Cardiac Gene Therapy

For the first time, doctors have injected genetically engineered DNA into heart muscles to help restore blood flow to clogged arteries by using a catheter without any anesthesia. Until now, the gene was injected into the heart during a two-hour surgery that required general anesthesia and several days of recuperation.
The new, minimally invasive technique will eventually allow patients to go home an hour after it's completed, said Dr. Jeffrey Isner, chief of cardiovascular research at St. Elizabeth's Medical Center in Boston. It could be a safer alternative to bypass surgery or angioplasty for high-risk patients. Isner performed the procedure in about 30 minutes on Sam Hart, 81, of Rome, N.Y. The early results have been encouraging to Hart, who underwent bypass surgery and an angioplasty operation, but has continued to have heart problems. ``I felt like someone who was waiting for the electric chair, and just found out I was going to be free,'' Hart said. In the new method, a catheter is inserted in the groin and directed to the heart by X-ray imaging. A needle is advanced out of the catheter and injects the DNA into the inner wall of the heart. That leads to production of the protein vascular endothelial growth factor, which stimulates the growth of new blood vessels. Dr. Nicholas Kipshidize, an assistant professor at the Medical College of Wisconsin, said it's too early to tell if the catheter method will he widely used. ``We still don't know the overall success of this procedure,'' he said Researchers have two main concerns about the gene therapy. They fear it could nourish the blood supply of undetected cancers, causing tumor growth, and cause overgrowth of vessels in tissues such as the retina of the eye. Isner said retinal specialists found no changes in the eyes of about 60 diabetic patients who received the gene therapy through the traditional surgical procedure. He added that there hasn't been long enough follow-up to determine the risk of tumor growth, though no new tumors have been seen in patients, and animal data suggests the therapy isn't likely to develop tumors.

Dimitri Bonnville, an American teenager, had been shot in the heart by a nail gun on a construction site, leading to a massive heart attack that destroyed a third of his cardiac cells. His heart was left pumping so weakly that surviving to adulthood was an unlikely proposition. It was evident that this condition of 16 year old heart would only grow worse. Cardiologists made the  decision to use an experimental procedure.

They took tens of thousands of stem cells that are capable of transforming themselves into almost any kind of tissue cells - from Bonnville's blood and injected them into his heart to stimulate heart repair. This treatment was the only hope for this boy. Four months later Bonnville's heart function had improved enough for him to play basket ball. His ejection fraction of the heart ( the percentage of blood pumped from the left ventricle had shot up to 40 % from a low of 25 %.

This success of this type has improved the prospects of heart repair by stem cell.