Validating 4Ts for Heparin Induced Thrombocytopenia (HIT)

Prospectively Validating the 4Ts and Chong Score for Heparin Induced Thrombocytopenia

Status

UNKNOWN

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT00946400

Enrollment

500

Registered

2009-07-27

Start date

2009-08-31

Completion date

Unknown

Last updated

2009-07-27

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Heparin-Induced Thrombocytopenia

Keywords

Heparin-induced thrombocytopenia, HIT, 4Ts, Chong scale, interobserver variability

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.

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.

Interventions

OTHERScoring 4Ts and Chong scale

Two physicians will independently score both the 4Ts and the Chong scale on all patients enrolled in this study.

OTHERBlood draw

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

Study design

Observational model

COHORT

Time perspective

PROSPECTIVE

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Inclusion criteria

* Patients with suspected HIT.

Exclusion criteria

* None.

Design outcomes

Primary

Measure	Time frame
To validate the 4Ts as a pretest probability tool for HIT.	End of study.
To validate the Chong scale as a tool to determine the post-test probability for HIT.	End of study.

Secondary

Measure	Time frame
To determine the inter-rater variability for scoring the 4Ts.	End of study.
To determine the inter-rater variability for scoring the Chong scale.	End of study.

Countries

United States

Contacts

Primary ContactChee M Chan, MD

chee.m.chan@medstar.net(202) 877-7856

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 17, 2026