Fibrin D-dimer: a useful clinical marker of thrombogenesis?

Thrombus formation (thrombogenesis) is a process involving platelet adherence to the vessel wall (sometimes at sites of endothelial injury), platelet aggregation and release, thrombin generation and fibrin formation. In addition, it is also well recognized that the process of atherosclerosis is closely related to ongoing formation and organization of mural thrombi [ l , 21. Improved biochemical definition of the factors involved in thrombogenesis and newer assay techniques have allowed the clinical measurement of such factors in assessment of the process of thrombogenesis. The study of the possible mechanisms of thrombogenesis in conditions with a particular risk of thromboembolism is therefore feasible. Measurement of these plasma factors may allow the screening of patients in order to identify those most at risk of thromboembolism, and hence those who might benefit most from anti-thrombotic therapy. In addition, these plasma factors may provide prognostic information and enable monitoring of the eficacy of anti-thrombotic therapy. Such measurements also raise the possibility of developing new strategies in anti-thrombotic therapy. One marker which is attracting interest as an index of intravascular thrombogenesis is the plasma level of the fibrin D-dimer antigen. As fibrin D-dimer is considered to originate from cross-linked fibrin assembled during thrombus formation, a rise in fibrin D-dimer levels is indicative of thrombus formation. Plasma fibrin D-dimer assays are currently available from several manufacturers in clinical practice for the diagnosis of disseminated intravascular coagulation and venous thromboembolism. Recently, prospective studies have suggested a prognostic value of quantitative assays of plasma fibrin D-dimer in the prediction of arterial thrombosis; associations with atrial fibrillation and with other Prothrombin