The Angiogenic GENe Therapy (AGENT) trial is the first placebo-controlled, double-blind trial of the therapy in humans and tested the safety and effectiveness of injecting a growth factor gene into the heart. Researchers found unexpected but significant improvements in exercise times for the sickest group of patients who received the gene therapy.
There is no product approved to stimulate the growth of new blood vessels, says Cindy Grines, M.D., lead author of the study and director of the cardiac catheterization laboratories and the interventional cardiology training program at William Beaumont Hospital in Royal Oak, Mich. We think the growth factor gene used here restarts this natural response. This is a completely new and different approach.
Angina is a major cause of disability worldwide and affects an estimated 7 million people in the United States. The condition, marked by chest pain, occurs when blood vessels cannot get enough oxygen-rich blood to the heart to meet the increased demand during physical exertion. The bodys first response to reduced blood flow to the heart, called ischemia, is to grow tiny new collateral blood vessels to help blood flow around the blockage a process called angiogenesis. For unknown reasons, the process eventually switches off.
Previous studies that injected angiogenic proteins (the products of genes that activates angiogenesis) into the heart to stimulate collateral vessel growth have been unsuccessful in the long term, possibly because the protein has a short half-life and is quickly used up, she says. Gene therapy may be a better approach than protein therapy, Grines adds, because the heart can incorporate the gene and allow continued p
Contact: Carole Bullock
American Heart Association