ACC 2013: Restenosis rates low among elderly patients who have stents implanted

March 9, 2013 – This was the first large observational study to assess risks and benefits of stents in an elderly population using national data

There are risks associated with both bare-metal stents and drug-eluting stents (DESs). One risk, restenosis, occurs when scar tissue forms in the stented artery and causes the artery to narrow again, often requiring restenting or, in some cases, coronary artery bypass graft surgery. Compared with bare-metal stents, DESs are associated with a smaller risk of restenosis, but they are more costly and require long-term use of dual antiplatelet therapy, increasing the risk for bleeding complications. Also, DES patients who don’t take antiplatelet therapy have a greater risk of stent thrombosis.

The U.S population is aging; approximately 40 percent of patients who have stents implanted are 65 years or older, and the use of DESs is common in this population. Importantly, elderly patients are already at a greater risk for bleeding complications. A new study was the first to assess the risk of restenosis in patients aged 65 years and older and to develop a model for determining the best candidates for DES implantation. The results were presented at the American College of Cardiology Scientific Sessions. DCRI Co-Chief Fellow Connie Hess, MD, was the lead author.

Researchers linked data from the CathPCI registry and Medicare claims to study patients who were at least 65 years old and had a stent implanted between 2005 and 2009. Researchers then assessed how many patients had target vessel revascularizations, or repeat procedures in the same vessel to determine rate of restenosis. Approximately 75 percent of patients received a DES versus a bare-metal stent, and the overall rate of restenosis was very low, ranging from approximately 3 percent to more than 7 percent, depending on which definition of target vessel revascularization was used. This was the first large observational study to assess this outcome in an elderly population using national data.

“Multiple analyses have shown that drug-eluting stents are more costly than bare-metal stents, but the results have been based on the average population, not elderly patients who make up a large percentage of patients who receive these stents,” said Dr. Hess. “We have shown that the rate of restenosis is low in this population, and we developed models to help predict which patients have the highest risk of restenosis. The highest-risk patients are the ones who may benefit the most from drug-eluting stents, and in whom the risks associated with drug-eluting stents may be acceptable. Targeted use of drug-eluting stents in this population could help to lower costs.”

Other DCRI researchers involved with the study include Sunil Rao, MD; David Dai, PhD; Megan Neely, PhD; and Eric Peterson, MD, MPH, who was the senior author.