

RESULTSCompared with the healthy control group, AMI patients had significantly enhanced plasma TF and TFPI activities and elevated TF and TFPI antigen levels (P<0.05), with also markedly increased FVIIa (P<0.05) but comparable FVII:C (P>0.05). In ACI patients, the plasma TF activity and antigen were obviously increased in comparison with the control group (P<0.05), but plasma TFPI activity and antigen were lowered (P<0.05), and both the FVII:C and FVIIa were markedly higher (P<0.05). Significant differences were noted in plasma TF and TFPI activities and their antigen levels as well as in FVII:C, but not in FVIIa between AMI and ACI patients.

CONCLUSIONV Following the onset of AMI and ACI, TF pathway is initiated and the risk of thrombogenesis increases, and the assessment of TF pathway is therefore of value for understanding the development of the condition.