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Safely Ruling Out Deep Vein Thrombosis in Pregnancy With the LEFt Clinical Decision Rule and D-Dimer (LEaD)

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ClinicalTrials.gov Identifier: NCT02507180
Recruitment Status : Unknown
Verified February 2020 by Ottawa Hospital Research Institute.
Recruitment status was:  Recruiting
First Posted : July 23, 2015
Last Update Posted : February 27, 2020
University Hospital, Geneva
Leiden University Medical Center
Information provided by (Responsible Party):
Ottawa Hospital Research Institute

Brief Summary:
This is prospective cohort study in pregnant women who present with signs and symptoms of possible deep vein thrombosis (DVT). All patients will have the same method of assessment of their DVT symptoms (the LEFt clinical decision rule will be applied and D-dimer test will be done) to determine if a compression ultrasound is required. All patients will be followed for a period of 3 months.

Condition or disease Intervention/treatment
Pregnancy Deep Vein Thrombosis Other: LEFt clinical decision rule

Detailed Description:

VTE is a leading cause of maternal death in the developed world. Suspected DVT in pregnancy is a common clinical problem faced by clinicians daily. The only validated method to exclude DVT in pregnancy requires leg vein CUS imaging. This imaging modality is costly and has limited availability (only available in radiology departments and, usually, only during weekday daytime hours) often necessitating referral to the emergency room for initiation of heparin injections until leg vein CUS can be obtained. A simple and seemingly powerful clinical decision rule (LEFt) and a simple blood test (D-dimer) may be promising to exclude DVT in pregnancy without the need for diagnostic imaging. Validating the safety of a simple, non-invasive, widely available approach to suspected DVT in pregnancy would be an important advance in maternal health.

A prospective cohort diagnostic management study in pregnant women with suspected DVT, with three-month follow-up for symptomatic VTE will take place in multiple centres throughout Canada and Europe.

After obtaining informed consent, all patient will have the LEFt clinical decision rule applied by the attending physician and will have D-Dimer testing (D-Dimer results of test performed within 24 hours will be accepted and do not need to be repeated).

Patients with an "unlikely" LEFt score of 0 or 1 point and a negative D-dimer will not undergo diagnostic imaging.

Patients with either a "likely" LEFt score of 2 or 3 points or a positive D-dimer will undergo either a single complete leg vein compression ultrasound (CCUS) (Day 1) or a serial proximal leg vein (CUS) (Day 1 and Day 7).

All patients will be followed for 3 months for symptomatic VTE.

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Study Type : Observational
Estimated Enrollment : 366 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: Safely Ruling Out Deep Vein Thrombosis in Pregnancy With the LEFt Clinical Decision Rule and D-Dimer: the LEaD Study. A Prospective Cohort Study.
Actual Study Start Date : September 2015
Estimated Primary Completion Date : September 2021
Estimated Study Completion Date : January 2022

Resource links provided by the National Library of Medicine

Group/Cohort Intervention/treatment
Pregnant women with suspected DVT
Pregnant women presenting with suspected DVT will have the LEFt clinical decision rule applied by the attending physician and will have a clinical D-dimer test done.
Other: LEFt clinical decision rule

The LEFt rule

Predictor Points Left leg symptoms +1 Extremity swelling (≥ 2 cm difference in calf circumference +1 First trimester symptom onset +1

Clinical probability Unlikely: 0 or 1 point Likely: > 1 point

Primary Outcome Measures :
  1. Number of VTE diagnosed in patients deemed DVT "unlikely" [ Time Frame: 3 months after presentation ]
    The primary outcome will be the number of VTE (distal or proximal DVT, sub-segmental or greater pulmonary embolism (PE), death attributable to VTE) documented during the three-month follow-up in those patients left untreated for DVT on the basis of the study's initial diagnostic management (see Figure 2) i.e. not doing CUS on patients with an "unlikely" LEFt score (0 or 1 points) and a negative D-dimer

Secondary Outcome Measures :
  1. Number of VTE diagnosed in all patients [ Time Frame: 3 months after presentation ]
    The number of major VTE events (any proximal DVT, segmental or greater PE, death attributable to VTE) documented during the 3-month follow-up in all patients. Some clinicians may not treat distal DVT or sub-segmental PE in pregnancy, instead following these patients with serial US imaging, and hence may prefer to focus on this outcome that excludes distal DVT and sub-segmental PE.

  2. Proportion of women requiring CUS [ Time Frame: Baseline ]
    The proportion of women requiring CUS using the study's diagnostic strategy (i.e. no imaging in patients with an "unlikely" LEFt score (0 or 1 points) and a negative D-dimer). We anticipate that an important proportion (>40%) of women will be able to avoid the need for CUS imaging based on safely excluding DVT on the basis of an "unlikely" LEFt (0 or 1) and a negative D-dimer. However, if this proportion is very low (<5%) this may argue against the widespread adoption of our proposed diagnostic management strategy even if it proves to be safe.

