Heparin Induced ThrombocytopeniaHIT-RADIONCT01178333
Heparin-Induced Thrombocytopenia - Retrospective Analysis of Data on Incidence and Outcomes Study
An observational study of Heparin Induced Thrombocytopenia, run by Carelon Research at 21 sites in United States.
Trial summary
HIT-RADIO is a study of patients who had a positive heparin PF-4 antibody test between 1/21/2008 and 9/25/2008 at selected hospitals. The study will collect and analyse information that is already in the patients' medical records. Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Heparin Induced Thrombocytopenia
- How many people
- 668 participants
- Where
- 21 sitesUnited States
- Study dates
- Jun 2010to Dec 2010
- Phase
- Observational
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Any age
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Study population: Subjects with a positive heparin PF-4 antibody test drawn between 1/21/2008 and 9/25/2008
Who may be able to join
- All subjects with a positive heparin PF-4 antibody test occurring between 1/21/2008 and 9/25/2008
- Medical record available for the admission during which the positive heparin PF-4 antibody test was obtained
Who cannot join
- None
Trial locations and contacts
21 sites in 1 country.
21 sites in 1 country
United States21 sites
University of Maryland Greenebaum Cancer Center
Baltimore, Maryland, 21201
Johns Hopkins
Baltimore, Maryland, 21205
Massachusetts General Hospital
Boston, Massachusetts, 02114
Brigham and Women's Hospital
Boston, Massachusetts, 02115
Children's Hospital, Boston
Boston, Massachusetts, 02115
Beth Israel Deaconess Medical Center
Boston, Massachusetts, 02215
University of North Carolina, Chapel Hill
Chapel Hill, North Carolina, 27599
Case Western Reserve University School of Medicine
Cleveland, Ohio, 44106
Cleveland Clinic
Cleveland, Ohio, 44195
Duke University Medical Center
Durham, North Carolina, 27710
University of Iowa
Iowa City, Iowa, 52242
Gunderson Clinic
La Crosse, Wisconsin, 54601
University of Wisconsin Comprehensive Cancer Center
Madison, Wisconsin, 53792
Froedtert
Milwaukee, Wisconsin, 53201
St. Luke's Medical Center
Milwaukee, Wisconsin, 53215
University of Minnesota
Minneapolis, Minnesota, 55455
Tulane University
New Orleans, Louisiana, 70112
Cornell University
New York, New York, 10065
University of Pennsylvania
Philadelphia, Pennsylvania, 19104
University of Pittsburgh
Pittsburgh, Pennsylvania, 15213
Fred Hutchinson Cancer Research Center
Seattle, Washington, 98104
About this study
Official title: Heparin-Induced Thrombocytopenia - Retrospective Analysis of Data on Incidence and Outcomes Study (HIT-RADIO Study)
HIT-RADIO is a study of patients who had a positive heparin PF-4 antibody test between 1/21/2008 and 9/25/2008 at selected hospitals. The study will collect and analyse information that is already in the patients' medical records. Information about laboratory values (such as platelet counts), treatments (such as medications), and outcomes (such as blood clots, amputation, and death) will be included.
Read the detailed description
HIT-RADIO is a retrospective chart-review study of patients who had a positive heparin PF-4 antibody test between 1/21/2008 and 9/25/2008 at selected hospitals associated with the Transfusion Medicine/Hemostasis Clinical Trials Network .
Heparin-induced thrombocytopenia (HIT) is a major complication of the administration of heparin and can result in life-threatening thrombosis with or without thrombocytopenia (HIT-T) or can produce thrombocytopenia without clinically symptomatic thrombosis ("isolated" HIT). Isolated heparin-induced thrombocytopenia is defined as a fall in platelet count associated with a positive heparin PF-4 antibody test, in the absence of clinically overt thrombosis. While the treatment of HIT-T (HIT with thrombosis) with anticoagulation is well established, the risks and treatment of isolated HIT are unclear.
