By David P. Faxon, M.D.
This year, 1.1 million Americans will suffer their first or a recurrent heart attack and about 440,000 of them will die as a result, according to the American Heart Association. Can research help reduce this lethal toll? It can, and it has. But heart disease, which often begins in childhood, remains the nation's leading single cause of death. In recent months, new insights into the causes, treatment and prevention of heart attacks have emerged to help in the battle.
Treatment
Bypass surgery saves lives, tens of thousands each year. Yet it is a major operation that requires cutting the chest open, removing a vein from elsewhere in the body and sewing it into an artery to reroute blood around a life-threatening blockage. Researchers are, however, experimenting with a far less invasive bypass procedure. Here's how it works:
1. A hollow, flexible tube called a catheter is inserted into one leg and threaded up to a clogged artery.
2. Then a physician, guided by ultrasound, pushes a needle from inside the catheter through the artery wall and into an adjacent vein.
3. Next, a tiny balloon is inflated to widen the hole and a tube is inserted between the two vessels.
4. Finally, the vein is blocked off just above the new channel, turning the vein into a substitute artery. Blood from the blocked artery flows down the vein to nourish the previously oxygen-starved heart muscle.
About 10 patients have undergone the experimental procedure in Europe. However, many questions remain about its short- and long-term benefits, possible complications and who might benefit from it. Researchers plan to begin a U.S. study next year.
Diagnosis
Cardiologists often have trouble deciding whether someone with a moderately clogged artery should be treated with drugs or undergo balloon angioplasty, a nonsurgical procedure that can open an artery narrowed by heart disease. The challenge is that angiography, a diagnostic technique used to examine the arteries visually, only provides a two-dimensional image, which makes it difficult to determine the seriousness of a "borderline" blockage (an artery that is not totally blocked). Researchers recently found a better guide than artery narrowing for selecting angioplasty patients. They measured the pressure of blood flowing through a diseased artery and compared it to normal-flow arterial pressure. Previous studies had shown that patients with low blood flow should have angioplasty. The researchers randomized patients with borderline arterial blood flow into two groups. One group had angioplasty; the other did not. After two years the group that did not get the procedure had fewer deaths, nonfatal heart attacks or subsequent procedures to restore blood flow than the angioplasty patients did. The finding indicates that measuring the pressure of blood flowing through a diseased artery can help decide who can be treated with drugs and who should have angioplasty.
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