ABSTRACT D‐dimer defines degradation products derived from the proteolysis mediated by plasmin on cross‐linked fibrin. The evidence‐based use of D‐dimer in some conditions has been consolidated. Currently, however, there is an entrenched prescription of D‐dimer testing to screen otherwise healthy subjects that may induce prescribing physicians to start time‐consuming diagnostic procedures that may generate patient anxiety/distress and often fail to reach meaningful conclusions for patients' management. To make things worse, the incidental finding of unexplained elevated D‐dimer is often, and inadvertently, taken as an index of venous thromboembolism (VTE) that may induce unnecessary initiation of thromboprophylaxis. Finally, population studies showed that elevated D‐dimer is variably associated with arterial thrombosis. However, the above studies do not allow establishing a direct causal relationship between elevated D‐dimer and disease, which makes D‐dimer measurement hardly applicable in individual patients. With this as background, the Italian Society on Thrombosis and Hemostasis appointed a panel to prepare a guidance on the use of D‐dimer based on the literature and expert opinion. The main conclusions of the panel can be summarized as follows: (i) D‐dimer can be reliably used in combination with pre‐test clinical probability to exclude VTE in symptomatic outpatients. (ii) It may help establish the optimal duration of secondary VTE prevention with vitamin K antagonists, although the panel felt that this area needs further investigation when dealing with direct oral anticoagulants. (iv) The use of D‐dimer in combination with the pre‐test probability score can be used to safely rule out acute aortic syndromes in the emergency setting without further imaging tests.
Tripodi et al. (2025) studied this question.