In contrast, all 24 of those 57 patients without Q-wave MI's who did not have collaterals had subtotal stenosis of their diseased vessel.

The guidelines offer three classifications of patients based on the number and severity of diseased vessels and the presence of symptoms.

And if they start taking estrogen later, after their arteries have already become narrowed by disease, the hormone may be harmful, because it can cause blood clots in diseased vessels that may lead to heart attacks and strokes.

If medications fail, the next step may be bypass surgery, in which healthy blood vessels are stitched onto the heart to bypass diseased vessels, or angioplasty, using a catheter to force open blocked vessels from the inside, sometimes followed by stenting.

Before that, Dr. Isner had tried inserting a thin tube into the diseased vessel and then placing vegF directly onto the vessel wall.

The procedure is considered less invasive than endarterectomy, which involves the surgical cut down and removal of plaque from the inner wall of a diseased vessel.

The main disadvantage of MIDCAB is that it cannot be used to treat several diseased vessels, especially if arteries on both the left and right sides of the heart are blocked.

Once the doctor found the diseased vessel, he inserted a thinner catheter carrying an uninflated balloon through the guiding catheter.

Their findings in completion angiography at the end of the operation included suboptimal anastomoses, poor lie of the venous bypass graft, and bypasses to not diseased vessels.