  3. Average number of CUS in pregnant women with suspected DVT [ Time Frame: 7 days from initial presentation ]
    The mean number of ultrasounds per patient with suspected DVT. In the study by Chan, validating serial CUS in pregnancy, the mean number of US per patient was 2.8630. We anticipate that we will be able to reduce this by >40% with our diagnostic approach.

Biospecimen Retention:   Samples Without DNA
At presentation, a blood sample will be collected for clinical D-dimer tested in real time and a sample will be collected and the plasma will be frozen for analysis at the end of study using Vidas D-dimer on all patient samples.

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   16 Years and older   (Child, Adult, Older Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population
Unselected pregnant women presenting with suspected deep vein thrombosis

Inclusion Criteria:

  1. Unselected pregnant women (as self-reported by patient and/or previously documented positive beta hCG on urine or serum pregnancy tests) with
  2. Suspected acute symptomatic deep vein thrombosis, defined as:

    1. New leg swelling or edema with onset in the last month or,
    2. New leg pain (buttock, groin, thigh or calf) with onset in the last month.

Exclusion Criteria:

  1. Below the age of legal consent in jurisdiction of residence (18 years old for Quebec and 16 years old for rest of Canada)
  2. Baseline imaging (imaging done after a minimum of 3 months of treatment for prior proximal DVT) not available if suspected recurrence in the same leg as prior
  3. Unable or unwilling to provide informed consent
  4. Concomitant symptoms of suspected pulmonary embolism (chest pain or shortness of breath or syncope/pre-syncope or unexplained tachycardia)
  5. Therapeutic anticoagulant more than 48 hours.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02507180

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Contact: Marc A Rodger, MD 514-843-1578 marc.rodger@mcgill.ca
Contact: Veronica Bates, BSc 613-737-8899 ext 71068 vebates@ohri.ca

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United States, Utah
Intermountain Healthcare, Inc. Not yet recruiting
Murray, Utah, United States
Contact: Scott Stevens, MD         
Principal Investigator: Scott Stevens, MD         
Canada, Alberta
Foothills Medical Centre Recruiting
Calgary, Alberta, Canada
Contact: Jessica Lee, BA         
Contact: Alissa Kazakoff, BSc         
Principal Investigator: Paul Gibson, MD         
Royal Alexandra Hospital Recruiting
Edmonton, Alberta, Canada
Contact: Shauna Littlefair, RN         
Principal Investigator: Rshmi Khurana, MD         
Canada, British Columbia
Children's and Women's Health Centre of British Columbia Recruiting
Vancouver, British Columbia, Canada
Contact: Frannie MacKenzie         
Principal Investigator: Wee-Shian Chan, MD         
Canada, Nova Scotia
Queen Elizabeth II Health Science Centre Recruiting
Halifax, Nova Scotia, Canada
Contact: Blaine Gallant, RN         
Principal Investigator: Sudeep Shivakumar, MD         
Canada, Ontario
Hamilton Health Sciences Centre Recruiting
Hamilton, Ontario, Canada
Contact: Carolyn Webb, RN         
Principal Investigator: Shannon Bates, MD         
London Health Sciences Centre Withdrawn
London, Ontario, Canada
Ottawa Hospital Research Institute Recruiting
Ottawa, Ontario, Canada
Contact: Veronica Whitham, BSc         
Principal Investigator: Marc Rodger, MD         
Sunnybrook Medical Hospital Withdrawn
Toronto, Ontario, Canada
Canada, Quebec
Jewish General Hospital Recruiting
Montreal, Quebec, Canada
Contact: Carla Strulovitch, RN         
Principal Investigator: Susam Kahn, MD         
Leiden University Medical Center Recruiting
Leiden, Netherlands
Contact: Erik Klok, MD         
Principal Investigator: Erik Klok, MD         
Hopitaux Universitaires de Geneve Recruiting
Geneva, Switzerland
Contact: Louise Riberdy, MD         
Principal Investigator: Marc Righini, MD         
Sponsors and Collaborators
Ottawa Hospital Research Institute
University Hospital, Geneva
Leiden University Medical Center
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Principal Investigator: Marc Rodger, MD Ottawa Hospital Research Institute
Principal Investigator: Marc Righini, MD Hopitaux Universitaires de Geneve
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Responsible Party: Ottawa Hospital Research Institute
ClinicalTrials.gov Identifier: NCT02507180    
Other Study ID Numbers: 20150546-01H
First Posted: July 23, 2015    Key Record Dates
Last Update Posted: February 27, 2020
Last Verified: February 2020
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Undecided

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by Ottawa Hospital Research Institute:
Clinical Decision Rule
Suspected Deep Vein Thrombosis
Additional relevant MeSH terms:
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Venous Thrombosis
Embolism and Thrombosis
Vascular Diseases
Cardiovascular Diseases