THURSDAY, April 24, 2003 (HealthDayNews) -- In a move that is sure to usher in a new age in cardiology, the U.S. Food and Drug Administration (FDA) on Thursday approved the first drug-releasing stent to open clogged coronary arteries.
"This is going to change the face of interventional and surgical cardiology as we know it," says Dr. Richard Stein, a spokesman for the American Heart Association. "They basically gave [the stent] a blanket approval."
The FDA approved the Cypher Sirolimus-eluting Coronary Stent, made by Cordis Corp., a subsidiary of Johnson & Johnson Co. The drug sirolimus is marketed as Rapamune by Wyeth Laboratories.
Stents, which essentially provide scaffolding within a vessel, have been used routinely since the 1990s to prop open arteries that have been cleared by angioplasty. The devices come with a downside, however, as they also provoke inflammation and scarring, which can cause the artery to close over again.
"You're taking an artery that's got a tiny little aperture and you open it way up and, according to local cells, that's a pretty violent process so they react and inflammation starts," says Dr. Eric Topol, chairman of the department of cardiovascular medicine at the Cleveland Clinic Foundation and one of the investigators in the trial that paved the way for the FDA approval.
"Stenting was plagued by a certain amount of recurrence," adds Dr. Emerson Perin, another investigator and director of new interventional cardiovascular technology at the Texas Heart Institute in Houston. "This eliminates that recurrence rate. It's a huge step forward."
About 800,000 angioplasty procedures to clear blocked arteries are performed in the United States each year. Some 15 percent to 30 percent of patients have restenosis, meaning their artery becomes clogged again within one year and needs to be treated, most often with another angioplasty or bypass surgery. The drug-eluting stent reduced the rate of restenosis by about two-thirds, according to Cordis.
Sirolimus, the drug used on the stent, is an antibiotic and an anti-inflammatory that has already been approved for use in transplant patients. It is produced by a species of bacteria discovered in 1975 on Easter Island in the South Pacific. Its selection was the culmination of more than a decade of painstaking, frustrating work by 25 centers around the world.
"The hardest part was to find a drug, a dose and a polymer [coating, which releases the drug]. This process went on for 15 years," Topol says. "Some drugs made it worse. Some made clotting occur. We were about to give up. The different centers around the world tried hundreds of drugs, hundreds of polymers, hundreds of delivery systems. It wasn't so easy."
The final choice, sirolimus, is released over the 30 days immediately following the procedure, which is apparently long enough for lasting results.
Pretty much everyone who gets a stent will benefit from the new device, even if they eventually develop restenosis. "This drug blocks the inflammation process very dramatically," Topol explains. "Almost every patient would have some renarrowing of some tissue growth, but this really modulates that across the board. Not only does it reduce the need for repeat procedures, but it reduces scar formation in virtually everyone."
Those patients who are at risk for restenosis, of course, will benefit even more. In the trial, 1,058 patients received either the Cypher stent or a traditional uncoated, stainless steel stent. While results were similar in both groups immediately after the procedure, after nine months, the patients with Cypher stent had only a 4.2 percent rate of repeat procedures versus 16.8 percent for those in the conventional stent group. Patients treated with the drug-eluting stent had a restenosis rate of 8.9 percent, compared to 36.3 percent of patients in the other group. The combined occurrence of angioplasty, bypass surgery, heart attacks and death was 8.8 percent in the drug-eluting stent group and 21 percent for the group with uncoated stents.
Some patients who would have had bypass surgery instead of a stent may also be candidates for the new stent, Topol says.
Gradually or not so gradually, the drug-eluting stents will replace traditional stents, Perin says. The main obstacle is cost. According to Topol, the new stents will cost about $3,000 versus about $1,000 for the old ones and the average patient gets almost two stents.
Topol is expecting his first shipment of the drug-eluting stents to arrive late Thursday afternoon. "As of tomorrow, we will be putting them in. We have many patients who have been holding out waiting," he says. The Cypher stents won't be used in every patient but in a sizable proportion, starting with Topol's first scheduled patient on Friday morning at 7.
"We want to do the best for our patients, and this is the best," Perin says. "There's no reason to expose people to recurrence."
More information
The American Heart Association has information on angioplasty and on conventional stents. Cordis has information on the Cypher stent.