It is anticipated that this data analysis will provide a current overview of the implications of a positive heparin PF-4 antibody test in clinical practice. It should determine the percentage of positive heparin PF-4 antibody tests that are associated with thrombocytopenia and thrombosis (HIT-T) or "isolated" HIT at diagnosis and the subsequent major clinical outcomes of death, limb amputation/gangrene, and new thrombosis. No "snapshot" of such HIT patients has been conducted in the past decade and the results will be important in assessing the impact of HIT in current medical care as well as documenting current treatment strategies.
- Conditions
- Heparin Induced Thrombocytopenia
- Keywords
- Thrombocytopenia, Heparin
- Medical subject headings
- Thrombocytopenia
What is being measured
The primary outcome is the main question the study is designed to answer.
Time to Occurrence of a Composite Triple Endpoint Consisting of Death, Limb Amputation/Gangrene, and New Thrombosis
The mean time to an event is estimated by the area under the survival function. If the largest time is an event time, then the survival function goes to zero at that time, and the mean survival estimate is finite. Otherwise, the mean time cannot be estimated and may lead to a bias.
Measured: From the time that the positive heparin PF-4 antibody test was drawn until hospital discharge or day 45, whichever occurred first.
Time to Occurrence of a Composite Triple Endpoint Consisting of Death, Limb Amputation/Gangrene, and New Thrombosis
The median survival time is reported by each group for the time to occurrence of a composite triple endpoint consisting of death, limb amputation/gangrene, and new thrombosis.
Measured: From the time that the positive heparin PF-4 antibody test was drawn until hospital discharge or day 45, whichever occurred first.
Secondary outcomes (15)
Time to Death
The mean time to an event is estimated by the area under the survival function. If the largest time is an event time, then the survival function goes to zero at that time, and the mean survival estimate is finite. Otherwise, the mean time cannot be estimated and may lead to a bias.
Measured: From the time the positive heparin PF-4 antibody test was drawn until hospital discharge, death, or day 45, whichever occurred first
Time to Death
The median survival time is reported by each group for the time to death.
Measured: From the time the positive heparin PF-4 antibody test was drawn until hospital discharge, death, or day 45, whichever occurred first
Time to Occurrence of Limb Amputation or Limb Gangrene
Due to the small number of events, the median or mean survival time could not be defined. Therefore, the number of subjects with limb amputation or limb gangrene was reported in "Outcome Measure Data Table".
Measured: From the time the positive heparin PF-4 antibody test was drawn until hospital discharge, death, or day 45, whichever occurred first
Time to Occurrence of Radiographically Confirmed Thromboembolism
The mean time to an event is estimated by the area under the survival function. If the largest time is an event time, then the survival function goes to zero at that time, and the mean survival estimate is finite. Otherwise, the mean time cannot be estimated and may lead to a bias. However, the median survival times could not be defined for all three groups, so the mean time was reported in "Outcome Measure Data Table".
Measured: From the time the positive heparin PF-4 antibody test was drawn until hospital discharge, death, or day 45, whichever occurred first
Time to Occurrence of Major Bleeding
The mean time to an event is estimated by the area under the survival function. If the largest time is an event time, then the survival function goes to zero at that time, and the mean survival estimate is finite. Otherwise, the mean time cannot be estimated and may lead to a bias.
Measured: From the time that the positive heparin PF-4 antibody test was drawn until hospital discharge, death, or day 45, whichever occurred first
Time to Occurrence of Major Bleeding
The median survival time is reported by each group for the time to occurrence of major bleeding.
Measured: From the time that the positive heparin PF-4 antibody test was drawn until hospital discharge, death, or day 45, whichever occurred first
Proportion of Subjects With HIT With Thrombosis (HIT-T) and Isolated HIT
Proportion of subjects who, at the time the positive heparin PF-4 antibody test was drawn, were in each of the following categories:
- Group 1: Those with thrombosis and or without thrombocytopenia (HIT-T): 16% of 442 subjects.
- Group 2: Those with thrombocytopenia but not thrombosis (Isolated HIT): 64% of 442 subjects.
- Group 3: Those with neither thrombocytopenia nor thrombosis (Neither HIT-T nor Isolated HIT): 20% of 442 subjects.
