Optimizing the Diagnosis of Heparin Induced Thrombocytopenia (HIT)

February 22, 2021 updated by: Ottawa Hospital Research Institute

Optimizing the Diagnosis of Heparin Induced Thrombocytopenia Using Quantified Anti-Platelet Factor 4 Immunological Testing: A Pilot Multicentre Cohort Study

Multicentre (Ottawa and Halifax) prospective cohort study using a diagnostic approach in patients clinically suspected to have HIT that combines pretest probability assessment with quantitative interpretation of anti-PF4 assay.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Unknown

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The proposed is a prospective cohort study exploring a novel diagnostic approach to Heparin Induced Thrombocytopenia (HIT) using a combination of pretest probability assessment and quantitative interpretation of the anti-platelet factor 4 Immunological assay (anti-PF4). Patient with a clinical suspicion of HIT will follow the study diagnostic algorithm (Figure 1). The study algorithm will be considered a safe approach to move forward into a larger RCT if the upper limit of the 95% confidence interval for 'false negative management failures' is ≤ 4% based on a Serotonin Release Assay (SRA) gold standard. The main objective of the pilot study is to inform feasibility and recruitment barriers for a larger randomized control trial.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Anticipated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
180

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: Chantal Rockwell, BA
  • Phone Number: 73958 613-737-8899
  • Email: crockwell@ohri.ca

Study Locations

  • Canada
    • Ontario
      • Ottawa, Ontario, Canada, KIH 8L6
        • Recruiting
        • The Ottawa Hospital
        • Contact:
        • Contact:
          • Lisa Duffett, MSc., MD
          • Phone Number: 71069 613-737-8899
          • Email: lduffett@toh.ca

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (ADULT, OLDER_ADULT)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Patient with clinical suspicion of HIT by treating physician

Exclusion Criteria:

  1. Less than 18 years of age;
  2. Prior diagnosis of HIT ever;
  3. Patient enrolled within preceding 100 days;
  4. Functional/ confirmatory platelet activation results available at the time of enrollment;
  5. Requiring cardio-pulmonary bypass or percutaneous cardiac angioplasty or any other cardiac or vascular surgery/procedure requiring intra-operative/procedural heparin administration planned within 30 days;
  6. Unable to complete study follow up;
  7. Unable to obtain consent (or proxy consent from substitute decision maker where applicable);
  8. Life expectancy less than 30 days;
  9. Greater than 72 hours from clinical suspicion of HIT and/or request for HIT anti-PF4 ELISA testing.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: DIAGNOSTIC
  • Allocation: NA
  • Interventional Model: SINGLE_GROUP
  • Masking: NONE

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
EXPERIMENTAL: diagnostic algorithm
Optimizing the interpretation of the more readily available anti-PF4 assay would reduce the reliance on functional testing/ confirmatory testing (Serotonin Release Assay, SRA) and the number of patients exposed to unnecessary changes in anticoagulation therapy while awaiting the timely functional test results
Diagnostic test: Diagnostic algorithm
The treating physician will complete an enrollment assessment including the 4T score pretest probability assessment14. All patients will have laboratory testing for HIT anti-PF4 as well as SRA testing. Results of the anti-PF4 assay (OD value) will be available to the treating physician who will be instructed to follow the study diagnostic algorithm

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Recruitment
Time Frame: 2 years
The pilot will be considered feasible if recruitment of at least 7.5 patients per month (total between the two sites) is achieved.
2 years
False negative management failures
Time Frame: 2 years
The rate of false negative 'management failures' where the study protocol concludes HIT unlikely but SRA (reference standard laboratory test) is positive for HIT (≥50% Serotonin release).
2 years

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Major arterial and venous thromboembolism events
Time Frame: 24 hours of baseline and 24 of study enrolment
Events will be ascertained from the date of study consent. However, venous or arterial thrombotic events detected on investigations ordered within 24 hours of study entry will be captured as baseline events and will be counted separately from thrombotic events which occur after the initial 24 hours of study enrolment.
24 hours of baseline and 24 of study enrolment
Proximal deep vein thrombosis
Time Frame: 2 years
Testing performed because of symptoms in a patient with (new) non-compressibility of the common femoral vein, popliteal vein or calf trifurcation vein of the leg on ultrasound; or new non-compressibility or visualization of thrombus in the jugular vein, subclavian vein or axillary vein on ultrasound; or an intraluminal defect seen in one more than one view in proximal leg or arm veins on venography will be diagnostic for deep vein thrombosis.
2 years
Pulmonary embolism
Time Frame: 2 years
Testing performed because of symptoms in a patient with a high probability lung scan (i.e. at least one segmental perfusion mismatch) or CT pulmonary angiography (i.e. intraluminal filling defect in the main, lobar or segmental pulmonary arteries) will be diagnostic for pulmonary embolism.
2 years
Stroke
Time Frame: 2 years
New infarction or hemorrhagic event confirmed on CT or MRI.
2 years
Myocardial infarction
Time Frame: 2 years
Detection of rise and/or fall of cardiac biomarkers (preferably troponin) with at least one value above the 99th percentile of the upper reference limit together with evidence of myocardial ischemia with at least one of the following: Symptoms of ischemia for ≥ 20 minutes ECG changes indicative of new ischemia: new ST-T changes ≥0.1 mV or new left bundle branch block Development of pathological Q waves in the ECG; Imaging evidence of new loss of viable myocardium or new regional wall motion abnormality.
2 years
Systemic arterial embolism
Time Frame: 2 years
Acute vascular occlusion confirmed on ultrasound or angiography Adrenal hemorrhagic infarction (indicating adrenal vein thrombosis) - radiologic diagnosis on ultrasound or CT.
2 years
Death
Time Frame: 30 days of follow up
Due to major arterial or venous thromboembolism within 30days of follow up and major and minor bleeding.
30 days of follow up

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Ottawa Hospital Research Institute

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Lisa Duffett, MSc, MD, Ottawa Hospital Research Institute

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (ACTUAL)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 23, 2018

Primary Completion (ANTICIPATED)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 1, 2021

Study Completion (ANTICIPATED)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 1, 2022

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
April 10, 2017

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 8, 2017

First Posted (ACTUAL)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
May 11, 2017

Study Record Updates

Last Update Posted (ACTUAL)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
February 24, 2021

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 22, 2021

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
February 1, 2021

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • IRIS6428

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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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