Fibrinogen in ischaemic heart disease.

Fibrinogen contributes to both pathological and clinical manifestations of ischaemic heart disease (IHD). Several cross-sectional angiographic studies have shown correlations between the fibrinogen level and the extent of coronary artery disease. The largest of these studies suggests that this relationship is due mainly to luminal occlusion, strengthening the evidence that high fibrinogen levels are thrombogenic. The growing number of prospective studies that have included fibrinogen measurements consistently show a direct, independent and statistically significant association between fibrinogen level and the subsequent incidence of IHD, this association being about as strong as the relation between cholesterol and IHD, for example. The fibrinogen level is also associated with the recurrence of IHD in those who have survived a myocardial infarction and with the onset and recurrence or progression of cerebrovascular disease and lower extremity arterial disease. Besides a contribution to coronary artery changes, high fibrinogen levels predispose to IHD through influences on blood and plasma viscosity, platelet aggregability and the amount of fibrin produced when coagulation is initiated. Progress towards the standardization of methods for measuring fibrinogen increasingly justifies its inclusion in the IHD risk profile. Establishing the value of agents that lower fibrinogen levels is now a high research priority, mainly for clinical reasons but also as part of the evidence for clarifying the nature of the association of raised levels with arterial disease.