The Effect of Exercise on Stem Cell Mobilization and Heart Function in Patients Undergoing Cardiac Rehabilitation
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|ClinicalTrials.gov Identifier: NCT00053456|
Recruitment Status : Completed
First Posted : January 30, 2003
Last Update Posted : March 4, 2008
This study will look at the effect of a cardiac rehabilitation exercise program on release of stem cells from the bone marrow and on heart function. Stem cells are primitive cells produced and released by the bone marrow, circulate in the bloodstream and develop into white blood cells, red blood cells and platelets. Some stem cells may also develop into other kinds of cells, including those that make up heart muscle, especially if the heart has been damaged or is not getting sufficient blood. Stem cells called endothelial progenitor cells (EPCs) are thought to form new blood vessels that can carry blood to areas of the heart muscle that are oxygen-deprived because of clogged arteries. Previous experiments have shown that some EPCs can be forced out of the bone marrow by exercise. This study will examine whether repeated exercise and lifestyle changes increase the number of EPCs released into the bloodstream and if these cells improve heart and blood vessel function.
Patients 21 years of age and older with coronary artery disease may be eligible for this study. Candidates will be screened with a medical history and physical examination, including a cardiovascular evaluation, and blood tests. The participants will be enrolled in a 2- to 3-month cardiac rehabilitation program that includes 24 to 36 60-minute sessions of exercise, plus instruction on lifestyle changes related to diet, stress management, and relaxation techniques. In addition, participants will undergo the following tests and procedures:
- Brachial reactivity study: This test measures how well the arteries widen. The patients rest for 30 minutes, and then an ultrasound device is placed over the artery just above the elbow. The device measures the size of the artery and blood flow through it before and after the patient is given a spray of nitroglycerin under the tongue.
- Blood tests for EPC levels and genetic testing: These measure EPCs and determine whether certain genes that may regulate EPC function are turned on or off. Genes are made up of DNA, the molecules that lead to the production of proteins by cells. Some of these proteins may be important in releasing EPCs from the bone marrow to travel in the bloodstream to the heart and repair blood vessels and muscle cells.
- Treadmill exercise testing: Patients exercise on a treadmill with continuous monitoring of the heartbeat and frequent measurements of oxygen saturation, using a finger clip device. The patient continues to exercise until moderate chest pain, shortness of breath, or fatigue develops.
- Questionnaire: Patients fill out a 15-minute questionnaire about their general physical and mental health status at the first and last visits to the clinic.
- Magnetic resonance imaging (MRI) of the heart: Patients who are eligible to undergo MRI have this test twice during the study, once before beginning the rehabilitation program and again after completing the program. The MRI shows heart function and blood flow in the heart. For this test, the patient lies on a stretcher inside a long narrow cylinder (the scanner). During the scan, the drug dipyridamole, which increases blood flow to the heart, is infused into a vein of the hand or arm. Another drug, gadolinium, is also infused to brighten the images produced.
|Condition or disease|
|Study Type :||Observational|
|Estimated Enrollment :||50 participants|
|Official Title:||Stem Cell Mobilization For Improvement in Vascular Function and Myocardial Perfusion in Patients Undergoing Cardiac Rehabilitation|
|Study Start Date :||January 2003|
|Estimated Study Completion Date :||January 2006|
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 ClinicalTrials.gov identifier (NCT number): NCT00053456
|United States, Maryland|
|National Heart, Lung and Blood Institute (NHLBI)|
|Bethesda, Maryland, United States, 20892|