WHAT IS D-DIMER TEST (FIBRIN DEGRADATION FRAGMENT) TEST?
An assay used to measure the amount of clot breakdown products specific for cross-linked fragments (D-dimer) derived from fibrin. A positive test indicates that thrombus formation is occurring. The test can be performed on whole blood without the removal or interference of fibrinogen. It does not distinguish lysis of physiologic and pathologic thrombi but distinguishes between fibrinogenolysis and fibrinolysis. The test has a 93% sensitivity for large emboli and a 50% sensitivity for smaller subsegmental emboli. A negative D-dimer test in the presence of a normal compression sound has a negative predictive value of 99%.