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.