A new
stent appears safe and effective for preventing arteries from reclosing in coronary heart disease patients, based on one-year results of the first human trial using this stent reported in today’s rapid access issue of
Circulation: Journal of the American Heart Association.
The small study of 42 patients compared standard stents — metal mesh tubes used to keep vessels open after balloon angioplasty — with a new stent coated with the drug everolimus in a biodegradable polymer.
The experimental stent releases everolimus, an immunosuppressant and an antiproliferation agent similar to sirolimus, one of two drugs used for coating stents that the U.S. Food and Drug Administration approved in the last year. Everolimus has shown promise at preventing heart and kidney rejection after transplantation. It acts by inhibiting cell reproduction and reducing cell growth.
The two drug-releasing stents approved for clinical use retain their polymer coatings as long as they are in the body. Most of the polymer coating used on the everolimus stents tested in this study biologically dissolved in a month or so, leaving only the metal stent behind.
“This unique everolimus-coated stent freezes the biological process that leads to the renarrowing of arteries after catheter-based treatments,” said Peter J. Fitzgerald, M.D., Ph.D., senior author and an associate professor of medicine and engineering at Stanford University Medical Center in Palo Alto, Calif. “Not only are the patients free from symptoms, but they have open arteries 12 months after stent implantation.”
Fitzgerald’s intravascular core lab at Stanford analyzed the data. The randomized study was conducted at the Heart Center in Siegburg, Germany, by Eberhard Grube, M.D., Shinjo Sonoda, M.D., and colleagues.
The patients’ average age was 64. Twenty-seven received the everolimus-coated stents and 15 got bare-metal stents. Both groups were similar in age, sex, prior heart attacks, smoking, diabetes and hypertension.
The study’s main clinical focus was on major adverse cardiac events (death, bypass surgery, a revascularization procedure on the stent-treated artery, or heart attack). Only two patients in the everolimus group and one in the control group suffered an event during the first six months and one patient died of chronic obstructive pulmonary disease, which was unrelated to the stent treatment.
No other major events occurred during the last six months of the study.
Before the study, patients in the coated-stent group had artery narrowing of 64.1 percent. At six-month follow-up, the narrowing was only 2.6 percent. Among the bare stent group, artery narrowing was 62.1 percent before the study and 27.8 percent at six-month follow-up.