Medicine

Drug Eluting Coronary Stenting

The Food and Drug Administration (FDA), which monitors the use of medical devices, considers both bare-metal and drug-eluting stents to be safe and effective in most people. But, all stents involve some risk. Sometimes the angioplasty procedure itself can cause complications such as a heart attack, blood clots, bleeding or injury to the blood vessels. Both bare-metal and drug-eluting stents have a risk of clotting both early and late after implantation.

It appears that in some people who get drug-eluting stents, there's a small increased risk of blood clots forming in the stent once the drug coating has been used up — sometimes a year or more after stent implantation. This risk is still quite low; about 0.5 percent or less when stents are used for FDA-approved reasons. The risk appears to be slightly higher when drug-eluting stents are used for off-label uses, ranging from about 0.4 to 1.6 percent.

Q. Do drug-eluting stents increase risk of heart attacks ?

An FDA advisory panel found that when drug-eluting stents are used "on-label" — meaning for specific situations approved by the FDA — there was no increased risk of heart attack or death with drug-eluting stents compared with bare-metal stents. However, about 60 percent of the time stents are used for "off-label" indications — meaning for reasons that, while appropriate, are not specifically spelled out in the FDA guidelines. When stents are used off-label, it's generally for more-complex cases, such as in someone who has multiple blockages and other complications.

The FDA panel said when drug-eluting stents are used off-label, there's a small but increased risk of blood clotting that can lead to heart attack and death. But, it's unknown if drug-eluting stents cause this increased risk or whether people in this group tend to be at higher risk in the first place.
There are a variety of potential explanations for blood clots developing later after implantation. Much of it may have to do with how long a person takes anti-platelet medications — aspirin, clopidogrel (Plavix) — which help prevent blood clots from forming in the stents. If these medications are stopped earlier than recommended or an individual doesn't have an effective response to the anti-clotting medications, there can be problems. People also have varying healing times.

Q. What's a stent ?

Stents are metal mesh tubes inserted after an angioplasty into an artery that has become partially or completely blocked. Stents help prevent restenosis — when the artery becomes blocked again. Without the use of stents, about 30 percent of arteries become blocked again...