Factor VII hyperactivity in acute myocardial thrombosis. A relation to the coagulation activation

It has been shown that coagulation factor VII (FVII) has an increased coagulant activity (FVIIc) in cardiovascular high risk patients and that it is a important risk factor for the development of ischaemic heart disease (IHD) and cardiovascular death. In this study, we measured FVII coagulant (FVIIc) and immunological (FVIIag) activities during the acute phase of unstable angina (UA) and acute uncomplicated and complicated myocardial infarction (AMI). We have also studied its changes in relation to thrombin formation and coagulation activation, as assessed by determination of thrombin-antithrombin circulating complexes (T-AT) at the same time. Our results show a marked increase in FVIIc in all patients, with highest significant levels in complicated AMI. In fact, this increase was also different between groups, complicated AMI showing a significant degree of increase in FVIIc in relation to UA and uncomplicated AMI. FVIIag did not vary between groups and controls, implicating a progressive activation of FVII. As expected, we found comparable levels of T-AT in UA and in AMI patients, suggesting that a common thrombotic process is involved in both situations. FVIIc was strongly correlated to T-AT in all patients (r = 0. 750; p less than 0.001) and also within groups. This study underlines the important positive contribution of FVIIc to IHD and to the prognosis of its thrombotic acute events, and shows that the increase in FVII activity is associated with an increase of a thrombotic marker (thrombin-antithrombin). Further studies are needed to evaluate if FVII activation is the cause or the consequence of the thrombotic processes.