The radiation was given inside the artery to prevent restenosis, a potentially fatal renarrowing of the vessel. Restenosis occurs in about 20 percent of heart patients undergoing procedures such as angioplasty or stenting. Such patients require another procedure or bypass surgery. Stents are metal mesh tubes placed in a blood vessel to prop it open where there is a blockage.
The important thing we learned from the five-year follow-up of our patients is that radiation therapy is a durable treatment for restenosis, says Paul S. Teirstein, M.D., the studys senior author.
Equally as important, he and his colleagues found no evidence of serious adverse effects caused by the treatment, which used tiny beads of radioactive iridium.
We didnt see any unwanted swelling of the arteries, any holes in the arteries, or any other unwanted effects of the radiation therapy, says Teirstein, who is director of interventional cardiology at the Scripps Clinic in La Jolla, Calif.
The study involved 55 patients, 26 of whom received radiation and 29 who took a placebo treatment.
Five years later, the researchers found a significant difference between the two groups when they looked at a combination of three outcomesdeath from any cause, a nonfatal heart attack, or any procedure to restore the hearts blood flow.
In the placebo group, 86.2 percent had bypass or suffered at least one of the three adverse events compared to 57.7 percent in the radiation group.
At the beginning of the study, radiation appeared to be a likely candidate to prevent restenosis and beat this cycle of repeat procedures because it had been used in noncoronary cell-proliferation
Contact: Carole Bullock
American Heart Association