Spring 2008
FDA approves new drug-eluting
stent for clogged heart arteries
For many, drug-coated
stents safe, appropriate
Drug-coated stents were developed as a way to keep blood vessels open after an angioplasty, an artery-clearing operation and a common medical procedure for treating angina and heart attacks. Millions of people with heart problems have been successfully treated with drug-eluting stents, preventing the need for more invasive procedures such as coronary artery bypass surgery.
Concerns about the safety of drug-eluting stents have received much publicity, primarily related to a small increase in the number of blood clots that develop within drug-eluting stents more than one year after implantation.
In December 2006, the FDA convened a panel of cardiovascular experts to review drug-eluting stent safety data. The panel concluded that for many patients, such as those with uncomplicated medical histories who undergo elective stenting of simple coronary blockages, drug-eluting stents remain a safe and appropriate therapy.
Data at one and two years revealed a blood clot rate of 0.5 percent. Follow-up continues to ensure that these encouraging results remain unchanged.
The Endeavor study submitted the largest, most wide-ranging patient population submitted to the FDA in support of a drug-eluting stent, including more than 4,100 patients, followed up for as long as four years. This clinical research has shown that Endeavor provides a consistent and sustained reduction in the need for repeat procedures compared to a bare-metal stent, while also maintaining an excellent safety profile.
Continued efforts from various companies are underway to develop absorbable stents, alternative coatings, and delivery systems to allow the expansion of patient subsets who can benefit from this technology thereby avoiding coronary bypass surgery.
Dr. Cleman is director of the cardiac catheterization lab at Yale-New Haven Heart and Vascular Center. Dr. Cleman also serves as professor of internal medicine and cardiology at Yale School of Medicine.
A new drug-coated stent has been approved by the U.S. Food and Drug Administration (FDA) to treat people with narrowed coronary arteries, the vessels that supply blood to the heart. The Endeavor® Zotarolimus-Eluting coronary stent is the first drug-eluting stent approved since 2004. Drug-coated stents have come under scrutiny recently over concerns that users may be at greater risk of a rare blood clot known as a stent thrombosis.
Manufactured by Medtronic, Inc., the Endeavor device is a tiny metal mesh tube coated with a small amount of a new drug, zotarolimus, developed only for use on a stent. It is crimped around a balloon and delivered to the narrowed section of the coronary artery via a long, thin catheter during a procedure known as an angioplasty. Once the stent is positioned, the balloon is inflated, expanding into the vessel wall where it remains in place. There it acts as a mechanical scaffold to keep the artery open. Slow release of zotarolimus over time prevents restenosis, or re-narrowing of the artery, when new tissue begins to form.
According to the FDA, Medtronic will follow patients who participated in clinical testing for five years. The company also will conduct a 2,000-patient post-approval study to evaluate the long-term safety and effectiveness of the device.
"The Endeavor drug-eluting stent provides cardiologists with another option for treating the one million patients who undergo an angioplasty procedure every year to open their clogged coronary arteries," said Daniel Schultz, MD, director of the FDA’s Center for Devices and Radiological Health. "This important approval is the result of a substantial amount of clinical evidence and a careful review by both FDA and its advisory committee."
Medtronic conducted seven clinical trials of the device, in which the company said it was shown to significantly reduce the number of major coronary events, including heart attack, cardiac death and surgical procedures to reopen stented arteries compared to a bare-metal stent.
The number of adverse events experienced by patients implanted with the Endeavor stent was similar to those that occurred in patients implanted with bare-metal stents and existing drug-eluting stents.
Before drug-eluting stents were available, between 15 and 30 percent of patients experienced restenosis within a year, which requires a repeat angioplasty. This number has dropped to 10 percent of patients since drug-eluting stents entered the U.S. market in 2003.
For more on this topic, see:
- Heart Health Online, U.S. Food and Drug Administration
- American Heart Association
Other cardiac health resources
- Cardiac Services, Yale-New Haven Hospital
- Women's Heart Program, Yale-New Haven Hospital
Previous issues of HealthLINK — Cardiac
- November 2007- Stem cell therapy shows promise in regenerating damaged heart muscle
- November 2006- Heart disease linked to overweight teens
- April 2006- Heart attack patients do better at hospitals specializing in angioplasty
- July 2005- ICDs benefit many patients with heart failure
- May 2005- Broken heart syndrome mimics heart attacks
- February 2005- Treating heart failure in adult patients with congenital heart disease
- January 2005- Risk of stroke lower with off pump surgery
- November 2004- New cholesterol guidelines for high-risk patients
- August 2004- Simvastatin cuts heart risks for people with diabetes
- May 2004- Exercise improves survival rate for heart failure patients
- March 2004- Tougher blood pressure goals established
- January 2004- New blood test predicts cardiac risk
- Archive