Responses

Download PDFPDF

Accuracy of PE rule-out strategies in pregnancy: secondary analysis of the DiPEP study prospective cohort
Compose Response

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.
Author Information
First or given name, e.g. 'Peter'.
Your last, or family, name, e.g. 'MacMoody'.
Your email address, e.g. higgs-boson@gmail.com
Your role and/or occupation, e.g. 'Orthopedic Surgeon'.
Your organization or institution (if applicable), e.g. 'Royal Free Hospital'.
Statement of Competing Interests

PLEASE NOTE:

  • Responses are moderated before posting and publication is at the absolute discretion of BMJ, however they are not peer-reviewed
  • Once published, you will not have the right to remove or edit your response. Removal or editing of responses is at BMJ's absolute discretion
  • If patients could recognise themselves, or anyone else could recognise a patient from your description, please obtain the patient's written consent to publication and send them to the editorial office before submitting your response [Patient consent forms]
  • By submitting this response you are agreeing to our full [Response terms and requirements]
CAPTCHA
This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.

Vertical Tabs

Other responses

Jump to comment:

  • Published on:
    Could assay choice and sample storage explain the poor D-dimer sensitivity found by the DiPEP study?
    • Danny McLernon-Billows, Emergency Medicine Registrar Emergency Department, Great Western Hospital, Swindon, UK
    • Other Contributors:
      • Lucy Ellis, Emergency Medicine Registrar
      • Natalie Whitton, Emergency Medicine Consultant

    Having recently updated our Emergency Department guidelines for suspected PE in pregnancy, we read the secondary analysis of the DiPEP study with great interest.1 However, we were quite surprised at the poor overall D-dimer sensitivity. Only 66% (8/12) of PEs would have been identified based on the recommended positivity threshold of 400ng/ml. This is considerably lower than the pooled estimate of 97% (95% CI 96-98%) found by a recent meta-analysis evaluating D-dimer for PE, and largely explains the poor performance of the YEARS and Geneva algorithms in the DiPEP cohort.2

    This result does not seem to fit with the known physiology of pregnancy. We know that D-dimer levels increase throughout pregnancy, which should improve sensitivity and worsen specificity.3 To our knowledge there are no other studies demonstrating impaired sensitivity of D-dimer in pregnant vs. non-pregnant populations.

    The DiPEP authors note that most of the study participants had received anticoagulation before blood samples were taken, which can decrease D-dimer levels by up to 25% in the first 24 hours.1 They also note however, that this would be insufficient to explain all their false negative D-dimer results. Aside from random error, we wondered if anything else could explain the poor sensitivity.

    One feature of the DiPEP study that stood out to us was the D-dimer assay used. As a microplate ELISA assay, the Zymutest D-dimer should be very sensitive but we could not find any st...

    Show More
    Conflict of Interest:
    None declared.