DALLAS (AP) _ A cancer drug has been shown to stimulate the growth of new blood vessels in oxygen-starved areas of the heart, offering a potential new treatment for people with clogged heart arteries.
The new vessels redirect blood flow around the clogged arteries in an approach that is considered safer than bypass surgery or balloon angioplasty.
Swiss scientists studied 21 people, some of whom received injections of granulocyte-macrophage colony-stimulating factor, or GM-CSF. After two weeks, the 10 who got GM-CSF had substantially more improvement in blood flow than those who did not get the drug, said Dr. Christian Seiler, professor of cardiology at University Hospital in Bern.
The findings were published in Tuesday's issue of the journal Circulation.
``It demonstrates for the first time in humans that the growth of natural coronary bypasses can be promoted using an `old' cancer drug,'' Seiler said.
GM-CSF, one of several proteins called human growth factors, is used in cancer patients to induce blood cell production and to increase the body's number of disease-fighting white cells.
Nearly a quarter of people with coronary artery disease cannot be treated with traditional methods like bypass surgery or balloon angioplasty because they are too ill, Seiler said.
Doctors have been using human growth factor for years to grow capillaries to redirect blood around clogged arteries _ an approach called angiogenesis.
But GM-CSF appears to more effective, because it spurs the growth of interconnecting arterioles, which are larger than capillaries and able to carry more blood, Seiler said.
In bypass surgery, a piece of blood vessel is grafted into place to create a detour around the blockage. In balloon angioplasty, a catheter with a balloon tip is inserted into the artery to push the blockage aside.
Dr. Judah Folkman, a surgeon at Children's Hospital in Boston and a pioneer in the field of angiogenesis, said the GM-CSF findings offer hope to patients too ill to undergo traditional treatments.
``It's the first study in patients which takes a look at a different kind of angiogenic protein that makes a larger vessels that just the little capillaries,'' he said. ``I think it's a very well-done study by a very good group.''