American Journal of Emergency Medicine
Volume 28, Issue 4 , Pages 450-453, May 2010

Risk of venous thromboembolism in patients with borderline quantitative D-dimer levels

  • Taku Taira, MD

      Affiliations

    • Bellevue/NYU Medical Center New York, NY 10016, USA
    • ,
  • Breena R. Taira, MD

      Affiliations

    • Department of Emergency Medicine, Stony Brook University Medical Center, Stony Brook, NY 11794-8350, USA
    • Corresponding Author InformationCorresponding author. Tel.: +1 631 444 8351.
    • ,
  • Matt Carmen, MD

      Affiliations

    • Department of Emergency Medicine, Stony Brook University Medical Center, Stony Brook, NY 11794-8350, USA
    • ,
  • Jasmine Chohan, BA

      Affiliations

    • Department of Emergency Medicine, Stony Brook University Medical Center, Stony Brook, NY 11794-8350, USA
    • ,
  • Adam J. Singer, MD

      Affiliations

    • Department of Emergency Medicine, Stony Brook University Medical Center, Stony Brook, NY 11794-8350, USA

Received 5 September 2008; received in revised form 23 December 2008; accepted 22 January 2009. published online 08 February 2010.

Abstract 

Objective

The lower threshold for D-dimer in evaluating patients with low clinical risk of venous thromboembolism (VTE) ranges from 200 to 500 ng/mL. We compared the rates of VTE in patients based on D-dimer values. We hypothesized that the rate of VTE in low-risk patients with D-dimer levels less than 500 would be less than 1%.

Methods

Study Design: This was a retrospective chart review: Setting: The study was performed in a academic, suburban emergency department (ED). Subjects: Emergency department patients with suspected VTE and D-dimer obtained were included in the study. D-dimer assay: The D-dimer assay is a quantitative instrumentation latex suspension of plasma specimens. Outcomes: Presence of VTE within 30 days of ED visit. Data Analysis: Assuming a 0% event rate in patients with D-dimer levels between 200 and 500 ng/mL, a sample of 450 patients would result in a 95% confidence interval upper limit of 0.6%.

Results

There were 1270 ED patients with suspected VTE in which D-dimer levels were performed between October 2005 and October 2006. Patient mean age was 47.8 ± 19.3 years; 63.2% were female, 78.2% were white. Of all D-dimer levels, 497 (39.1%) were less than 200 ng/mL, 479 (37.7%) were between 200 and 500 μg/mL, and 294 (23.1%) were greater than 500 ng/mL. There were no VTE events diagnosed in any of the patients with D-dimer levels less than 200 ng/mL. Four patients with D-dimer levels between 200 and 500 μg/mL had a pulmonary embolism on computed tomography angiography. Of these 4 patients, 3 had moderate clinical risk based on Well's criteria and one had a false-positive computed tomography. There were no cases of VTE in the remaining 475 patients (0%; 95% confidence interval 0%-0.6%).

Conclusion

The rate of confirmed VTE in low-risk patients with D-dimer levels between 200 and 500 ng/mL is very low. Low-risk patients with suspected VTE with D-dimer levels less than 500 ng/mL might not require additional testing.

To access this article, please choose from the options below

Login to an existing account or Register a new account.

  • Purchase this article for 31.50 USD (You must login/register to purchase this article)

    Online access for 24 hours. The PDF version can be downloaded as your permanent record.

  • Subscribe to this title

    Get unlimited online access to this article and all other articles in this title 24/7 for one year.

  • Claim access now

    For current subscribers with Society Membership or Account Number.

  • Visit SciVerse ScienceDirect to see if you have access via your institution.
 

PII: S0735-6757(09)00047-3

doi:10.1016/j.ajem.2009.01.023

American Journal of Emergency Medicine
Volume 28, Issue 4 , Pages 450-453, May 2010

Article Tools