Researchers at the University of Texas Southwestern Medical Center in Dallas and colleagues said a multicenter trial compared two types of commonly used stents.
Lead author Dr. Emmanouil Brilakis said stents are small mesh tubes that reinforce the walls of blocked blood vessels. In this study, stents were used to treat blockages in diseased coronary arteries.
The drug coating is contained on a polymer that covers the surface of the stents and eventually elutes -- or washes out of the stent -- over a period of several months or years.
The researchers examined 80 patients -- roughly half of whom had vein grafts with drug-eluting stents and the other half who had the same procedure with bare-metal stents.
The study, published in the Journal of the American College of Cardiology, found that 51 percent of patients with the bare-metal stent had re-narrowing of the vein graft over several months compared with 9 percent of the drug-eluting stent group.
In addition, 28 percent of patients who had a bare-metal stent required another procedure to treat the same blockage, while only 5 percent of patients who had the drug-eluting stent did.