Sirolimus drug-coated stent causes less inflammation than bare metal stents

In the treatment of coronary artery disease, a sirolimus drug-coated stent causes less inflammation than bare metal stents, according to preliminary research presented at the American Heart Association annual meeting by Loyola University Health System, Maywood, Ill.

“Inflammatory response is a sign of advancing heart disease, so the less inflammation the better,” said lead author Dr. Fred Leya, professor of medicine/cardiology, Loyola University Chicago Stritch School of Medicine.

Stents are small stainless steel coils or scaffolds which are used to keep blood vessels open and maintain blood flow to the heart. The drug-coated stent reduces the risk of restenosis (renarrowing) of blood vessels after angioplasty, a common problem with earlier stents, where 30 percent of arteries renarrowed.

“Many times with the earlier stents, tissue cells grew too much scar tissue, renarrowing the artery that the stent was supposed to widen,” said Leya, director, interventional cardiology and director, cardiac catherization lab at Loyola.

Leya said that the FDA-approved stent produces immediate results. “It is especially appropriate for diabetics, because they have smaller arteries and thus a greater risk of restenosis of coronary vessels following angioplasty,” he said.

Participating in the inflammation study were 55 patients: 27 received the drug-coated stent; another 28 patients were treated with a bare-metal stent. Researchers, looking for inflammation markers, took blood samples at baseline, and at 12- to 24 hours and four- to six hours after the procedure.

Results of the study shows that inflammatory response was substantially reduced among patients who received the drug eluting stent compared to the bare metal stent.

The next step, Leya said, is to measure inflammatory markers at one-year.

The stent uses a polymer, which acts as a time-release mechanism over approximately 30-45 days, to deliver medication that inhibits excessive cell growth into lumen of the vessel.

“The advantage of the drug used on this stent is that it does not kill the cells, it just inhibits their growth,” said Leya, noting that when cells die, thrombosis (blood clots) could result.

According to Leya, the latest research shows that with the new stent, renarrowing occurs in only 5 percent to 7 percent of patients. “That is good news for the hundreds of thousands of people who may need angioplasty and a stent this year,” said Leya.

Presenting the study at the AHA meeting is Walter Jeske, PhD, associate professor, department of Thoracic and Cardiovascular Surgery, Loyola University Health System.

Co-authors of the study with Jeske are Gary Maszak, Tony DeMartini, Dr. Omer Iqbal, Dr. Leslie Cho, Dr. Bruce Lewis, Dr. Lowell Steen, Fred Leya and Jeanine M. Walenga, PhD, Loyola University Health System.