Rethinking Drug-Coated Stents for Millions

Dec. 8, 2006— -- Doctors may reconsider which of their patients should receive drug-coated stents in light of the recommendations by a Food and Drug Administration panel of expert advisers.

Patients with conditions not specifically approved by the FDA for treatment with drug-coated stents make up nearly two-thirds of the cases in which the devices are used. Because of this, the recommendations could affect millions.

Over the course of the two-day meeting, the panel agreed that the use of drug-coated stents is "not detrimental" in approved cases. However, the panel did acknowledge data showing these devices increase the likelihood of clot formation, even in these patients.

In "off-label" patients -- those whose heart conditions fall outside of FDA approval criteria -- the panel expressed concerns that the increase in clot formation could have health risks.

"For those people who got their stents off-label, there was the concern of an increased risk of stent thrombosis leading to death and [heart attack]," says Dr. George Vetrovec, chairman of the division of cardiology at Virginia Commonwealth University and a panel member. "But that increased risk is probably also true of bare metal (nondrug-coated) stents as well."

Vetrovec says the main finding of the panel is that more research is needed to determine the long-term risk of drug-coated stents.

"Time and time again, we came back to the fact that there was not enough data for the answers that people wanted," he says.

Meanwhile, two studies earlier this week suggested there is an increased risk of heart attack and death when patients with drug-coated stents stop taking anti-clotting medications.

Stents are tiny tubes of metal mesh used to prop open clogged coronary arteries so the heart can receive an adequate blood supply. Manufacturers developed drug-coated varieties of the stents to solve the problem of scar tissue closing the artery back up -- a condition called restenosis.

However, two studies this week in the Journal of the American College of Cardiology and the Journal of the American Medical Association suggest that unless patients who receive drug-eluting stents continue to take Plavix indefinitely, they could more than double the risk of heart attack or death.

At the beginning of the FDA discussions, FDA reviewer Andrew Farb described the increased risk as "small but significant."

Studies presented at the meeting demonstrated a modest increase in clotting problems associated with drug-coated stents. Vetrovec says this finding could mean a change in guidelines for how long patients continue to take anti-clotting medication after having a stent put in.

"There was a lot of talk over the need for [anti-clotting drugs] beyond the three- to six-month period, which is in the current package instructions," he says, adding that patients with drug-coated stents will now likely be advised to take the medicines for at least one year.

Some experts who were present at the meeting say a current lack of definitive data of the long-term effects of drug-coated stents in patients obscures the true threat to patients.

"Clearly, the companies have taken the point of view that if you look at the whole collection of data, everyone is making a big deal over nothing," says Dr. Richard Shemin, professor and chairman of cardiothoracic surgery at Boston Medical Center, who attended the hearings. "And some believe that just staying on the anti-clotting therapy will solve the problem."

Shemin says additional trials should be performed to truly assess the safety of the devices.

Millions worldwide have at least one drug-eluting stent in their bodies, and today most of the 800,000 patients per year who have angioplasty operations receive a drug-eluting stent.

And many of these patients may be alarmed at the news that going off their clot-busting medications could increase their risk of death.

"Patients are scared to death believing that they have a 'time bomb' in their chest," says Dr. Carl J. Pepine, chief of cardiovascular medicine at the University of Florida in Gainesville.

Since receiving two stents in February, Mark Edmonds' quality of life has improved dramatically, the 42-year-old says.

"I feel like a human being again," Edmonds says. "I haven't had any bad side effects so far."

Edmonds, who works for a plumbing and heating supply company in Summit, Ill., is one of the hundreds of thousands of Americans who received DES devices last year.

But now, new research suggests that patients with DES devices must continue to take their anti-clotting medications indefinitely. Doing otherwise could more than double their risk of a heart attack or death.

And since a year's supply of the clot-busting drug Plavix costs roughly $1,400, the findings could saddle patients with a long-term economic burden.

Edmonds says even though his Plavix is partially covered by insurance, he still pays $50 per month in co-pay. With a dozen other drugs to buy to keep his blood pressure in check, he says his monthly medicine bills can add up.

But now he says he can no longer afford to put Plavix at the bottom of his list.

"I wish I would have known about that risk, because I've missed taking my Plavix before for about 2½ to three weeks because I couldn't afford it," Edmonds says. "I wish it would have been explained to me."

Despite the new findings about drug-coated stents, previous research shows that they still give better short-term results than their bare-metal predecessors, which do not have a drug coating.

Jean Redstone, a patient in her 60s who received a bare metal stent in January 1997, says her artery closed back up only weeks after the stent had been put in.

"My doctor told me at the time not to worry about it, but it did turn out my stent was failing," she says. "My next stress test showed that my heart was not getting enough blood. It was very upsetting."