Elsevier

Clinical Radiology

Volume 57, Issue 1, January 2002, Pages 41-46
Clinical Radiology

Regular Article
The Use of a D-dimer Assay in Patients Undergoing CT Pulmonary Angiography for Suspected Pulmonary Embolus

https://doi.org/10.1053/crad.2001.0740Get rights and content

Abstract

PURPOSE: To assess the ability of a semi-quantitative latex agglutination D-dimer test Accuclot with bedside measurements of arterial oxygen saturation, respiratory and cardiac rates to exclude pulmonary embolism (PE) on computed tomographic pulmonary angiography (CTPA).

MATERIALS AND METHODS: All patients referred to our CT unit for investigation of suspected acute pulmonary embolism were enrolled. Pulse oximetery, respiratory rate, heart rate and blood sampling for D-dimer testing were carried out just before CT. A high resolution CT (HRCT) of the chest was followed by a CT pulmonary angiogram (CTPA). The images were independently interpreted at a workstation with cine-paging and 2D reformation facilities by three consultant radiologists blinded to the clinical and laboratory data. If positive, the level of the most proximal embolus was recorded. Discordant imaging results were re-read collectively and consensus achieved.

RESULTS: A total of 101 patients were enrolled. The CTPA was positive for PE in 28/101 (28%). The D-dimer was positive in 65/101 (65%). Twenty-six patients had a positive CT and positive D-dimer, two a positive CT but negative D-dimer, 39 a negative CT and positive D-dimer, and 34 a negative CT and negative D-dimer. The negative predictive value of the Accuclot D-dimer test for excluding a pulmonary embolus on spiral CT was 0.94. Combining the D-dimer result with pulse oximetry (normal SaO2  90%) improved the negative predictive value to 0.97. CONCLUSION: A negative Accuclot D-dimer assay proved highly predictive for a negative CT pulmonary angiogram in suspected acute pulmonary embolus. If this D-dimer assay were included in the diagnostic algorithm of these patients a negative D-dimer would have unnecessary CTPA rendered in 36% of patients. Burkill, G. J. C.et al. (2002). Clinical Radiology57, 41–46.

References (39)

  • Thorax

    (1997)
  • LR Goodman et al.

    Diagnosis of acute pulmonary embolism: time for a new approach

    Radiology

    (1996)
  • LA Charles et al.

    Evaluation of sensitivity and specificity of six D-dimer latex assays

    Arch Pathol Lab Med

    (1994)
  • H Bounameaux et al.

    Plasma measurement of D-dimer as a diagnostic aid in suspected venous thromboembolism: an overview

    Throm Haemostas

    (1994)
  • H Bounameaux et al.

    Measurement of plasma D-dimer for diagnosis of deep venous thrombosis

    Am J Clin Pathol

    (1989)
  • G Freyburger et al.

    D-dimer strategy in thrombosis exclusion

    Thromb Haemost

    (1998)
  • E Bernardi et al.

    D-dimer testing as an adjunct to ultrasonography in patients with clinically suspected deep vein thrombosis: prospective cohort study

    BMJ

    (1998)
  • J Herold Ch et al.

    Prospective evaluation of pulmonary embolism: initial results of the European multicentre trial (ESTIPEP)

    ECR Scientific Programme and Abstracts

    (1999)
  • P Egermayer et al.

    Usefulness of D-dimer, blood gas, and respiratory rate measurements for excluding pulmonary embolism

    Thorax

    (1998)
  • Cited by (23)

    • D-dimer in the diagnostic workup of suspected pulmonary thrombo-embolism at high altitude

      2012, Medical Journal Armed Forces India
      Citation Excerpt :

      The true benefits of the D-dimer assay lie in its NPV, which, in turn, translates into cost savings by eliminating the need for expensive imaging exams for negative low-risk patients. These patients are able to avoid invasive testing to rule out PTE.10 On the other hand, a positive result leads to additional testing to rule out or diagnose PTE.

    • Cost-effectiveness of strategies for diagnosing pulmonary embolism among emergency department patients presenting with undifferentiated symptoms

      2010, Annals of Emergency Medicine
      Citation Excerpt :

      Cutoff III (500 μg/L) represents the current widely used cutoff for the Vidas ELISA D-dimer (Table 2).14,16,30,37,40-42,44,77-80 We estimated computed tomographic venogram, compression ultrasonography, and computed tomographic pulmonary angiogram sensitivity and specificity from the literature.15,27,28,30,67,69,70,81-95 Ventilation-perfusion scan scan performance for pulmonary embolism at each ventilation-perfusion scan cutoff value considered (low, normal, intermediate) has been extensively studied.51,92,95-98

    • Clinical utility of d-dimer in patients with suspected pulmonary embolism and nondiagnostic lung scans or negative CT findings

      2004, Chest
      Citation Excerpt :

      The reason for this difference is likely the higher prevalence of acute or chronic conditions associated with fibrin generation among the inpatients, such as a history of recent surgery, myocardial infarction, or cancer (Table 1). Most previous studies of d-dimer in patients with suspected pulmonary embolism have included entirely or mostly outpatients,16171819202122 or failed to report the mix of inpatients and outpatients in the study population. The frequency of a negative d-dimer result among our outpatients is consistent with these prior studies.161718192021

    • Value of Quantitative D-dimer Assays in Identifying Pulmonary Embolism: Implications from a Sequential Decision Model

      2006, Academic Emergency Medicine
      Citation Excerpt :

      Initial CUS sensitivity for DVT was set at 0.93, with specificity of 0.98.14,32–35 Initial CTP sensitivity was 0.9, with specificity of 0.8.9,10,23,36–40 We performed extensive univariate and multivariate sensitivity analysis on CTP and CTV sensitivity and specificity.

    View all citing articles on Scopus
    f1

    Author for correspondence and guarantor of study: Dr S. P. G. Padley, Department of Radiology, Chelsea and Westminster Hospital, 369 Fulham Road, London, SW10 9NH, U.K. Fax: + 44 (0) 020 8746 8588; E-mail: [email protected]

    View full text