Measured: From the date 5 days before the positive heparin PF-4 antibody test was drawn to the date it was drawn
Type of Heparin Exposure - Unfractionated Heparin (UFH)
Two types of heparins are commonly used as anticoagulants - unfractionated heparin (UFH) and low-molecular-weight heparin (LMWH). UFH has been used for the prevention and treatment of thrombosis for several decades.
Measured: Hospital admission to date the positive heparin PF-4 antibody test was drawn, or 28 days prior to the date it was drawn, whichever is later, through the date it was drawn
Type of Heparin Exposure - Low Molecular Weight Heparin (LMWH)
Two types of heparins are commonly used as anticoagulants - unfractionated heparin (UFH) and low-molecular-weight heparin (LMWH). LMWHs are derived from UFH by depolymerization. Each LMWH product has a specific molecular weight distribution that determines its anticoagulant activity and duration of action.
Measured: Hospital admission to date the positive heparin PF-4 antibody test was drawn, or 28 days prior to the date it was drawn, whichever is later, through the date it was drawn
Relationship of the Heparin PF-4 (Platelet Factor 4) Antibody Titer to the Clinical Diagnosis
Heparin PF-4 (platelet factor 4) optical density (OD) test results were the dichotomous outcome (<1.0 vs. >=1.0). Clinical diagnosis was three groups (HIT-T, Isolated HIT and No HIT). The Heparin PF-4 optical density test looks for antibodies to complexes of heparin combined with platelet factor 4. Higher optical density indicates higher antibody concentration. We could say that generally OD values above 0.4 are considered a positive result, and that the higher the OD, the greater the concentration of antibodies in the patient's blood.
Measured: From the time the positive heparin PF-4 antibody test was drawn until hospital discharge, death, or day 45, whichever occurred first
Relationship of the Heparin PF-4 Antibody Titer to the Degree of Thrombocytopenia
Heparin PF-4 optical density (OD) test results were the dichotomous outcome (<1.0 vs. >=1.0). Nadir Platelet Count (x10^9 / L) was used for the degree of thrombocytopenia. The Heparin PF-4 optical density test looks for antibodies to complexes of heparin combined with platelet factor 4. Higher optical density indicates higher antibody concentration. We could say that generally OD values above 0.4 are considered a positive result, and that the higher the OD, the greater the concentration of antibodies in the patient's blood.
Measured: From the time the positive heparin PF-4 antibody test was drawn until hospital discharge, death, or day 45, whichever occurred first
Relationship of the Heparin PF-4 Antibody Titer to the Primary Endpoint
Heparin PF-4 OD test results were the dichotomous outcome (<1.0 vs. >=1.0). Primary endpoint was the composite endpoint of death, limb amputation/gangrene, or new thrombosis.
Measured: From the time the positive heparin PF-4 antibody test was drawn until hospital discharge, death, or day 45, whichever occurred first
Use of Treatment (Non-heparin Anticoagulant) Used in Hospital
Types of treatment (direct thrombin inhibitor, fondaparinux, warfarin, no treatment) provided to subjects in hospital
Measured: From the time that the positive heparin PF-4 antibody test was drawn until hospital discharge, death, or day 45, whichever occurred first
Use of Treatment (Non-heparin Anticoagulant) Used at the Time of Discharge
Measured: From the time that the positive heparin PF-4 antibody test was drawn until hospital discharge, death, or day 45, whichever occurred first
Time to Platelet Recovery, Among Subjects With a Low Platelet Count When the Positive PF4 Antibody Test Was Drawn
Measured: From the time that the nadir platelet count was drawn until hospital discharge, death, or day 45, whichever occurred first
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Aug 2010 (estimated)
- Study startJun 2010
- Primary completionDec 2010
- Study completionDec 2010
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Heparin Induced ThrombocytopeniaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case only
- Time perspective
- Retrospective
- Enrolment
- 668 participants (actual)
Sponsor and investigators
- Lead sponsor
- Carelon Research
- Sponsor type
- University, hospital or other
- Collaborators
- National Heart, Lung, and Blood Institute (NHLBI)
- Responsible party
- Sponsor
- Investigators
