Factor-VII activity and ischaemic heart disease: fatal and non-fatal events

The Northwick Park Heart Study suggested that factor VII activity might be more strongly related to fatal than non-fatal events of ischaemic heart disease. We used polychotomous logistic regression to model simultaneously the probabilities of fatal events, non-fatal myocardial infarction, dying of causes other than ischaemic heart disease and of events, non-fatal myocardial infarction, dying of causes other than ischaemic heart disease and of event-free survival. We followed 1459 white men aged 40-64 at recruitment for a mean period of 16.1 years. Of these, 92 died of ischaemic heart disease, 100 experienced non-fatal myocardial infarction, 173 died of other causes, and 1094 men were alive. Factor VII activity was strongly related to fatal events of ischaemic heart disease but not to non-fatal events (p = 0.008). A difference of 1 SD in factor VII activity was associated with a difference of nearly 50% in the probability of dying of ischaemic heart disease, but with no difference for non-fatal myocardial infarction. This contrast was not seen for smoking, cholesterol, blood pressure, fibrinogen or factor VIII activity. High levels of VII activity may influence outcome at the time of plaque rupture and tissue factor release by enhancing thrombin production and thus fibrin deposition and platelet aggregability. The apparently differential effect of factor VII activity on fatal and non-fatal ischaemic heart disease may have important screening and prophylactic implications.