Heparin-Induced Thrombocytopenia - Retrospective Analysis of Data on Incidence and Outcomes Study (HIT-RADIO)

This study has been completed.
Sponsor:
Collaborator:
Information provided by (Responsible Party):
New England Research Institutes
ClinicalTrials.gov Identifier:
NCT01178333
First received: August 6, 2010
Last updated: May 6, 2015
Last verified: March 2013
  Purpose

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.


Condition
Heparin Induced Thrombocytopenia

Study Type: Observational
Study Design: Observational Model: Case-Only
Time Perspective: Retrospective
Official Title: Heparin-Induced Thrombocytopenia - Retrospective Analysis of Data on Incidence and Outcomes Study (HIT-RADIO Study)

Resource links provided by NLM:


Further study details as provided by New England Research Institutes:

Primary Outcome Measures:
  • 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. ] [ Designated as safety issue: No ]
    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. ] [ Designated as safety issue: No ]
    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.


Secondary Outcome Measures:
  • 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 ] [ Designated as safety issue: No ]
    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 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 ] [ Designated as safety issue: No ]
    The median survival time is reported by each group for the time to death.

  • 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 ] [ Designated as safety issue: No ]
    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".

  • 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 ] [ Designated as safety issue: No ]
    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".

  • 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 ] [ Designated as safety issue: No ]
    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 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 ] [ Designated as safety issue: No ]
    The median survival time is reported by each group for the time to occurrence of major bleeding.

  • 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 ] [ Designated as safety issue: No ]

    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.

  • 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 ] [ Designated as safety issue: No ]
    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.

  • 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 ] [ Designated as safety issue: No ]
    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.

  • 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 ] [ Designated as safety issue: No ]
    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.

  • 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 ] [ Designated as safety issue: No ]
    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.

  • 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 ] [ Designated as safety issue: No ]
    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.

  • 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 ] [ Designated as safety issue: No ]
    Types of treatment (direct thrombin inhibitor, fondaparinux, warfarin, no treatment) provided to subjects in hospital

  • 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 ] [ Designated as safety issue: No ]
  • 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 ] [ Designated as safety issue: No ]

Enrollment: 668
Study Start Date: June 2010
Study Completion Date: December 2010
Primary Completion Date: December 2010 (Final data collection date for primary outcome measure)
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.

  Eligibility

Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population

Subjects with a positive heparin PF-4 antibody test drawn between 1/21/2008 and 9/25/2008

Criteria

Inclusion Criteria:

  • 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

Exclusion Criteria:

  • None
  Contacts and Locations
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, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01178333

Locations
United States, Iowa
University of Iowa
Iowa City, Iowa, United States, 52242
United States, Louisiana
Tulane University
New Orleans, Louisiana, United States, 70112
United States, Maryland
Johns Hopkins
Baltimore, Maryland, United States, 21205
University of Maryland Greenebaum Cancer Center
Baltimore, Maryland, United States, 21201
United States, Massachusetts
Beth Israel Deaconess Medical Center
Boston, Massachusetts, United States, 02215
Brigham and Women's Hospital
Boston, Massachusetts, United States, 02115
Children's Hospital, Boston
Boston, Massachusetts, United States, 02115
Massachusetts General Hospital
Boston, Massachusetts, United States, 02114
United States, Minnesota
University of Minnesota
Minneapolis, Minnesota, United States, 55455
United States, New York
Cornell University
New York, New York, United States, 10065
United States, North Carolina
University of North Carolina, Chapel Hill
Chapel Hill, North Carolina, United States, 27599
Duke University Medical Center
Durham, North Carolina, United States, 27710
United States, Ohio
Case Western Reserve University School of Medicine
Cleveland, Ohio, United States, 44106
Cleveland Clinic
Cleveland, Ohio, United States, 44195
United States, Pennsylvania
University of Pennsylvania
Philadelphia, Pennsylvania, United States, 19104
University of Pittsburgh
Pittsburgh, Pennsylvania, United States, 15213
United States, Washington
Fred Hutchinson Cancer Research Center
Seattle, Washington, United States, 98104
United States, Wisconsin
Gunderson Clinic
LaCrosse, Wisconsin, United States, 54601
University of Wisconsin Comprehensive Cancer Center
Madison, Wisconsin, United States, 53792
Froedtert
Milwaukee, Wisconsin, United States, 53201
St. Luke's Medical Center
Milwaukee, Wisconsin, United States, 53215
Sponsors and Collaborators
New England Research Institutes
Investigators
Principal Investigator: Susan F Assmann, PhD New England Research Institutes
Principal Investigator: David Kuter, MD Massachusetts General Hospital
Principal Investigator: Eliot Williams, MD PHD University of Wisconsin, Madison
Principal Investigator: Kenneth Friedman, MD Blood Center of Wisconsin
Principal Investigator: Ronald Go, MD Gunderson Clinic
Principal Investigator: Keith McCrae, MD The Cleveland Clinic
Principal Investigator: Ellis Neufeld, MD PHD Children's Hospital Boston
Principal Investigator: Lynne Uhl, MD Beth Israel Deaconess Medical Center
Principal Investigator: Judith Lin, MD Brigham and Women's Hospital
Principal Investigator: James Bussel, MD Cornell University
Principal Investigator: Thomas Ortel, MD PHD Duke University
Principal Investigator: Jodi Segal, MD MPH Johns Hopkins University
Principal Investigator: Barbara Konkle, MD Puget Sound Blood Center
Principal Investigator: Cindy Leissinger, MD Tulane University
Principal Investigator: Thomas Raife, MD University of Iowa
Principal Investigator: Ann Zimrin, MD University of Maryland Greenebaum Cancer Center
Principal Investigator: Jeffrey McCullough, MD University of Minnesota - Clinical and Translational Science Institute
Principal Investigator: Nigel Key, MD University of North Carolina, Chapel Hill
Principal Investigator: Bruce Sachais, MD PHD University of Pennsylvania
Principal Investigator: Joseph Kiss, MD University of Pittsburgh Institute for Transfusion Medicine
  More Information

No publications provided

Responsible Party: New England Research Institutes
ClinicalTrials.gov Identifier: NCT01178333     History of Changes
Other Study ID Numbers: 678, U01HL072268
Study First Received: August 6, 2010
Results First Received: March 17, 2015
Last Updated: May 6, 2015
Health Authority: United States: Federal Government

Keywords provided by New England Research Institutes:
Thrombocytopenia
Heparin

Additional relevant MeSH terms:
Thrombocytopenia
Blood Platelet Disorders
Hematologic Diseases

ClinicalTrials.gov processed this record on August 30, 2015