- Susan F Assmann, PhD, Principal investigator, Carelon ResearchDavid Kuter, MD, Principal investigator, Massachusetts General HospitalEliot Williams, MD PHD, Principal investigator, University of Wisconsin, MadisonKenneth Friedman, MD, Principal investigator, Versiti Blood HealthRonald Go, MD, Principal investigator, Gunderson ClinicKeith McCrae, MD, Principal investigator, The Cleveland ClinicEllis Neufeld, MD PHD, Principal investigator, Boston Children's HospitalLynne Uhl, MD, Principal investigator, Beth Israel Deaconess Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01178333
- Sponsor's protocol ID
- 678
- Other IDs
- U01HL072268
- Acronym
- HIT-RADIO
- Status last verified
- Mar 2013
- First submitted
- 6 Aug 2010
- Last updated
- 22 May 2015
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 22 May 2015. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Heparin-Induced Thrombocytopenia - Retrospective Analysis of Data on Incidence and Outcomes Study (HIT-RADIO Study)
- ClinicalTrials.gov ID
- NCT01178333
- Acronym / sponsor ID
- HIT-RADIO / 678
- Conditions
- Heparin Induced Thrombocytopenia
- Keywords
- Thrombocytopenia, Heparin
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 668 participants (actual)
- Lead sponsor
- Carelon ResearchUniversity, hospital or other
- Collaborators
- National Heart, Lung, and Blood Institute (NHLBI)
- Study start
- Jun 2010
- Primary completion
- Dec 2010 (actual)
- Study completion
- Dec 2010 (actual)
- First posted
- 10 Aug 2010 (estimated)
- Results
- Posted 4 May 2015
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
HIT-RADIO is a study of patients who had a positive heparin PF-4 antibody test between 1/21/2008 and 9/25/2008 at selected hospitals. The study will collect and analyse information that is already in the patients' medical records. Information about laboratory values (such as platelet counts), treatments (such as medications), and outcomes (such as blood clots, amputation, and death) will be included.
Detailed description
HIT-RADIO is a retrospective chart-review study of patients who had a positive heparin PF-4 antibody test between 1/21/2008 and 9/25/2008 at selected hospitals associated with the Transfusion Medicine/Hemostasis Clinical Trials Network .
Heparin-induced thrombocytopenia (HIT) is a major complication of the administration of heparin and can result in life-threatening thrombosis with or without thrombocytopenia (HIT-T) or can produce thrombocytopenia without clinically symptomatic thrombosis ("isolated" HIT). Isolated heparin-induced thrombocytopenia is defined as a fall in platelet count associated with a positive heparin PF-4 antibody test, in the absence of clinically overt thrombosis. While the treatment of HIT-T (HIT with thrombosis) with anticoagulation is well established, the risks and treatment of isolated HIT are unclear.
It is anticipated that this data analysis will provide a current overview of the implications of a positive heparin PF-4 antibody test in clinical practice. It should determine the percentage of positive heparin PF-4 antibody tests that are associated with thrombocytopenia and thrombosis (HIT-T) or "isolated" HIT at diagnosis and the subsequent major clinical outcomes of death, limb amputation/gangrene, and new thrombosis. No "snapshot" of such HIT patients has been conducted in the past decade and the results will be important in assessing the impact of HIT in current medical care as well as documenting current treatment strategies.
Study design
- Observational model
- Case only
- Time perspective
- Retrospective
Who may qualify
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- Study population
- Subjects with a positive heparin PF-4 antibody test drawn between 1/21/2008 and 9/25/2008
Key inclusion criteria (2 listed)
- All subjects with a positive heparin PF-4 antibody test occurring between 1/21/2008 and 9/25/2008
- Medical record available for the admission during which the positive heparin PF-4 antibody test was obtained
Key exclusion criteria (1 listed)
- None
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Time to Occurrence of a Composite Triple Endpoint Consisting of Death, Limb Amputation/Gangrene, and New Thrombosis
Time frame: From the time that the positive heparin PF-4 antibody test was drawn until hospital discharge or day 45, whichever occurred first.
The mean time to an event is estimated by the area under the survival function. If the largest time is an event time, then the survival function goes to zero at that time, and the mean survival estimate is finite. Otherwise, the mean time cannot be estimated and may lead to a bias.
