Differences in Drug-eluting Stents in Patients with Advanced Coronary Artery Disease

Newswise — Results of a multi-center, prospective study involving two leading drug-eluting stents were presented today, with data indicating that patients with long areas of vessel blockage (> 24mm) treated with the Cypher Sirolimus-eluting Stent had less in-stent late loss (tissue growth inside the stent) and less in-stent restenosis (reblockage) than patients treated with the Taxus Express 2 Stent or a bare metal stent. Dr. MK Hong of ASAN Medical Center, Korea, presented the results at the Cardiology Research Foundation's 16th Annual Scientific Symposium Transcatheter Cardiovascular Therapeutics (TCT 2004). TCT 2004 is being held this week in Washington, D.C.

"Both drug-eluting stents showed improvement over the bare metal stent in this difficult-to-treat patient population, with the Cypher Stent showing better outcomes among the stents studied," said study principal investigator Seung-Jung Park, MD, Chief of Interventional Cardiology, ASAN Medical Center, teaching affiliated hospital of Ulsan University, Seoul, Korea.

Prof. Park noted that while prior studies of drug-eluting stents have included subsets of patients with long lesions, this is the first to focus exclusively on this hard-to- treat patient population.

"Patients with very long lesions are among the most difficult to treat and at higher risk for restenosis. These findings provide important new information for clinicians to consider when treating these types of patients," said Prof. Park.

The presence of long lesions is only one factor that can place a patient at higher risk for restenosis (reblockage). Other factors include narrow vessels, longer stent length and diabetes, since diabetic patients generally have more inflammatory responses to treatment for blocked vessels and a greater likelihood of cell proliferation (regrowth) that can lead to reblockage.

Study Examined Long-Term Benefits of Drug-Eluting Stents for Challenging Patients The study, involved eight centers in Korea, enrolled a total of 637 patients with long lesions, defined as lesions of at least 24 mm in length treated with stents 28 mm or longer. Patients were treated with the Cypher Stent (n=294), Taxus Stent (n=166) or bare metal stent (n=177) between February 2003 and February 2004 and followed for a period of six months.

The primary endpoint of the registry was six-month angiographic restenosis (reblockage as shown through cardiac imaging). Secondary endpoints included late loss (vessel wall narrowing) and Major Adverse Cardiac Events (MACE), an important safety and efficacy outcome measure which comprises all-cause death, myocardial infarction (heart attack) and target lesions revascularization (TLR or retreatment).

The patient populations in the two arms of the study were well matched at the baseline, including the percent of high-risk patients, including diabetic patients " Cypher Stent: 31.0%; Taxus Stent: 31.9%, and overall stent length " Cypher Stent: 42.8 mm; Taxus Stent: 43.1 mm, though patients in the Cypher Stent arm of the study had slightly narrower vessels (2.80 mm) vs. the Taxus Stent (2.90 mm).

Even with narrower vessels at the baseline, at follow-up, patients treated with the Cypher Stent had 65 percent less in-stent late loss than patients treated with the Taxus Stent (0.27 mm vs. 0.78 mm, p<0.001), and 65 percent less in-segment restenosis than patients treated with the Taxus Stent (7.4% vs. 21.3%, p<0.001).

Additionally, Cypher Stent-treated patients had a larger minimal in-stent diameter (vessel opening) than patients treated with the Taxus Stent (2.45 mm vs. 1.98 mm, p<0.001), which is important for blood flow, and a lower average in-stent diameter stenosis (blockage) than those treated with the Taxus Stent (10.4% vs. 29.3%, p<0.001) at late follow-up.

"This study is important because it shows how drug-eluting stents are performing over the long-term with challenging patients, an important and growing patient population," Prof. Park concluded.

About ASAN Medical Center Founded in 1989, ASAN Medical Center (AMC), the largest medical center in Korea, has led the advancement of medical services. Its Cardiovascular Center, directed by Dr. Seung-Jung Park, performs approximately 2,500 percutaneous coronary interventions (PCIs) and publishes 20 articles in SCI (Science Citation Index) journals annually.

Cypher ® Sirolimus-eluting Coronary Stent is a registered trademark of Cordis Corporation, a Johnson & Johnson Company. Taxus™ Express 2™ Paclitaxel-eluting Coronary Stent System is a registered trademark of Scimed, Inc.