Risk of Developing Antibodies to Heparin-PF4 After Heart Surgery (HIT)

February 22, 2013 updated by: Duke University

The Incidence of Thromboembolic Events in Patients With Antibodies to Heparin-PF4 After Cardiac Bypass

Heparin is a drug that is widely used to prevent and treat blood clotting. Individuals undergoing cardiopulmonary bypass surgery are administered high doses of heparin, and some of them develop antibodies to the drug. This immune response can lead to the formation of blood clots, setting the stage for a potential heart attack or stroke. The purpose of this study is to evaluate how often an immune response to heparin leads to the formation of blood clots in individuals who have had heart surgery.

Study Overview

Status

Completed

Conditions

Thrombosis

Intervention / Treatment

Drug: Heparin

Detailed Description

Heparin is a drug that is widely used to prevent and treat blood clotting. However, heparin can also cause serious adverse events. Individuals undergoing cardiopulmonary bypass surgery are administered and therefore exposed to high doses of heparin. Studies have shown that up to 61% of cardiac bypass patients develop elevated levels of antibodies to heparin-PF4 after surgery. This immune response may activate blood platelets, possibly resulting in a blood clot. These clots most often develop in the legs and lungs, and may lead to a heart attack or stroke. The frequency of such a reaction has yet to be determined definitively. This study will evaluate the incidence of an immune response to heparin-PF4 that leads to the formation of blood clots in individuals who have had heart surgery.

Participants in this study will be recruited prior to a scheduled cardiac bypass surgery. They will first complete a structured pre-operative interview to collect baseline measures on demographics, comorbidities, history of heparin exposures, and prior thromboembolic events. Immediately prior to surgery, a blood sample will be taken to assess the individual's platelet count and level of antibodies to heparin-PF4. Following the operation, participants will be followed daily to assess heparin exposure, platelet counts, and any blood clotting. Subsequent blood samples will be taken 5 days and 1 month following the surgery to again evaluate the individual's platelet count and level of heparin-PF4 antibodies. Additionally, participants will undergo a structured interview at 1 and 3 months post-surgery to evaluate the incidence of outcomes related to heparin-PF4 antibodies.

Study Type

Observational

Enrollment (Actual)

1015

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

United States
- Minnesota
  - Rochester, Minnesota, United States, 55905
    - Mayo Clinic, Rochester
- North Carolina
  - Chapel Hill, North Carolina, United States, 27599
    - University of North Carolina
  - Durham, North Carolina, United States, 27710
    - Duke University Medical Center
- Wisconsin
  - Madison, Wisconsin, United States, 53706
    - University of Wisconsin

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (ADULT, OLDER_ADULT)

Accepts Healthy Volunteers

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Individuals undergoing cardiac bypass surgery with heparin as the intra-operative anticoagulant at Duke University Hospital.

Description

Inclusion Criteria:

Scheduled for cardiac bypass surgery at Duke University Hospital

Exclusion Criteria:

Plans to receive warfarin during the post-operative inpatient stay
Plans to receive a full anticoagulant dose of low-molecular weight heparin during the post-operative inpatient stay
Plans to receive a full anticoagulant dose of unfractionated heparin during the post-operative inpatient stay
Use of any drug other than unfractionated heparin for anticoagulation during cardiopulmonary bypass
Warfarin, heparin, or low-molecular weight heparin administered during a readmission to the hospital for a reason other than one of this study's outcomes does not constitute criteria for exclusion

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Thrombotic events compatible with HIT Time Frame: one year	one year

Secondary Outcome Measures

Outcome Measure	Time Frame
antibody positibe status post operative day 5 and day 30 Time Frame: one year	one year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Duke University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

June 1, 2006

Primary Completion (ACTUAL)

March 1, 2009

Study Completion (ACTUAL)

July 1, 2012

Study Registration Dates

First Submitted

October 11, 2005

First Submitted That Met QC Criteria