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Evaluating the Role of Thrombin in Saphenous Vein Graft Failure After Heart Bypass Surgery

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: NCT00481806
Recruitment Status : Unknown
Verified May 2013 by Robert Poston, University of Arizona.
Recruitment status was:  Recruiting
First Posted : June 4, 2007
Last Update Posted : May 10, 2013
University of Maryland, Baltimore County
Information provided by (Responsible Party):
Robert Poston, University of Arizona

Brief Summary:
Heart bypass surgery, also known as coronary artery bypass graft (CABG) surgery, creates a detour around the blocked part of a heart artery to restore blood supply to the heart muscle. The saphenous vein, located along the inside of the leg, is commonly used to create the bypass in a CABG surgery. An abnormal increase in the blood clotting protein thrombin may cause the saphenous vein graft to close up and eventually fail. This study will evaluate the relationship between thrombin levels and saphenous vein graft failures in people undergoing a CABG procedure.

Condition or disease
Coronary Artery Bypass Thrombosis

Detailed Description:

The saphenous vein, which runs from the ankle to the groin along the inside of the leg, is commonly used as a graft for people undergoing a CABG surgery. The vein is removed from the leg and reattached to the heart to create a detour around the blocked part of a coronary artery. Following this procedure, many people are prescribed aspirin as a way to increase the chance that the graft procedure will be successful. However, saphenous vein graft failure may still occur in some people, indicating a need to understand why this happens and who might be at risk for graft failure. Thrombin, a protein involved in the blood clotting process, is somehow related to aspirin resistance, abnormalities in blood flow, and cell disruption within the saphenous vein, all factors thought to increase the risk of graft failure. The purpose of this study is to evaluate the likelihood that a burst in thrombin contributes to graft failure in people who have recently undergone a CABG procedure using the saphenous vein.

This study will enroll individuals undergoing CABG surgery at the University of Maryland. Prior to and immediately following surgery, an incision will be made in the skin and the time required for the blood to form a clot will be determined. During surgery, participants' blood vessels will be examined using imaging and cell analysis techniques. Blood collection will occur before surgery, immediately after surgery, and on Days 1, 3, and 30 following surgery. A portion of blood will be frozen for future analysis. An x-ray of the saphenous vein will be performed on Day 5 and again at a follow-up visit 6 to 12 months following surgery. Kidney function will be measured at both of these visits prior to the x-ray procedure. At the second visit, health and mental status questionnaires will be completed.

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Study Type : Observational
Estimated Enrollment : 450 participants
Observational Model: Case-Only
Time Perspective: Prospective
Official Title: Thrombin Dysregulation Leads to Early Saphenous Vein Graft Failure
Study Start Date : February 2007
Estimated Primary Completion Date : May 2013
Estimated Study Completion Date : December 2013

Resource links provided by the National Library of Medicine

Primary Outcome Measures :
  1. Amplifying the severity of all three risk factors of Virchow's triad is expected to lead to a synergistic increase in regional thrombin formation [ Time Frame: Measured at 5 years ]
  2. Pressure distention is the main stimulus that creates a loss of thrombin control within the SVG [ Time Frame: Measured at 5 years ]
  3. Accurate tests of graft quality will be developed that provide rapid results for ready translation into clinical applications [ Time Frame: Measured at 5 years ]
  4. Aprotinin or bivalirudin will effectively suppress thrombin generation and its effects within the highest risk grafts [ Time Frame: Measured at 5 years ]

Biospecimen Retention:   Samples With DNA
Whole blood and vein samples

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 90 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
Male and female patients between the the age of 18-90 years belonging to all races will be enrolled in the study

Inclusion Criteria:

  • Scheduled for CABG surgery at University of Arizona University Medical Center (UMC)
  • For females, willing to use a reliable form of birth control for the duration of the study

Exclusion Criteria:

  • Non-dermatologic allergy to intravenous (IV) radiographic contrast
  • Creatinine levels greater than 2.0 mg/dL
  • Pregnant

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): NCT00481806

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Contact: Robert S. Poston, MD 520-626-7951

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United States, Arizona
University of Arizona College of Medicine Recruiting
Tucson, Arizona, United States, 85724
Principal Investigator: Robert S. Poston, MD         
Sponsors and Collaborators
University of Arizona
University of Maryland, Baltimore County
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Principal Investigator: Robert S. Poston, MD University of Arizona, Tucson
Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: Robert Poston, Chief, Division of Cardiothoracic Surgery, University of Arizona Identifier: NCT00481806    
Other Study ID Numbers: 479
R01HL084080-01A1 ( U.S. NIH Grant/Contract )
First Posted: June 4, 2007    Key Record Dates
Last Update Posted: May 10, 2013
Last Verified: May 2013
Keywords provided by Robert Poston, University of Arizona:
Virchow's Triad
Graft Failure
Additional relevant MeSH terms:
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Embolism and Thrombosis
Vascular Diseases
Cardiovascular Diseases