Pantep Angchaisuksiri is a Professor of Medicine and Chief of the Haemostasis and Thrombosis Unit in the Division of Haematology, Department of Medicine at Ramathibodi Hospital, Mahidol University in Bangkok, Thailand. He is co-director of the Bangkok International Haemophilia Training Centre of the World Federation of Haemophilia, and an Adjunct Associate Professor of Medicine at the University of North Carolina at Chapel Hill School of Medicine, North Carolina. Professor Angchaisuksiri is a medical graduate of Chulalongkorn University in Bangkok, Thailand, and was trained in Internal Medicine at Prince of Songkla University and Haematology at Mahidol University. He was also a clinical and postdoctoral fellow in Haematology/Oncology at the Medical College of Virginia in Richmond, Virginia and the University of North Carolina at Chapel Hill, School of Medicine, North Carolina, USA.  As an active clinician, Professor Angchaisuksiri works with patients with thrombosis, haemophilia, and other bleeding disorders, and has authored and co-authored papers relating to haemostasis and thrombosis in several leading international scientific journals. He is a council member of the International Society on Thrombosis and Haemostasis (ISTH) and the Asian-Pacific Society on Thrombosis and Haemostasis (APSTH), an associate editor of the ISTH journal Research and Practice in Thrombosis and Haemostasis (RPTH), an editorial board member of the journal Thrombosis Research, Journal Thrombosis, and Blood Research, and a member of several professional societies, including the American Society of Haematology, and the World Federation of Haemophilia.  He is also a Chairman of the ISTH Education and Outreach Committee, and a member of the ISTH Membership and Communications Committee.

Abstract

D-dimer is a biomarker of fibrin formation and degradation that can be measured in whole blood or in plasma. Healthy individuals have low levels of circulating D-dimer, whereas elevated levels are found in conditions associated with thrombosis. D-dimer has been extensively investigated for the diagnosis of venous thromboembolism (VTE) and is routinely used for this indication. A clinical suspicion of VTE mandates objective imaging testing to rule in or rule out the disease. D-dimer testing has gained wide acceptance for ruling out VTE in the outpatient population. A major limitation of D-dimer testing for diagnostic purposes is its limited usefulness for specific patient categories, such as elderly patients and pregnant women. Because D-dimer levels increase with age, using a fixed cutoff of 500 ng/mL may overestimate the probability of VTE in elderly patients, explaining the high percentage of false positive results observed. The ADJUST-PE study has shown that using an age-adjusted cutoff increased the proportion of elderly patients in whom pulmonary embolism (PE) could be safely excluded without imaging by fivefold. As a result, recent guidelines recommend using age-adjusted D-dimer when evaluating patients older than 50 years with suspected acute PE. For pregnant women, the application of the pregnancy-adapted YEARS diagnostic algorithm has recently been shown to result in safe exclusion of PE across all trimesters of pregnancy. D-dimer testing, combined with clinical probability assessment, can be used to safely exclude VTE, and is now regarded as a useful tool in the diagnostic strategy of VTE. D-dimer has also been evaluated to predict the recurrence of thrombosis after anticoagulation withdrawal for VTE, to determine the optimal duration of anticoagulation in VTE patients, and to identify medical patients at high risk for VTE. D-dimer level measured a month after stopping the anticoagulant may influence the treatment decision. An elevated baseline D-dimer level may identify acutely ill, hospitalised medical patients at high risk of VTE. D-dimer has also been evaluated for diagnosing and monitoring disseminated intravascular coagulation. In COVID-19 patients, D-dimer is a strong marker to predict thrombosis, and has been shown to help clinicians in assessing severity and prognosis of patients.