Endostatin and angiostatin are likely to be tested in human cancer trials this summer and early next year, respectively. Human tests of endostatin to treat heart disease are further down the road. Karen Moulton, lead author of the report in last week's journal Circulation, gave endostatin to mice with severely blocked arteries. It, and a similar drug known as TNP-470, reduced the rate of plaque growth in the mice by 85 percent and 70 percent. There are also these little, teeny capillaries that help to nourish the artery itself.
Diseased arteries have many such capillaries, some of which grow into the plaque and feed it.
Moulton's group showed for the first time that those tiny capillaries contribute to the growth of plaque. Severe blockages of 70 percent or more of the arteries can cause chest pain or other symptoms and are commonly treated with bypass surgery or angioplasty. Lesser blockages, often unnoticed, can also cause heart attacks or strokes. Other researchers are trying an opposite tack. Jeffrey Isner of St. Elizabeth's Medical Center in Boston is trying to encourage blood vessels to grow rather than stop growing.