University of Florida researchers are planning to test a therapy in which stem cells are injected into the hearts of people with severe coronary artery disease and daily chest pain, to see if it could help restore blood flow by prompting new blood vessels to grow.
The patients on whom the experiment will be conducted do not respond well to traditional medications or surgical procedures designed to restore blood flow, such as angioplasty or bypass surgery.
"The general idea is that by providing these cells of blood vessel origin, we hope to either generate new blood vessels from the growth of these implanted cells or stimulate the heart to regenerate new blood vessels from the cells that reside in it," Carl J. Pepine, lead author of the study, M.D., chief of cardiovascular medicine at UF's College of Medicine said.
"It's not completely clear whether it's the actual cell itself that would do this or whether it's just the milieu and the chemical signals that occur from the cells that would result in this," he said.
The forthcoming double blind, placebo-controlled study is known as the Autologous Cellular Therapy CD34-Chronic Myocardial Ischemia Trial, or ACT34-CMI.
In the study, the researchers will study 15 patients to determine whether a person's own stem cells could be used to effectively and safely treat chronic reductions in blood flow to the heart, improving symptoms and long-term outcomes.
It will also be evaluated whether participants report improved quality of life and exercise tolerance, and whether the heart functions better.
For the study, participants would undergo screening tests and later a series of injections of a protein that releases stem cells from the bone marrow into the bloodstream would be given.
The cells, known as CD34+ stem cells, help stimulate blood vessel growth and during a procedure called apheresis they are harvested from the patient, said Chris Cogle, an assistant professor of medicine at the UF's College of Medicine Program in Stem Cell Biology and Regenerative Medicine.
Participants will then be randomly assigned to receive one of two dosing levels of the cells, or a placebo.
"Physicians will use a catheter-based electrical mapping system to find muscle they think is still viable but not functioning," said R. David Anderson, an associate professor of medicine at UF and director of interventional cardiology.
After the procedure, patients will be periodically evaluated by echocardiography and magnetic resonance imaging over the course of a year.
One trial focuses on patients who have had a heart attack within a week preceding study enrolment, the second focuses on patients whose heart attack occurred within the preceding two to three weeks, and the third focuses on patients with congestive heart failure or chronic chest pain that has not responded to traditional treatment.