Pulmonary EmbolismEMPETNCT06320236
Emergency Medicine Pulmonary Embolism Testing Multicentre Study
An observational study of Pulmonary Embolism and D-dimer, run by Dr. Kerstin de Wit at 4 sites in Canada.
Trial summary
It is important to diagnose pulmonary embolism in a timely manner to prevent death and long-term disability. More than half a million people (4-5% of emergency department patients) are tested for pulmonary embolism, although the positive rate is low. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Pulmonary Embolism, D-dimer, Diagnosis
- What is being tested?
- Adjust-Unlikely
- How many people
- 4,000 participants
- Where
- 4 sitesCanada
- Study dates
- 1 Jan 2024to 30 Sep 2027
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Emergency department patient who is tested by an emergency physician for PE.
Who may be able to join
- Emergency department patient who is tested by an emergency physician for PE
Who cannot join
- Patient is < 18 years of age
- No documentation of whether PE is the most likely diagnosis
- D-dimer is not tested or else not resulted during the emergency visit
- The D-dimer level is known before documentation of whether PE is the most likely diagnosis
- The D-dimer is ordered prior to the physician assessing the patient
- The patient has previously registered that they opt out of all research at the participating site
Show all 15Show fewer
- The patient leaves against medical advice
- The patient has had PE or deep vein thrombosis imaging (CT pulmonary angiogram, ventilation-perfusion scan or lower limb ultrasound) within prior 30 days
- There is a new (non-PE) indication for anticoagulation
- The patient was initiated on treatment for presumed PE prior to PE testing
- The patient has previously been enrolled into the study
- The patient has a prior history of lower extremity deep vein thrombosis without availability of a baseline ultrasound scan
- The patient was transferred from another hospital organization
- The patient does not reside in Ontario
- The patient has no valid Ontario Health Insurance Plan card
Trial locations and contacts
4 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Canada4 sites, 2 recruiting
- Recruiting
Hamilton Health Sciences Corporation
Hamilton, Ontario, L8L 2X2
Natasha Clayton, 416-566-3590, claytonn@hhsc.ca
Alim Pardhan, MD
- Recruiting
Kingston Health Sciences Centre
Kingston, Ontario, K7L 2V7
Natasha Clayton, 416-566-3590, natasha.clayton@queensu.ca
Kerstin de Wit, MD
- Active, not recruiting
London Health Sciences Centre Research Inc
London, Ontario
- Active, not recruiting
Ottawa Hospital Research Institute
Ottawa, Ontario, K1Y 4E9
About this study
It is important to diagnose pulmonary embolism in a timely manner to prevent death and long-term disability. More than half a million people (4-5% of emergency department patients) are tested for pulmonary embolism, although the positive rate is low. Imaging for PE testing exposes patients to radiation, is expensive, adds time to the emergency visit, and can lead to a false positive diagnoses. Existing protocols aimed at reducing unnecessary pulmonary embolism imaging are complex and seldom used by emergency physicians. Too many patients undergo unnecessary pulmonary embolism imaging.
A new tool (called Adjust-Unlikely) could safely reduce pulmonary embolism imaging in Canada. A research group composed of researchers, emergency physicians, and patients developed the Adjust-Unlikely clinical decision rule: a rule which has been customized for emergency physicians and emergency patients. Adjust-Unlikely is highly sensitive at the bedside, meaning there are very few false negative results.
The study aim is to prospectively validate Adjust-Unlikely pulmonary embolism testing in emergency patients with suspected pulmonary embolism.
- Conditions
- Pulmonary Embolism, D-dimer, Diagnosis
- Being tested
- Adjust-Unlikely
- Keywords
- D-dimer, Pulmonary Embolism, Adjust-Unlikely, Diagnostic, Emergency Medicine
- Medical subject headings
- Pulmonary Embolism, Disease
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Adjust-UnlikelyDiagnostic test
Pulmonary embolism will be excluded during emergency department assessment by the combination of:
- 'Pulmonary embolism is the most likely diagnosis' as per the treating physician AND a D-dimer result < 500 ug/L fibrinogen equivalent units;
- 'Pulmonary embolism is not the most likely diagnosis' AND D-dimer < age-adjusted threshold; or,
- A negative computed tomography scan, planar ventilation perfusion scan or ventilation perfusion-SPECT.
