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Platelet Function And Aggregometry In Patients With Aortic Valve Stenosis

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00156520
Recruitment Status : Completed
First Posted : September 12, 2005
Last Update Posted : April 12, 2010
Information provided by:
University of Rochester

Brief Summary:
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 or disease Intervention/treatment Phase
Hemorrhage Drug: aprotonin; epsilon aminocaproic acid Phase 4

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 40 participants
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Double
Official Title: Jeanne Grace; Head Research Subjects Review Board
Study Start Date : March 2005
Actual Study Completion Date : September 2005

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Bleeding

Primary Outcome Measures :
  1. 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. 2. the von Willebrand antigen test, an immunoassay
    von Willebrand antigen test

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

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

Secondary Outcome Measures :
  1. thromboelastography
    thromboelastography point of care test of hemostatic function

Information from the National Library of Medicine

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Ages Eligible for Study:   Child, Adult, Older Adult
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

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.


Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00156520

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United States, New York
Strong Memorial Hospital, University of Rochester
Rochester, New York, United States, 14642
Sponsors and Collaborators
University of Rochester
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Principal Investigator: Peter L Bailey, MD' University of Rochester, Rochester, NY 14642
Layout table for additonal information Identifier: NCT00156520    
Other Study ID Numbers: 10504
First Posted: September 12, 2005    Key Record Dates
Last Update Posted: April 12, 2010
Last Verified: April 2010
Additional relevant MeSH terms:
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Pathologic Processes
Aminocaproic Acid
Antifibrinolytic Agents
Fibrin Modulating Agents
Molecular Mechanisms of Pharmacological Action