Prospective study of fibrinolytic markers and venous thromboembolism

Prior research has conflicted on whether increased levels of plasma fibrinolytic factors may identify patients at risk of venous thromboembolism (VTE). We therefore performed a nested case-control study of VTE within two prospective population-based studies. In 308 participants who developed VTE and 640 controls, we measured PAI-1 antigen, tPA/PAI-1 complex, plasmin-α₂-antiplasmin (PAP), and the PAI-1 -675 4G/5G promoter polymorphism on pre-event blood samples. There was no overall association between any of these fibrinolytic variables and VTE, after adjustment for age or for multiple VTE risk factors. There was weak evidence for an interaction of PAP with elevated factor VIIIc and elevated D-dimer in augmenting VTE risk. We conclude that, for the most part, these fibrinolytic markers do not identify healthy subjects at risk for VTE.