Now Available for Public Comment: Notice of Proposed Rulemaking (NPRM) for FDAAA 801 and NIH Draft Reporting Policy for NIH-Funded Trials

Collection of Heart Tissue Sample During Open Heart Surgery

This study has been completed.
Sponsor:
Information provided by:
National Institutes of Health Clinical Center (CC)
ClinicalTrials.gov Identifier:
NCT00423553
First received: January 17, 2007
Last updated: March 5, 2008
Last verified: December 2007
  Purpose

This study will collect heart tissue that is routinely removed and discarded during open-heart surgery. The Cardiology Branch of the NHLBI is conducting a variety of laboratory experiments that require a sample of heart tissue. A segment of tissue is routinely cut out of the right atrial appendage of the heart during open-heart surgery to allow the heart-lung bypass machine to be attached to the heart for protection during surgery. This small tissue sample is not re-attached after the bypass machine is removed, but usually destroyed as medical waste.'

People between 18 and 80 years of age who are scheduled to undergo coronary artery bypass surgery or aortic valve replacement surgery may be eligible for this study.

Participants donate the right atrial appendage of the heart, which would normally be destroyed after their open-heart surgery. The tissue will be used by NHLBI investigators in studies directed at learning how to make the heart less sensitive to damage from a heart attack. The samples may be used, for example, to evaluate the effectiveness of known therapies, refine treatment approaches, identify potential new therapies, or explore opportunities for disease prevention.


Condition
Ischemia

Study Type: Observational
Official Title: Modifying Tolerance to Ischemic Injury in Human Atrial Tissue

Resource links provided by NLM:


Further study details as provided by National Institutes of Health Clinical Center (CC):

Estimated Enrollment: 0
Study Start Date: January 2007
Estimated Study Completion Date: December 2007
Detailed Description:

Transient non-lethal ischemia followed by reperfusion activates a cell survival program resulting in increased tolerance to subsequent ischemic injury. This biological phenomenon is termed ischemic preconditioning and is a powerful cell survival program that is operational in the human heart. This program is triggered by signaling intermediates activated in response to the transient ischemia/hypoxia and reperfusion of preconditioning. Characterization of these signaling intermediates should enable us to identify therapeutic agents to augment tissue tolerance to ischemia.

Interestingly, nitrite, which is an endogenous reservoir for nitric oxide (NO), undergoes bioconversion to NO via hypoxia-dependent signaling. Whether nitrite accumulation and bioconversion are components of the ischemic preconditioning program is unknown. Recently Dr. Gladwin and colleagues in the Vascular Medicine Branch unequivocally demonstrated that exogenous nitrite administration is cytoprotective against ischemia-reperfusion injury in murine liver and heart and in the canine heart. Establishing a mechanistic link between the ischemic preconditioning program and nitrite biology would promote nitrite as an attractive compound for future therapeutic interventions. To evaluate this link, we propose to use cardiac right atrial appendage tissue that is routinely excised to facilitate right atrial cannulation for heart-lung bypass. This excised tissue is then usually discarded as medical waste.

We hypothesize that nitrite administration to atrial tissue in an ex-vivo study will demonstrate increased tolerance to ischemic stress compared to atrial tissue not exposed to nitrite. Furthermore, we propose that this cytoprotective effect of nitrite administration will demonstrate equivalency to cytoprotection in response to ischemic preconditioning. Finally, we would employ this tissue to identify nitrite mediated genomic, proteomic and metabolomic modifications in human myocardium, thereby identifying the biological programs orchestrating the cytoprotective properties of nitrite in the human heart.

  Eligibility

Ages Eligible for Study:   18 Years to 80 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria
  • INCLUSION CRITERIA:

Subjects must be 18-80 years of age.

Subjects must provide informed, written consent to donate tissue that would otherwise be discarded post-cardiac surgery.

Subjects undergoing elective coronary artery bypass surgery and or aortic valve replacement surgery.

EXCLUSION CRITERIA:

Subjects currently on oral sulfonylurea therapy for diabetes mellitus

Subjects in atrial fibrillation or having had a history of atrial fibrillation in the 2-week period prior to surgery

Subjects in clinical right heart failure as evidenced by greater than trace pedal edema, an elevated JVP and or by evidence of hepatic congestion.

Subjects unable to give informed consent

  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: NCT00423553

Locations
United States, Maryland
Suburban Hospital
Bethesda, Maryland, United States, 20814
Sponsors and Collaborators
  More Information

Publications:
ClinicalTrials.gov Identifier: NCT00423553     History of Changes
Other Study ID Numbers: 070057, 07-H-0057
Study First Received: January 17, 2007
Last Updated: March 5, 2008
Health Authority: United States: Federal Government

Keywords provided by National Institutes of Health Clinical Center (CC):
Nitrite and Cytoprotection
Ischemic Preconditioning
Atrial Trabeculae Contractile Function
Ischemia

Additional relevant MeSH terms:
Ischemia
Pathologic Processes

ClinicalTrials.gov processed this record on November 25, 2014