Platelet Function And Aggregometry In Patients With Aortic Valve Stenosis

This study has been completed.
Sponsor:
Information provided by:
University of Rochester
ClinicalTrials.gov Identifier:
NCT00156520
First received: September 8, 2005
Last updated: April 9, 2010
Last verified: April 2010
  Purpose

It is known that patients with aortic stenosis, including those undergoing cardiac surgery for this problem, are prone to developing bleeding problems, particularly of the gastrointestinal tract. It is believed that the shear stress associated with blood flow through the abnormal aortic valve results in abnormal hemostasis. Abnormalities include increased proteolysis of the von Willebrand factor (vWF) and increased binding of the high molecular weight multimers of vWF to platelet membranes with subsequent inappropriate platelet aggregation. Thus, appropriate aggregation of circulating platelets is impaired. Cardiac surgery is associated with significant alterations in hemostasis. Patients undergoing cardiac surgery consume a significant percent of available blood products throughout the United States and are subjected to various and numerous risks associated with blood product transfusion. In addition, excessive postoperative bleeding is a common cause for the need to surgically re-explore the chest cavity in patients who have just undergone cardiac surgical procedures. Such additional surgery carries further cost and risk. Following surgical correction of aortic valve stenotic pathology, associated vWF abnormalities appear to reverse. However, this process can take several days. Although all cardiac surgical patients are at risk for postoperative bleeding, patients undergoing aortic valve surgery for aortic stenosis may be particularly at risk for this postoperative complication. In addition, patients with aortic valve stenosis who undergo noncardiac surgery may have a predisposition to bleeding because of similar underlying shear stress induced abnormal vWF and platelet function. The proposed study is a trial to evaluate the effectiveness of 2 different antifibrinolytic drugs in ameliorating the hemostatic defect associated with aortic stenosis. Aprotonin, an antifibrinolytic agent which also has platelet preserving actions4, will be compared to the currently used anti-fibrinolytic, epsilon aminocaproic acid (EACA).


Condition Intervention Phase
Hemorrhage
Drug: aprotonin; epsilon aminocaproic acid
Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Pharmacodynamics Study
Intervention Model: Single Group Assignment
Masking: Double-Blind
Official Title: Jeanne Grace; Head Research Subjects Review Board

Resource links provided by NLM:


Further study details as provided by University of Rochester:

Primary Outcome Measures:
  • 1. the PFA-100, a platelet related hemostasis test which is a high shear system test of platelet function
    PFA-100, a platelet related hemostasis test

  • 2. the von Willebrand antigen test, an immunoassay
    von Willebrand antigen test

  • 3. factor VIII coagulant activity test.
    Factor VIII coagulant activity test

  • 4. Ristocetin cofactor activity test.
  • 5. thromboelastography (TEG), a point-of-care test of hemostatic function which includes a measure of platelet function.

Secondary Outcome Measures:
  • thromboelastography
    thromboelastography point of care test of hemostatic function


Estimated Enrollment: 40
Study Start Date: March 2005
Study Completion Date: September 2005
  Show Detailed Description

  Eligibility

Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:Study subjects will be competent adult patients who are scheduled to undergo elective aortic valve surgery for severe aortic stenosis.

- Exclusion Criteria: Potential study subjects will be excluded if they are scheduled to undergo elective aortic valve surgery for severe aortic stenosis and any other surgery simultaneously or have been taking aspirin within 6 days of surgery.

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  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT00156520

Locations
United States, New York
Strong Memorial Hospital, University of Rochester
Rochester, New York, United States, 14642
Sponsors and Collaborators
University of Rochester
Investigators
Principal Investigator: Peter L Bailey, MD` University of Rochester, Rochester, NY 14642
  More Information

No publications provided

ClinicalTrials.gov Identifier: NCT00156520     History of Changes
Other Study ID Numbers: 10504
Study First Received: September 8, 2005
Last Updated: April 9, 2010
Health Authority: United States: Institutional Review Board

Additional relevant MeSH terms:
Hemorrhage
Pathologic Processes
Aminocaproic Acid
Antifibrinolytic Agents
Fibrin Modulating Agents
Molecular Mechanisms of Pharmacological Action
Pharmacologic Actions
Hemostatics
Coagulants
Hematologic Agents
Therapeutic Uses

ClinicalTrials.gov processed this record on October 16, 2014