Emergency departments will use their local laboratory D-dimer assay.
| Study group | Role | What they receive |
|---|---|---|
| Emergency department patients tested for pulmonary embolism. | Not described Receives: Diagnostic Test: Adjust-Unlikely |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of venous thrombosis events
Measured: 30 days
Secondary outcomes (2)
Number of venous thrombosis
Measured: 90 days
Index presentation Adjust-Unlikely testing results
Positive or negative 'Adjust-Unlikely' testing result
Measured: 90 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Mar 2024
- Study start1 Jan 2024
- Primary completion30 Sep 2026 (estimated)
- Study completion30 Sep 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Pulmonary EmbolismStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 4,000 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Dr. Kerstin de Wit
- Sponsor type
- University, hospital or other
- Collaborators
- Canadian Institutes of Health Research (CIHR)
- Responsible party
- Sponsor-investigator, Dr. Kerstin de Wit, Queen's University
- Investigators
- Kerstin de Wit, MD, Principal investigator, Queens University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06320236
- Sponsor's protocol ID
- 4603
- Acronym
- EMPET
- Status last verified
- Apr 2026
- First submitted
- 13 Mar 2024
- Last updated
- 20 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 20 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Emergency Medicine Pulmonary Embolism Testing Multicentre Study
- ClinicalTrials.gov ID
- NCT06320236
- Acronym / sponsor ID
- EMPET / 4603
- Conditions
- Pulmonary Embolism, D-dimer, Diagnosis
- Keywords
- D-dimer, Pulmonary Embolism, Adjust-Unlikely, Diagnostic, Emergency Medicine
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 4,000 participants (estimated)
- Lead sponsor
- Dr. Kerstin de WitUniversity, hospital or other
- Collaborators
- Canadian Institutes of Health Research (CIHR)
- Study start
- 1 Jan 2024 (actual)
- Primary completion
- 30 Sep 2026 (estimated)
- Study completion
- 30 Sep 2027 (estimated)
- First posted
- 20 Mar 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
It is important to diagnose pulmonary embolism in a timely manner to prevent death and long-term disability. More than half a million people (4-5% of emergency department patients) are tested for pulmonary embolism, although the positive rate is low. Imaging for PE testing exposes patients to radiation, is expensive, adds time to the emergency visit, and can lead to a false positive diagnoses. Existing protocols aimed at reducing unnecessary pulmonary embolism imaging are complex and seldom used by emergency physicians. Too many patients undergo unnecessary pulmonary embolism imaging.
A new tool (called Adjust-Unlikely) could safely reduce pulmonary embolism imaging in Canada. A research group composed of researchers, emergency physicians, and patients developed the Adjust-Unlikely clinical decision rule: a rule which has been customized for emergency physicians and emergency patients. Adjust-Unlikely is highly sensitive at the bedside, meaning there are very few false negative results.
The study aim is to prospectively validate Adjust-Unlikely pulmonary embolism testing in emergency patients with suspected pulmonary embolism.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Emergency department patients tested for pulmonary embolism. | – | Diagnostic Test: Adjust-Unlikely |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Emergency department patient who is tested by an emergency physician for PE.
Key inclusion criteria (1 listed)
- Emergency department patient who is tested by an emergency physician for PE
Key exclusion criteria (15 listed)
- Patient is < 18 years of age
- No documentation of whether PE is the most likely diagnosis
- D-dimer is not tested or else not resulted during the emergency visit
- The D-dimer level is known before documentation of whether PE is the most likely diagnosis
- The D-dimer is ordered prior to the physician assessing the patient
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Adjust-UnlikelyPulmonary embolism will be excluded during emergency department assessment by the combination of: 1. 'Pulmonary embolism is the most likely diagnosis' as per the treating physician AND a D-dimer result < 500 ug/L fibrinogen equivalent units; 2. 'Pulmonary embolism is not the most likely diagnosis' AND D-dimer < age-adjusted threshold; or, 3. A negative computed tomography scan, planar ventilation perfusion scan or ventilation perfusion-SPECT. Emergency departments will use their local laboratory D-dimer assay. | Diagnostic test | Emergency department patients tested for pulmonary embolism. |
Primary outcome
Number of venous thrombosis events
Time frame: 30 days
2 secondary outcomes
Number of venous thrombosis
Time frame: 90 days
Index presentation Adjust-Unlikely testing results
Time frame: 90 days
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Apr 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Kerstin de Wit, MD principal investigator
Queens University
4 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Pulmonary Embolism and D-dimer, run by Dr. Kerstin de Wit at 4 sites in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 15 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 20 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 4 sites in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Natasha S Clayton (416-566-3590, natasha.clayton@queensu.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of venous thrombosis events (time frame: 30 days). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 Apr 2026.