Health

Radiation Keeps Clogged Arteries Open: New Heart Disease Treatment

By CBSNews.com staff CBSNews.com staff

January 31, 2002 / 8:43 AM EST / CBS

When we think of radiation therapy, we usually think of it in connection with cancer treatment. But our health correspondent Dr. Emily Senay is here to tell us how it's being used to treat heart disease.

Although we have effective ways to open up clogged arteries, the problem is keeping them from clogging up again over time. A study appearing in the New England Journal of Medicine today finds that using radiation helps prevent another blockage and reduces further heart attacks by 40%. Doctors at New York Presbyterian Hospital participated in the study.

Every year 700,000 Americans undergo angioplasty to open up blockages in the heart by snaking a small tube into the clogged artery and expanding a balloon to push it open. In most cases doctors also place a stent--a small tube made of wire mesh--to help keep the artery open.

"It scaffolds the artery with metal which is then covered by our own body's cells," says Manish Parikh, at New York Presbyterian Hospital.

That cell growth around the stent is part of the body's natural healing process, but it can cause problems.

"That healing process can be aggressive and this tissue can actually grow within the artery and reblock it," says Parikh.

Now doctors have found a solution: By exposing the inside of a reopened artery to gamma radiation for a few minutes, cell growth is inhibited and future blockages are prevented.

"Radiation has been used for years for things like cancer and keloids, and it prevents tissues from growing," says Parikh. "The same idea can be applied within the artery to prevent the tissue from growing."

Having recurrent problems related to angioplasty is not uncommon. About 150,000 patients have this "in-stent restenosis" problem--the return of narrowing--after they have had a stent placed. And until now managing this problem has been difficult. Radiation may increasingly become the way this problem is treated.

Another study also in the journal this morning looked at using radiation the first time a patient gets angioplasty. Early results showed the radiated arteries were less likely to clog later. But there is also concern about using radiation on patients who don't need it. Not everybody's arteries reclog after the stent is put in.

The main side effect noticed is more cases of thrombosis--blood clotting in the vessel, which can damage it--but it is not clear what causes this. An editorial that accompanies these new studies suggests caution in the use of radiation because this use of it new and we may not be aware of what all the possible side effects are yet.

The US Food and Drug Administration recently approved the radiation devices used in this procedure, so over the next several months, it's expected that 50 new centers will begin to offer the treatment.

Also, doctors will soon begin testing a new type of stent that could revolutionize the treatment of heart disease--a stent that has the ability to "thin" blood bilt into it to help prevent clots from forming.