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Validating 4Ts for Heparin Induced Thrombocytopenia (HIT)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00946400
Recruitment Status : Unknown
Verified July 2009 by Medstar Health Research Institute.
Recruitment status was:  Not yet recruiting
First Posted : July 27, 2009
Last Update Posted : July 27, 2009
Information provided by:
Medstar Health Research Institute

Brief Summary:
The purpose of this study is to evaluate a scoring tool to help determine the presence of Heparin Induced Thrombocytopenia (HIT), which is an adverse reaction to heparin. We hypothesize that this scoring tool will be very useful in excluding patients who are suspected of having HIT.

Condition or disease Intervention/treatment
Heparin-Induced Thrombocytopenia Other: Scoring 4Ts and Chong scale Other: Blood draw

Detailed Description:

HIT is an immune response to heparin that can result in thrombogenic thrombocytopenia. It is often a difficult diagnosis to make, and its diagnosis is dependent upon both clinical and serologic criteria. Due to this ambiguity, increased testing and treatment may occur until serologic test results return. Recently, scoring tools have been developed to assist with the diagnosis of this disease. However, these scoring tools have yet to be validated. Thus, we plan to conduct a prospective, observational study to validate two scoring tools, the 4Ts and the Chong scale, in the diagnosis of HIT.

In order to validate these scoring tools, two physicians will independently score the 4Ts and the Chong scale for all patients suspected of having HIT. These patients will be identified if a physician has ordered HIT antibody testing using the enzyme immunoassay (EIA) method. Confirmatory testing with a serotonin release assay (SRA) will also be performed.

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Study Type : Observational
Estimated Enrollment : 500 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: Prospectively Validating the 4Ts and Chong Score for Heparin Induced Thrombocytopenia
Study Start Date : August 2009

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Blood Thinners
Drug Information available for: Heparin

Group/Cohort Intervention/treatment
Suspected HIT
Those who are clinically suspected of having HIT will be enrolled in this study.
Other: Scoring 4Ts and Chong scale
Two physicians will independently score both the 4Ts and the Chong scale on all patients enrolled in this study.

Other: Blood draw
Patient serum will be collected to perform Serotonin Release Assay testing to verify the presence of HIT.

Primary Outcome Measures :
  1. To validate the 4Ts as a pretest probability tool for HIT. [ Time Frame: End of study. ]
  2. To validate the Chong scale as a tool to determine the post-test probability for HIT. [ Time Frame: End of study. ]

Secondary Outcome Measures :
  1. To determine the inter-rater variability for scoring the 4Ts. [ Time Frame: End of study. ]
  2. To determine the inter-rater variability for scoring the Chong scale. [ Time Frame: End of study. ]

Biospecimen Retention:   Samples Without DNA
Serum will be collected to perform a serotonin release assay as confirmatory testing for the presence of HIT.

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:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
For this study, patients already admitted to the hospital whose physician suspects the presence of HIT will be recruited for this study. Specifically, the trigger for recruitment include patients who have a HIT antibody test ordered.

Inclusion Criteria:

  • Patients with suspected HIT.

Exclusion Criteria:

  • None.

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 identifier (NCT number): NCT00946400

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Contact: Chee M Chan, MD (202) 877-7856

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United States, District of Columbia
Washington Hospital Center
Washington, District of Columbia, United States, 20010
Sub-Investigator: Andrew F Shorr, MD, MPH         
Sub-Investigator: Christian Woods, MD         
Sponsors and Collaborators
Medstar Health Research Institute
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Principal Investigator: Chee M Chan, MD Medstar Health Research Institute
Study Director: Andrew F Shorr, MD, MPH Medstar Health Research Institute
Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: George Sciortino, Medstar Research Institute Identifier: NCT00946400    
Other Study ID Numbers: 2009-202
First Posted: July 27, 2009    Key Record Dates
Last Update Posted: July 27, 2009
Last Verified: July 2009
Keywords provided by Medstar Health Research Institute:
Heparin-induced thrombocytopenia
Chong scale
interobserver variability
Additional relevant MeSH terms:
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Blood Platelet Disorders
Hematologic Diseases