Emergency Medicine Pulmonary Embolism Testing Multicentre Study (EMPET)

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 Overview

• Status: Recruiting
• Conditions: Pulmonary Embolism; Diagnosis; D-dimer
• Intervention / Treatment: Diagnostic test: Adjust-Unlikely

• Study Type: Observational
• Enrollment (Estimated): 4000

Contacts and Locations

• Study Contact: Name: Natasha S Clayton; Phone Number: 416-566-3590; Email: natasha.clayton@queensu.ca

Study Locations

• Canada
  • Ontario
    • Hamilton, Ontario, Canada, L8L 2X2
      • Recruiting
      • Hamilton Health Sciences Corporation
      • Principal Investigator: Alim Pardhan, MD
      • Contact: Natasha Clayton; Phone Number: 416-566-3590; Email: claytonn@hhsc.ca
    • Kingston, Ontario, Canada, K7L 2V7
      • Recruiting
      • Kingston Health Sciences Centre
      • Principal Investigator: Kerstin de Wit, MD
      • Contact: Natasha Clayton; Phone Number: 416-566-3590; Email: natasha.clayton@queensu.ca
    • London, Ontario, Canada
      • Active, not recruiting
      • London Health Sciences Centre Research Inc
    • Ottawa, Ontario, Canada, K1Y 4E9
      • Active, not recruiting
      • Ottawa Hospital Research Institute

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Emergency department patient who is tested by an emergency physician for PE.

Description

Inclusion Criteria:

• Emergency department patient who is tested by an emergency physician for PE

Exclusion Criteria:

• 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
• 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

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Emergency department patients tested for pulmonary embolism.

Diagnostic test: Adjust-Unlikely; 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Number of venous thrombosis events	30 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Index presentation Adjust-Unlikely testing results	Positive or negative 'Adjust-Unlikely' testing result	90 days
Number of venous thrombosis		90 days

Collaborators and Investigators

• Sponsor: Dr. Kerstin de Wit
• Collaborators: Canadian Institutes of Health Research (CIHR)
• Investigators: Principal Investigator: Kerstin de Wit, MD, Queens University

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2024
• Primary Completion (Estimated): September 30, 2026
• Study Completion (Estimated): September 30, 2027

Study Registration Dates

• First Submitted: March 13, 2024
• First Submitted That Met QC Criteria: March 13, 2024
• First Posted (Actual): March 20, 2024

Study Record Updates

• Last Update Posted (Actual): April 20, 2026
• Last Update Submitted That Met QC Criteria: April 15, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Emergency Medicine; Diagnostic; D-dimer; Pulmonary Embolism; Adjust-Unlikely
• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Pathologic Processes; Respiratory Tract Diseases; Lung Diseases; Embolism and Thrombosis; Embolism; Pathological Conditions, Signs and Symptoms; Pulmonary Embolism; Disease
• Other Study ID Numbers: 4603

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No