Time to Occurrence of a Composite Triple Endpoint Consisting of Death, Limb Amputation/Gangrene, and New Thrombosis
Time frame: From the time that the positive heparin PF-4 antibody test was drawn until hospital discharge or day 45, whichever occurred first.
The median survival time is reported by each group for the time to occurrence of a composite triple endpoint consisting of death, limb amputation/gangrene, and new thrombosis.
15 secondary outcomes
Time to Death
Time frame: From the time the positive heparin PF-4 antibody test was drawn until hospital discharge, death, or day 45, whichever occurred first
Time to Death
Time frame: From the time the positive heparin PF-4 antibody test was drawn until hospital discharge, death, or day 45, whichever occurred first
Time to Occurrence of Limb Amputation or Limb Gangrene
Time frame: From the time the positive heparin PF-4 antibody test was drawn until hospital discharge, death, or day 45, whichever occurred first
Time to Occurrence of Radiographically Confirmed Thromboembolism
Time frame: From the time the positive heparin PF-4 antibody test was drawn until hospital discharge, death, or day 45, whichever occurred first
Time to Occurrence of Major Bleeding
Time frame: From the time that the positive heparin PF-4 antibody test was drawn until hospital discharge, death, or day 45, whichever occurred first
Time to Occurrence of Major Bleeding
Time frame: From the time that the positive heparin PF-4 antibody test was drawn until hospital discharge, death, or day 45, whichever occurred first
Proportion of Subjects With HIT With Thrombosis (HIT-T) and Isolated HIT
Time frame: From the date 5 days before the positive heparin PF-4 antibody test was drawn to the date it was drawn
Type of Heparin Exposure - Unfractionated Heparin (UFH)
Time frame: Hospital admission to date the positive heparin PF-4 antibody test was drawn, or 28 days prior to the date it was drawn, whichever is later, through the date it was drawn
Type of Heparin Exposure - Low Molecular Weight Heparin (LMWH)
Time frame: Hospital admission to date the positive heparin PF-4 antibody test was drawn, or 28 days prior to the date it was drawn, whichever is later, through the date it was drawn
Relationship of the Heparin PF-4 (Platelet Factor 4) Antibody Titer to the Clinical Diagnosis
Time frame: From the time the positive heparin PF-4 antibody test was drawn until hospital discharge, death, or day 45, whichever occurred first
Relationship of the Heparin PF-4 Antibody Titer to the Degree of Thrombocytopenia
Time frame: From the time the positive heparin PF-4 antibody test was drawn until hospital discharge, death, or day 45, whichever occurred first
Relationship of the Heparin PF-4 Antibody Titer to the Primary Endpoint
Time frame: From the time the positive heparin PF-4 antibody test was drawn until hospital discharge, death, or day 45, whichever occurred first
Use of Treatment (Non-heparin Anticoagulant) Used in Hospital
Time frame: From the time that the positive heparin PF-4 antibody test was drawn until hospital discharge, death, or day 45, whichever occurred first
Use of Treatment (Non-heparin Anticoagulant) Used at the Time of Discharge
Time frame: From the time that the positive heparin PF-4 antibody test was drawn until hospital discharge, death, or day 45, whichever occurred first
Time to Platelet Recovery, Among Subjects With a Low Platelet Count When the Positive PF4 Antibody Test Was Drawn
Time frame: From the time that the nadir platelet count was drawn until hospital discharge, death, or day 45, whichever occurred first
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 May 2015.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Susan F Assmann, PhD principal investigator
Carelon Research
David Kuter, MD principal investigator
Massachusetts General Hospital
Eliot Williams, MD PHD principal investigator
University of Wisconsin, Madison
21 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Heparin Induced Thrombocytopenia, run by Carelon Research at 21 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 22 May 2015. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 21 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Yes. Results are posted in the registry (first posted 4 May 2015). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Time to Occurrence of a Composite Triple Endpoint Consisting of Death, Limb Amputation/Gangrene, and New Thrombosis (time frame: From the time that the positive heparin PF-4 antibody test was drawn until hospital discharge or day 45, whichever occurred first.). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 May 2015.