Radiation Helps Keep Clogged Heart Arteries Clear
Jan. 31, 2000 (Urbana, Ill.) -- Radiation therapy, which has long been used to kill cancer cells, can keep cleared heartarteries from reclogging. Although the treatment has yet to be approved in the U.S., the results, published in the current issue of Circulation, provide some of the strongest evidence to date that the treatment works, experts say.
To clear out blocked coronary arteries -- the arteries that supply the heart muscle with blood -- cardiologists often perform balloon angioplasty, which expands a partially closed-off artery with a tiny balloon. And in about 90% of patients, physicians now prop open the newly cleared artery by placing a metal coil called a stent inside it, says lead author Paul Teirstein, MD, director of interventional cardiology at the Scripps Clinic in La Jolla, Calif.
But for many patients, angioplasty and stents are stopgap measures: The tissue in the wall of the damaged arteries often overgrows, narrowing the artery again, a process called restenosis. Restenosis can be so bad that physicians have to perform repeated angioplasties, and sometimes even replace the arteries with heart bypass operations, Teirstein tells WebMD.
"Restenosis is a major problem for about 20% of patients who undergo a stent procedure" after angioplasty, Teirstein says.
Since radiation has been used for years in medicine to reduce overgrown tissue, both cancerous and benign, researchers have been testing several different radiation methods in recent years to battle restenosis.
Teirstein and his colleagues tested their method on 55 patients with heart disease who had received stents following angioplasty. After conducting a second angioplasty, the physicians irradiated the inside of the damaged artery in 26 of the patients with a ribbon that contained a radioactive element. The rest of the patients received a non-radioactive placebo. The radioactive element was inserted by threading it along a guide-wire that physicians use during balloon angioplasty to steer the artery-clearing balloons.
The radioactive treatment prevented the need to treat restenosis. Three years after having the radiation, only 15% of the irradiated patients developed reclogged arteries serious enough to require another angioplasty or bypass, but almost half of the placebo-treated patients needed a repeat procedure.