D-Dimers are specific cross-linked fibrin derivatives that are the product of plasmin-mediated fibrinolytic degradation. D-Dimer results from complete breakdown of the clot. They are an excellent marker of fibrinolytic activity. Elevated levels of D-Dimer are an indication of active fibrinolysis and have been shown in patients with heart attacks, disseminated intravascular coagulation (DIC), deep vein thrombosis (DVT), and pulmonary embolism. A D-Dimer test can also be used to check how well a treatment is working.