D-dimer is the most sensitive test for-

Robbins Basic Pathology (9th Edition),page no.85 Clotting also sets into motion a fibrinolytic cascade that moderates the ultimate size of the clot. Fibrinolysis is largely carried out by plasmin, which breaks down fibrin and interferes with its polymerization . The resulting fibrin split products (FSPs or fibrin degradation products) also can act as weak anticoagulants. Elevated levels of FSPs (most notably fibrin-derived D-dimers) can be used for diagnosing abnormal thrombotic states including disseminated intravascular coagulation (DIC) , deep venous thrombosis, or pulmonary thromboembolism