Fibrinolytic factors and atherothrombotic events: epidemiological evidence

The fibrinolytic system is important in thrombus resolution at the site of atherosclerotic plaque rupture. The usual levels of plasma fibrinolytic fac tors have been hypothesized to be important in predicting atherothrombotic events. In this report, prospective clinical prospective epidemiological, a nd genetic epidemiological studies of fibrinolytic factors and incident car diovascular disease are reviewed. Many prospective studies have reported an unadjusted positive association between plasma fibrinolytic markers (eg, t issue plasminogen activator antigen or plasminogen activator inhibitor anti gen) and risk of cardiovascular disease. The association tends to be strong and demonstrate a dose-response, but often becomes statistically nonsignif icant after adjustment for other risk factors. About half of the genetic ep idemiological studies suggest that a polymorphism of a gene coding for fibr inolysis may be associated with cardiovascular disease, but that the relati ve risk is modest, at best. Thus, epidemiological evidence to date is incon clusive about whether impaired fibrinolysis may be a 'cause' of atherothrom botic events. In fact, alterations of plasma fibrinolytic factors might be a 'consequence' of atherosclerosis. At present, it seems premature to recom mend routine measurement of fibrinolytic factors to identify patients at ri sk of cardiovascular disease events. Some directions for future research on this topic are offered.