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Safety of D‐dimer testing as a stand‐alone test for the exclusion of deep vein thrombosis as compared with other strategies
Author(s) -
Fronas S. G.,
Wik H. S.,
Dahm A. E. A.,
Jørgensen C. T.,
Gleditsch J.,
Raouf N.,
Klok F. A.,
Ghanima W.
Publication year - 2018
Publication title -
journal of thrombosis and haemostasis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.947
H-Index - 178
eISSN - 1538-7836
pISSN - 1538-7933
DOI - 10.1111/jth.14314
Subject(s) - d dimer , medicine , deep vein , thrombosis , emergency department , surgery , radiology , emergency medicine , psychiatry
Essentials The aim of deep vein thrombosis (DVT) diagnostic work‐up is to maximize both safety and efficiency. We explored whether D‐dimer is safe and efficient as a stand‐alone test to exclude DVT. Our findings suggest it is a safe, efficient and simplified diagnostic strategy. The safety of age‐adjusted D‐dimer as a stand‐alone test requires further investigation.Summary Background Several strategies for safely excluding deep vein thrombosis ( DVT ) while limiting the number of imaging tests have been explored. Objectives To determine whether D‐dimer testing could safely and efficiently exclude DVT as a stand‐alone test, and evaluate its performance as compared with strategies that incorporate the Wells score and age‐adjusted D‐dimer. Patients/Methods We included consecutive outpatients referred with suspected DVT to the Emergency Department at Østfold Hospital, Norway. STA ‐Liatest D‐Di PLUS D‐dimer was analyzed for all patients. Patients with a D‐dimer level of ≥ 0.5 μg mL −1 were referred for compression ultrasonography ( CUS ). In patients with a D‐dimer level of < 0.5 μg mL −1 , no further testing was performed and anticoagulation was withheld. Patients were followed for 3 months for venous thromboembolism ( VTE ). Results Of the 913 included patients, 298 (33%) had a negative D‐dimer result. One hundred and seventy‐three patients (18.9%) were diagnosed with DVT at baseline. One of 298 patients had DVT despite having a negative D‐dimer result, resulting in a failure rate of 0.3% (95% confidence interval [ CI ] 0.1–1.9%). Adding the modified Wells score would have yielded a failure rate of 0.0% (95% CI 0.0–1.8%) while necessitating 87 more CUS examinations. Age‐adjusted D‐dimer as a stand‐alone test would have necessitated 80 fewer CUS examinations than fixed D‐dimer as a stand‐alone test, at the cost of a failure rate of 1.6% (95% CI 0.7–3.4%). Conclusions This outcome study shows that a negative high‐sensitivity D‐dimer result safely excludes DVT in an outpatient population, and necessitates fewer CUS than if used in combination with Wells score. The safety of stand‐alone age‐adjusted D‐dimer needs further assessment in prospective outcome studies.