Validating 4Ts for Heparin Induced Thrombocytopenia (HIT)

The recruitment status of this study is unknown because the information has not been verified recently.
Verified July 2009 by Washington Hospital Center.
Recruitment status was  Not yet recruiting
Information provided by:
Washington Hospital Center Identifier:
First received: July 24, 2009
Last updated: NA
Last verified: July 2009
History: No changes posted

July 24, 2009
July 24, 2009
August 2009
Not Provided
  • To validate the 4Ts as a pretest probability tool for HIT. [ Time Frame: End of study. ] [ Designated as safety issue: No ]
  • To validate the Chong scale as a tool to determine the post-test probability for HIT. [ Time Frame: End of study. ] [ Designated as safety issue: No ]
Same as current
No Changes Posted
  • To determine the inter-rater variability for scoring the 4Ts. [ Time Frame: End of study. ] [ Designated as safety issue: No ]
  • To determine the inter-rater variability for scoring the Chong scale. [ Time Frame: End of study. ] [ Designated as safety issue: No ]
Same as current
Not Provided
Not Provided
Validating 4Ts for Heparin Induced Thrombocytopenia (HIT)
Prospectively Validating the 4Ts and Chong Score for Heparin Induced Thrombocytopenia
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.

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.

Observational Model: Cohort
Time Perspective: Prospective
Not Provided
Retention:   Samples Without DNA
Serum will be collected to perform a serotonin release assay as confirmatory testing for the presence of HIT.
Non-Probability Sample
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.
Heparin-Induced Thrombocytopenia
  • 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.
Suspected HIT
Those who are clinically suspected of having HIT will be enrolled in this study.
  • Other: Scoring 4Ts and Chong scale
  • Other: Blood draw

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
Not yet recruiting
Not Provided
Not Provided

Inclusion Criteria:

  • Patients with suspected HIT.

Exclusion Criteria:

18 Years and older
Contact: Chee M Chan, MD (202) 877-7856
United States
George Sciortino, Medstar Research Institute
Washington Hospital Center
Principal Investigator: Chee M Chan, MD Washington Hospital Center
Study Director: Andrew F Shorr, MD, MPH Washington Hospital Center
Washington Hospital Center
July 2009

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP