(TCP006) USE OF D-DIMER FOR THE EXCLUSION OF NEW PULMONARY EMBOLISM IN ANTICOAGULATED PATIENTS; A MULTICENTER RETROSPECTIVE STUDY

Background: The use of plasma D-dimer level to exclude pulmonary embolism (PE) in low-intermediate risk non-anticoagulated patients has been well studied. However, its use for patients on chronic direct-acting oral anticoagulant (DOAC) therapy is unclear. We aimed to evaluate D-dimer performance for the exclusion of PE among patients on DOACs who presented to the emergency department (ED) and underwent lung imaging for clinically suspected PE.

METHODS AND RESULTS: Patients aged ≥ 18 years on DOAC therapy who presented to the ED between January 2010 and June 2019 and had, in one visit (or in two visits within two days), a plasma D-dimer measurement and an imaging test to assess PE (CT pulmonary angiography or ventilation-perfusion scintigraphy) were included. The primary outcome was to evaluate the diagnostic accuracy of a negative D-dimer in the exclusion of a new PE.

Our study included 109 patients. Only four patients (3.7%) had a new diagnosis of PE, of which two had active cancer. The sensitivity of abnormal conventional or age adjusted D-dimer thresholds to detect PE in this population was 100.0% (95%CI 39.8-100.0) for both thresholds, whilst the negative predictive value to exclude PE in this population was 100.0% (95%CI 91.8-100.0 and 93.8-100.0 respectively for each D-dimer threshold).

Conclusion: In patients on chronic DOAC therapy, plasma D-dimer level appears to have a high sensitivity and a high negative predictive value. This study suggests a possible role of plasma D-dimer level in the exclusion of PE among patients on DOAC therapy with a clinical suspicion of PE. However, these findings are hypothesis-generating only, and further studies are required.

Lay Abstract Content: We aimed to evaluate D-dimer performance for the exclusion of PE among patients on DOACs who presented to the emergency department (ED) and underwent lung imaging for clinically suspected PE.