A panel of experts put together by the U.S. Food and Drug Administration looked at the safety concerns surrounding the more than $5 billion drug-coated stent industry. These so-called drug-eluting stents are small metal tubes implanted into blood vessels to help prop up clogged heart arteries after they have been cleared. By coating the stents with a drug, it can reduce the growth of scar tissue that can gradually clog arteries and lead to a heart attack. Recently, researchers are finding that drug coated stents increase the odds of a blood clot when compared to bare metal ones.In response, the FDA convened a panel of experts in Washington to look at recent data suggesting a small but significant increase in the rate of death and myocardial infarction — a heart attack — that may be due to stent thrombosis — a blood clot in the stent — in patients treated with drug. The panel conclusions about the drug-coated stents were mixed, however. The studies show that most patients with drug-coated stents have some increased risk of heart attacks and death but it’s unclear whether this is due to poor health or the devices themselves.
It seems that about 40% of the situations in which the stents are used, the blockage involves just one artery, and the patient’s heart is not significantly damaged. That’s what the FDA envisioned when it approved the use of stents. And in those cases, the panel says the benefits of the stents outweigh any clotting danger.
But the remaining 60% are cases where multiple arteries are blocked, the patient has already suffered a serious heart attack, or other complications are involved. In these more complex cases, the panelists were not confident the benefits outweigh the risk of blood clots. These included cases not originally studied before the devices received FDA approval such as patients whose arteries are narrower or more damaged, or who receive overlapping or multiple stents in a single blood vessel — so-called off-label uses.
The panel concluded that the drug-coated stents are safe when used with healthier patients with less complex problems but may put patients at risk for blood clots. Therefore, the panelists recommended stent patients take blood-thinning drugs for at least a year. They also recommended that the labels on the devices should be updated to warn doctors that off-label use won’t give the same results as seen in generally simpler cases involving healthier patients.
