Experimental heart stents show promise, doctors say
NEW ORLEANS – A new crop of experimental heart stents have passed some key safety and effectiveness tests and may one day offer alternatives to the controversial stents currently used to keep unclogged arteries open, doctors reported Saturday.
One is designed to dissolve after doing its job, leaving nothing behind to trigger blood clots – a worry with the most popular stents sold now. Another attracts special cells to help the artery heal. A third is super-thin and uses a novel drug to keep scar tissue from reblocking the vessel.
All are seeking a slice of the $6 billion market for these tiny mesh scaffolds, which are placed in arteries during angioplasty, an artery-clearing procedure that more than a million Americans have each year.
Its popularity has faded with news that the drug-coated stents used in most of these procedures can raise the risk of blood clots many months later.
Two brands are sold in the United States: Taxus, by Boston Scientific Corp., and Cypher, by Johnson & Johnson’s Cordis Corp.
At an American College of Cardiology meeting on Saturday, Dr. Gregg Stone of Columbia University said that Abbott Laboratories Inc.’s Xience stent proved “at least as safe and effective” and, by some measures, better than Taxus in a comparison study of 1,000 patients. Stone consults for both companies, and Abbott paid for the test.
Xience’s very thin metal base is coated with a drug called everolimus to discourage scar tissue. It is already sold overseas; the new study is aimed at getting approval in the U.S. and Japan.
Doctors also gave results of the first human study in the world of a temporary stent, Absorb, also made by Abbott. It is designed to hold arteries open for about six months and then completely dissolve over the next two years or so.
No deaths, blood clots or repeat artery-opening procedures occurred among the first 30 patients to get it, and only one mild heart attack occurred in the first six months of use, said study leader Dr. Patrick Serruys of Erasmus University Medical Center in Rotterdam, the Netherlands.
Much more study is needed, but doctors say it would be a welcome alternative to current stents, which are permanent, foreign metal objects that can interfere with imaging tests increasingly used in heart care.
Today, Dr. Marcel Beijk of the University of Amsterdam will report what he termed “encouraging early results” in 152 patients who received a stent called Genous, which is coated with a substance designed to attract stem cell-like cells from the bloodstream to help the artery heal.