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By Marie Cheine, Medical Writer

Stents are permanent mesh screens that are implanted in blocked coronary arteries by a specially trained cardiologist. They act as permanent scaffolding within an artery, and are used in conjunction with angioplasty (balloon dilatation used to compress plaque against a vessel wall) to aid in allowing blood to flow more freely through a blocked vessel.  Stents work by “tacking up” debris in an artery and sealing tears in vessels. They are placed to keep blocked portions of vessels open after angioplasty procedures.

 The National Institute of Health states that approximately seven million Americans suffer from coronary artery disease or narrowing of the coronary arteries that feed the heart. It is not surprising to learn then that over two million coronary angioplasties are performed worldwide each year, making it more common than bypass surgery. According to angioplasty.org, stents are deployed in more than 70% of all interventions today.  They have virtually eliminated many complications of angioplasty including abrupt and unpredictable closure of vessels that result in emergency bypass surgery.

 Although the late re-obstruction rate after stents is less than after balloon angioplasty, a small percentage still develop blockages at the site due to the growth of scar tissue. A new drug-coated stent aimed at reducing the extent of scar tissue formation has taken a step closer to being widely available on the market in the United States. 

In October 2002, the U.S. Federal Food and Drug Administration Device Advisory Panel voted 8-0 in favor of FDA approval for the Johnson and Johnson’s CYPHER Stent. This stent is coated with a special drug that will control inflammation and prevent re-clogging of the treated vessel.

In a clinical trial with over 1,000 participants, those who received the CYPHER stent experienced a 91% reduction in re-clogging compared to those patients who received a bare-metal stent. According to Jeffrey Moses, M.D., co-principal investigator of the Sirious Trial,  “the remarkable results of the CYPHER™ Sirolimus-eluting Stent are holding.”  The “findings of the SIRIUS trial are very positive and consistent with results of earlier studies. There are no significant differences between our preliminary findings and our final data set. The results continue to support the excellent performance of the product.”