DURHAM, N.C. -- Scientists at Duke University Medical Center have delivered therapeutic genes throughout a rabbit's heart and have shown that the genes can both boost heart function on their own and also increase sensitivity to heart-stimulating drugs.
According to the researchers, the experiments, reported in the July 1 Journal of Clinical Investigation, are a crucial step in developing a genetic treatment for congestive heart failure. This debilitating and deadly condition develops when heart muscle loses its ability to stretch and contract, usually due to clogged arteries caused by coronary artery disease. People with congestive heart failure often experience fatigue, weakness and an inability to carry out routine daily tasks. There is currently no effective means to reverse heart failure, only to treat symptoms.
The research is funded by grants from the National Institutes of Health and the American Heart Association (AHA).
According to the AHA, about 400,000 new cases of congestive heat failure are recorded every year in the United States. Death rates from congestive heart failure tripled between 1974 and 1994, making it the leading cause of hospitalization among people 65 and older and costing more than $10 billion a year.
Research team leader Walter J. Koch, an associate professor of experimental surgery, and his colleagues have been working for several years to find ways to efficiently deliver genes to the heart to boost heart function.
In their experiments, the scientists first incorporated the therapeutic
genes into a live but disabled common cold virus. Then, in a surgical technique
that was a key to their success, the scientists injected the virus into the left
ventricle of live rabbits while the aorta was clamped for a few seconds. This
technique allowed the virus enough time to spread through all the coronary
vessels to reach a majority of the heart muscle. Clamping the aorta is som
Contact: Karyn Hede
Duke University Medical Center