Stem Cell Mobilization to Treat Chest Pain and Shortness of Breath in Patients With Coronary Artery Disease

This two-part study will determine whether stem cells (primitive cells produced by the bone marrow that can develop into blood cells or other types of cells) can be pushed out into the bloodstream, relocate in the heart, and grow new heart muscle and blood vessels in patients with chest pain caused by narrowing of their coronary (heart) arteries. The new blood vessels may enable patients to do more activities before experiencing chest pain. Part 1 of the study will evaluate in a small number of patients whether an increase in white blood cells following administration of G-CSF (a drug used to move stem cells from the bone marrow to the bloodstream) is safe in people with coronary heart disease. Part 2 will evaluate the effects of the circulating stem cells on heart function.

Patients 21 years of age and older with coronary artery blockage that limits blood flow to the heart (as shown by coronary angiography within 6 months of entering the study) and causes chest pain that interferes with the ability to carry out daily living activities may be eligible for this study. Candidates will be screened with blood tests, an exercise test, magnetic resonance imaging (MRI), and 24-hour Holter monitoring of heart rate and rhythm. Participants will undergo the following tests and procedures:

Part 1: Patients will be hospitalized at the NIH Clinical Center for 5 days. On the first day after admission, an indwelling catheter (short plastic tube) will be placed in an arm vein to avoid multiple needle sticks for blood sampling. Patients will then exercise on a treadmill. Blood samples will be drawn before the exercise test and 2 hours after the test. The next 2 days, patients will receive a daily injection of G-CSF under the skin. Blood samples will be drawn every day for 5 days to monitor the effect of G-CSF on moving cells into the bloodstream. Additional samples will be drawn to determine the effects of G-CSF on the number of stem cells that become heart cells, as well as any effects on blood clotting ability. After discharge for the hospital, patients will return to the clinic 2 weeks after the initiation of G-CSF treatment for a physical examination, blood tests, and a treadmill exercise test. One month after the initiation of treatment, patients will return to the clinic for a physical examination, blood tests, treadmill exercise test, an MRI study, and fitting with a Holter monitor for 24-hour heart monitoring.

Part 2: Patients will be hospitalized at the NIH Clinical Center for 5 days, undergoing the same procedures as in Part 1, except they will receive G-CSF for 5 days instead of 2. They will also undergo the same procedures detailed for the 2-week and 1-month follow-up visits. Then, at 3 months they will again return to the clinic for a physical examination, routine blood tests, and a treadmill exercise test. This concludes formal participation in the study. However, patients are requested to return to the outpatient clinic once a year for follow-up.