D-dimer
In medicine, D-dimer is a fibrin degradation product after coagulation. It may be elevated in patients with pulmonary embolism or deep venous thrombosis.
Immunologic tests for d-dimer are generally use immunoassays such as enzyme-linked immunosorbent assay or serologic tests such as agglutination tests. The immunoassays (more specifically, enzyme-linked immunosorbent assay) tend to be more sensitive.[1]
D-dimer may be under-used in patients at low risk of pulmonary embolism.[2]
Diagnostic accuracy
Systematic reviews have studied the diagnostic accuracy.[1][3][4]
In interpretation of the d-dimer, for patients over age 50 a value of ageX10 may be abnormal.[5][6][7]
| sensitivity | specificity | |
|---|---|---|
| Immunoassays | ||
| Elisa such as VIDAS™ | 95%[1] 96%[4] |
44%[1] 39%[4] |
| Agglutination tests | ||
| Latex agglutination such as Tinaquant™ | 89%[1] 96%[4] |
45%[1] 43%[4] |
| Whole blood hemagglutination test such as SimpliRED™ | 78%[1] 87%[4] |
74%[1] 66%[4] |
Using D-dimer to determine duration of anticoagulation treatment
An abnormal D-dimer level at the end of treatment might signal the need for continued anticoagulation with warfarin among patients with embolism and thrombosis such as a first unprovoked pulmonary embolism. If the D-dimer is abnormal, anticoaguation should be continued, if the D-dimer is normal, the duration of treatment is uncertain.[8] In an observation study that collected the D-dimer before stopping anticoagulation, the D-dimer was not as predictive.[9]
Diagnosis
Deep venous thrombosis
"Deep-vein thrombosis can be ruled out in a patient who is judged clinically unlikely to have deep-vein thrombosis and who has a negative D-dimer test" according to a randomized controlled trial. [10]
Using a single threshold value of the d-dimer to indicate abnormal may not be optimal. Alternatives are:[11]
- age in years×10 μg/L in patients aged >50 years
- 750 μg/L in patients aged ≥60 years
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Stein PD, Hull RD, Patel KC, et al. (April 2004). "D-dimer for the exclusion of acute venous thrombosis and pulmonary embolism: a systematic review". Ann. Intern. Med. 140 (8): 589–602. PMID 15096330. [e]
- ↑ Venkatesh AK, Kline JA, Courtney DM, Camargo CA, Plewa MC, Nordenholz KE et al. (2012). "Evaluation of Pulmonary Embolism in the Emergency Department and Consistency With a National Quality Measure: Quantifying the Opportunity for ImprovementEvaluation of Pulmonary Embolism in ER.". Arch Intern Med: 1-5. DOI:10.1001/archinternmed.2012.1804. PMID 22664742. Research Blogging.
- ↑ Goodacre S, Sampson FC, Sutton AJ, Mason S, Morris F (2005). "Variation in the diagnostic performance of D-dimer for suspected deep vein thrombosis.". QJM 98 (7): 513-27. DOI:10.1093/qjmed/hci085. PMID 15955795. Research Blogging.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 Di Nisio M, Squizzato A, Rutjes AW, Büller HR, Zwinderman AH, Bossuyt PM (February 2007). "Diagnostic accuracy of D-dimer test for exclusion of venous thromboembolism: a systematic review". J. Thromb. Haemost. 5 (2): 296–304. DOI:10.1111/j.1538-7836.2007.02328.x. PMID 17155963. Research Blogging.
- ↑ Schouten HJ, Geersing GJ, Koek HL, Zuithoff NP, Janssen KJ, Douma RA et al. (2013). "Diagnostic accuracy of conventional or age adjusted D-dimer cut-off values in older patients with suspected venous thromboembolism: systematic review and meta-analysis.". BMJ 346: f2492. DOI:10.1136/bmj.f2492. PMID 23645857. PMC PMC3643284. Research Blogging.
- ↑ van Es J, Mos I, Douma R, Erkens P, Durian M, Nizet T et al. (2012). "The combination of four different clinical decision rules and an age-adjusted D-dimer cut-off increases the number of patients in whom acute pulmonary embolism can safely be excluded.". Thromb Haemost 107 (1): 167-71. DOI:10.1160/TH11-08-0587. PMID 22072293. Research Blogging.
- ↑ Douma RA, le Gal G, Söhne M, Righini M, Kamphuisen PW, Perrier A et al. (2010). "Potential of an age adjusted D-dimer cut-off value to improve the exclusion of pulmonary embolism in older patients: a retrospective analysis of three large cohorts.". BMJ 340: c1475. DOI:10.1136/bmj.c1475. PMID 20354012. Research Blogging.
- ↑ Palareti G, Cosmi B, Legnani C, et al (2006). "D-dimer testing to determine the duration of anticoagulation therapy". N. Engl. J. Med. 355 (17): 1780-9. DOI:10.1056/NEJMoa054444. PMID 17065639. Research Blogging.
- ↑ Rodger MA, Kahn SR, Wells PS, Anderson DA, Chagnon I, Le Gal G, et al. Identifying unprovoked thromboembolism patients at low risk for recurrence who can discontinue anticoagulant therapy. CMAJ. 2008 Aug 26;179(5):417-426.
- ↑ Wells PS, Anderson DR, Rodger M, Forgie M, Kearon C, Dreyer J et al. (2003). "Evaluation of D-dimer in the diagnosis of suspected deep-vein thrombosis.". N Engl J Med 349 (13): 1227-35. DOI:10.1056/NEJMoa023153. PMID 14507948. Research Blogging. Review in: ACP J Club. 2004 May-Jun;140(3):67
- ↑ Schouten HJ, Koek HL, Oudega R, Geersing GJ, Janssen KJ, van Delden JJ et al. (2012). "Validation of two age dependent D-dimer cut-off values for exclusion of deep vein thrombosis in suspected elderly patients in primary care: retrospective, cross sectional, diagnostic analysis.". BMJ 344: e2985. DOI:10.1136/bmj.e2985. PMID 22674922. Research Blogging.