Patients with ischaemic heart disease have high levels of plasminogen activator inhibitor type 1 (PAI-1). These levels can constitute an independent thrombotic risk factor. In addition, PAI-1 synthesis is greater in the atherosclerotic vessels than in the normal vessels and this can also constitute an atherogenic risk factor. There is a good correlation between insulinaemia and PAI-1, but it has not been demonstrated that the circulating level of PAI-1 depends exclusively on insulinaemia. The increased levels of PAI-1 correlate with other coronary risk factors, especially hypertriglyceridaemia, but high PAI-1 levels are also found in normolipaemic patients. Vascular synthesis of PAI-1 can be promoted by high levels of circulating lipoprotein a. Finally, an exercise programme can increase the fibrinolytic activity of heart disease patients towards normal.