Clinical trial NCT02507180: Safely Ruling Out Deep Vein Thrombosis in Pregnancy With the LEFt Clinical Decision Rule and D-Dimer
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.
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: Pregnancy
Deep Vein Thrombosis
Keywords: Clinical Decision Rule
Ultrasound
Suspected Deep Vein Thrombosis
D-Dimer
LEFt
Lead sponsor: Ottawa Hospital Research Institute
Sponsor class: OTHER
Collaborators: name: University Hospital, Geneva
name: Leiden University Medical Center
First posted: 2015-07-23
Enrollment: 366
Sex: FEMALE
Minimum age (years): 16
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: Unselected pregnant women presenting with suspected deep vein thrombosis

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.

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.

Eligibility criteria: 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.

Primary outcomes:
measure: Number of VTE diagnosed in patients deemed DVT "unlikely"
timeFrame: 3 months after presentation
Secondary outcomes:
measure: Number of VTE diagnosed in all patients
timeFrame: 3 months after presentation
measure: Proportion of women requiring CUS
timeFrame: Baseline
measure: Average number of CUS in pregnant women with suspected DVT
timeFrame: 7 days from initial presentation
Other outcomes:
Locations:
city: Murray
country: United States
facility: Intermountain Healthcare, Inc.
state: Utah
city: Calgary
country: Canada
facility: Foothills Medical Centre
state: Alberta
city: Edmonton
country: Canada
facility: Royal Alexandra Hospital
state: Alberta
city: Vancouver
country: Canada
facility: Children's and Women's Health Centre of British Columbia
state: British Columbia
city: Halifax
country: Canada
facility: Queen Elizabeth II Health Science Centre
state: Nova Scotia
city: Hamilton
country: Canada
facility: Hamilton Health Sciences Centre
state: Ontario
city: London
country: Canada
facility: London Health Sciences Centre
state: Ontario
city: Ottawa
country: Canada
facility: Ottawa Hospital Research Institute
state: Ontario
city: Toronto
country: Canada
facility: Sunnybrook Medical Hospital
state: Ontario
city: Montreal
country: Canada
facility: Jewish General Hospital
state: Quebec
city: Leiden
country: Netherlands
facility: Leiden University Medical Center
city: Geneva
country: Switzerland
facility: Hopitaux Universitaires de Geneve
Study officials:
affiliation: Ottawa Hospital Research Institute
name: Marc Rodger, MD
role: PRINCIPAL_INVESTIGATOR
affiliation: Hopitaux Universitaires de Geneve
name: Marc Righini, MD
role: PRINCIPAL_INVESTIGATOR
References: