D-dimer diagnostics: can I use any D-dimer assay? Bridging the knowledge-to-action gap

Area of Science:

• Clinical diagnostics
• Hematology
• Medical laboratory science

Background:

• D-dimer testing is vital for diagnosing venous thromboembolism (VTE), especially in outpatients.
• Current diagnostic strategies often combine D-dimer assays with clinical decision rules.
• Recent trials explore adjusting VTE exclusion thresholds based on patient age or clinical probability to improve efficiency.

Purpose of the Study:

• To review the role of D-dimer in VTE diagnosis and the impact of assay variability.
• To highlight findings from the 2023 International Society on Thrombosis and Haemostasis Congress regarding D-dimer diagnostics.
• To emphasize the need for harmonized D-dimer reporting and international collaboration.

Main Methods:

• Review of D-dimer's role in VTE diagnosis, focusing on outpatient settings.
• Analysis of recent management trials adjusting D-dimer thresholds.
• Examination of international external quality assurance data on D-dimer assay variability.

Main Results:

• Significant variability exists between different D-dimer assays worldwide, particularly at VTE exclusion thresholds.
• Assay variability can affect diagnostic accuracy and risk stratification for VTE.
• Adjusting D-dimer thresholds based on age or clinical probability can reduce unnecessary imaging.

Conclusions:

• D-dimer assay variability poses a challenge to accurate VTE diagnosis and risk stratification.
• Harmonization of D-dimer assays and reporting is urgently needed.
• International collaboration is essential to bridge the knowledge-to-action gap in D-dimer diagnostics.