Deep vein thrombosis: d-dimer coud not safely rule it out.

Clinical bottom line (level 2b)

  1. In patients with suspected deep vein thrombosis or pulmonary embolism, d-dimer tests could not safely rule them out.
  2. A negative quantitative ELISA may help to rule them out.
  3. Test characteristics vary greatly in ability to detect VTE.
Freyburger et al: Thrombosis and Haemostasis 1998; 79: 32-37
Expires May 2003

The study

Setting: university hospital, France

100 patients (aged mean 56 years, 56% male) suspected deep vein thrombosis or pulmonary embolism

Independent blinded reference standard, applied in all patients from a consecutive inappropriate spectrum.
Reference standard:
  • bilateral venogram and pulmonary angiogram
Diagnostic test: ELISA (Asserachrom; Enzymgost; Dimertest Gold); ELFA (Vidas D-dimer); immunofiltration (Nycocard D-dimer; Instant IA); red blood cell agglutination (Simplired); latex agglutination (Acculcot; D-dimer; FDP-Slidex)

The evidence

pre-test probability of venous thromboembolism: 50%, (95% CI: 40% to 60%)

diagnostic test venous thromboembolism no venous thromboembolism LR+
(95% CI)		 post-test probability LR-
(95% CI)		 post-test probability
ELISA (Asserachrom) 50 33 1.52
(1.24 to 1.85) 		60% 0.00
( to ) 		0%
ELISA (Enzymgost) 48 29 1.66
(1.30 to 2.11) 		62% 0.095
(0.024 to 0.38) 		9%
ELISA (Dimertest Gold) 49 24 2.04
(1.53 to 2.73) 		67% 0.039
(0.0054 to 0.27) 		4%
ELFA (Vidas D-dimer) 50 31 1.61
(1.30 to 2.00) 		62% 0.00
( to ) 		0%
Immunofiltration (Nycocard D-dimer) 50 50 1.00
(1.00 to 1.00) 		50% -
( to ) 		-%
immunofiltration (Instant IA) 43 26 1.65
(1.24 to 2.21) 		62% 0.29
(0.14 to 0.61) 		23%
red blood cell agglutination (SimpliRed) 38 16 2.38
(1.54 to 3.66) 		70% 0.35
(0.21 to 0.60) 		26%
latex agglutination (Acculot) 44 24 1.87
(1.37 to 2.55) 		65% 0.23
(0.10 to 0.50) 		18%
latex agglutination (D-dimer) 32 14 2.29
(1.40 to 3.73) 		70% 0.50
(0.33 to 0.75) 		33%
latex agglutination (FDP-Slidex) 36 16 2.25
(1.45 to 3.49) 		69% 0.41
(0.25 to 0.67) 		29%
total 50 50

  • One technician performed all tests. No estimate of variability possible

Comments

  1. Population of in-hospital patients may produce different test characteristics from the emergency department
  2. ELISA tests take several hours to perform. Faster studies are less specific. Note the wide variation in test characteristics.
  3. Unlike many d-dimer studies, investigations for both pulmonary embolism and deep vein thrombosis were performed.
  4. This study is too small to safely confirm that patients with a negative ELISA do not have a deep vein thrombosis.

Citation

  1. Freyburger G, Trillaud H, Labrouche S, et al: D-dimer strategy in thrombus exclusion: a gold standard study in 100 patients suspected of deep venous thrombosis or pulmonary embolism: 8 DD methods compared. Thrombosis and Haemostasis 1998; 79: 32-37
Contributor: Chris Ball and Clare Wotton, May 2000
Reviewer: Alex Gallus

Clinical Question.
Patient suspected DVT or PE
Intervention or Exposure d-dimer tests
Comparison venogram
Outcome diagnosis