Response of Recombinant Antithrombin in Heparin Resistant Patients Undergoing Cardiac Surgery

This study has suspended participant recruitment.
(Changes in protocol)
Sponsor:
Collaborator:
rEVO Biologics
Information provided by (Responsible Party):
William C. Oliver, Mayo Clinic
ClinicalTrials.gov Identifier:
NCT01547728
First received: February 7, 2012
Last updated: December 20, 2013
Last verified: December 2013
  Purpose

The objective of this study is to prospectively evaluate the response of recombinant antithrombin (rAT) (ATRYN) in patients who are heparin resistant and are scheduled to undergo cardiac surgery.


Condition Intervention Phase
Heparin Resistance
Drug: ATryn ® ( recombinant antithrombin, rhAT)
Phase 4

Study Type: Interventional
Study Design: Endpoint Classification: Safety/Efficacy Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Response of Recombinant Antithrombin in Heparin Resistant Patients Undergoing Cardiac Surgery

Resource links provided by NLM:


Further study details as provided by Mayo Clinic:

Primary Outcome Measures:
  • Percentage of patients whose activated clotting time (ACT) is prolonged beyond 480 seconds with recombinant human antithrombin concentrate (rhAT) administration [ Time Frame: 3 minutes after the initial dose of rhAT, Day 1 of the study ] [ Designated as safety issue: No ]
    Restored antithrombin level is defined as an activated clotting time > 480 seconds 3 minutes after the initial dose of 500 units of rhAT is administered. The percentage of patients who meet this criterion will be summarized using a point estimate and a 95% confidence interval.


Secondary Outcome Measures:
  • Percentage of cardiopulmonary bypass patients who are heparin resistant [ Time Frame: 5 minutes after intravenous loading dose of heparin, Day 1 of the study ] [ Designated as safety issue: Yes ]
    Patient will be identified as heparin resistant according this definition: initial activated clotting time (ACT) after intravenous loading dose of heparin (300 u/kg) is less than 480 seconds. The percentage will be summarized using a point estimate and 95% confidence interval.


Estimated Enrollment: 60
Study Start Date: February 2012
Estimated Study Completion Date: February 2015
Estimated Primary Completion Date: February 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: ATryn ® (recombinant antithrombin, rhAT)
Assessing the prolongation of the activated clotting time after administration of ATryn® (recombinant antithrombin, rhAT)in heparin resistant patients. Subjects will be enrolled if they exhibit heparin resistance as defined by protocol after an intravenous loading dose of heparin just prior to cardiopulmonary bypass.
Drug: ATryn ® ( recombinant antithrombin, rhAT)
This study evaluates whether ATryn® (recombinant antithrombin,rhAT) will improve heparin responsiveness of heparin resistant patients undergoing cardiopulmonary bypass. This prospective, open label non-randomized study is performed in the operating room. Patients aged 18 to 90 years scheduled for elective cardiopulmonary bypass surgery with a high risk for heparin resistance are approached for participation. Subjects will be enrolled if they exhibit heparin resistance as defined by protocol after an intravenous loading dose of heparin just prior to cardiopulmonary bypass. Enrolled subjects will receive an intravenous bolus of 500 units of recombinant, human antithrombin (rhAT, ATRYN ®). If the subject remains heparin-resistant, one more IV bolus of 500 units rhAT is given.
Other Name: ATryn®

  Eligibility

Ages Eligible for Study:   18 Years to 90 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Patients undergoing cardiac surgery requiring cardiopulmonary bypass (CPB)
  • Heparin resistant according to this definition: initial activated clotting time (ACT) after an intravenous loading dose of heparin (300 u/kg) is less than 480 seconds

Exclusion criteria:

  • current use of one or more of these medications:

    • warfarin (within 3 days of surgery);
    • streptokinase;
    • tissue plasminogen activator;
    • abciximab,
    • eptifibatide,
    • tirofiban or
    • clopidogrel.
  • known hypersensitivity to goat or goat milk proteins,
  • patients with pre-existing coagulopathy defined as a history of bleeding or laboratory bleeding disorder (e.g., von Willebrand disease, platelet disorder) and
  • patients receiving direct thrombin inhibitors
  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: NCT01547728

Locations
United States, Minnesota
Mayo Clinic in Rochester
Rochester, Minnesota, United States, 55905
Sponsors and Collaborators
Mayo Clinic
rEVO Biologics
Investigators
Principal Investigator: William Oliver, MD Mayo Clinic
  More Information

Additional Information:
No publications provided

Responsible Party: William C. Oliver, Consulatant Cardio/Thoracic Anesthesia, Mayo Clinic
ClinicalTrials.gov Identifier: NCT01547728     History of Changes
Other Study ID Numbers: 11-004125
Study First Received: February 7, 2012
Last Updated: December 20, 2013
Health Authority: United States: Institutional Review Board

Keywords provided by Mayo Clinic:
antithrombin
Heparin Resistant
Cardiac Surgery

Additional relevant MeSH terms:
Antithrombin III
Antithrombin Proteins
Antithrombins
Calcium heparin
Heparin
Anticoagulants
Cardiovascular Agents
Enzyme Inhibitors
Fibrin Modulating Agents
Fibrinolytic Agents
Hematologic Agents
Molecular Mechanisms of Pharmacological Action
Pharmacologic Actions
Protease Inhibitors
Serine Proteinase Inhibitors
Therapeutic Uses

ClinicalTrials.gov processed this record on October 20, 2014