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D-dimers are specific degradation products of cross-linked fibrin that are
released when the endogenous fibrinolytic system attacks the fibrin matrix of
fresh venous thromboemboli. The absence of a raised concentration of D-dimer
implies that there is no fresh thromboembolic material undergoing dissolution
in the deep veins or in the pulmonary arterial tree. There is evidence
that a normal D-dimer assay result was useful for ruling out pulmonary embolism
(PE) in patients with a low pretest probability of PE or a nondiagnostic V/Q scan.
A d-dimer below a certain cut point rules out PE with a high predictive value,
at least in patients with a low or moderate clinical probability (4)
Conditions in which there may be a raised D-dimer include:
- pulmonary embolism
- deep vein thrombosis
- disseminated intravascular coagulation
- postoperatively
More detailed information concerning other causes and factors affecting D-dimer
levels is included in the linked item.
Notes:
- D-dimer levels and prediction of recurrent VTE
- a systematic review was undertaken (5)
- patients who had completed at least 3 months of anticoagulation
for a first episode of unprovoked (idiopathic) VTE and after approximately
2 years of follow-up, a negative D-dimer result was associated with
a 3.5% annual risk for recurrent disease, whereas a positive D-dimer
result was associated with an 8.9% annual risk for recurrence
Reference:
- Evidence Based Medicine (1999); 4 (3): 90.
- Moser K (1994). Diagnosing pulmonary embolism. BMJ (309): 1525-6.
- Ann
Emerg Med 2002 Aug;40(2):133-44
- Evidence Based Medicine (2002); 8(1):29.
- Verhovsek
M et al. D-dimer to predict recurrent disease after stopping anticoagulant
therapy for unprovoked venous thromboembolism.Ann Intern Med. 2008 Oct 7;149(7):481-90
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