heart stent for use in the U.S.
Types
First-generation stents were made of bare metal. Although they almost eliminated the risk of the artery collapsing, they only modestly reduced the risk of re-narrowing. About a quarter of all coronary arteries treated with bare-metal stents would close up again, usually in about 6 months.
So doctors and companies began testing stents coated with drugs that interrupted the re-narrowing. These are called drug-eluting stents.
In , these reduced re-narrowing cases to less than 10%. They also lowered the need for repeat procedures for people with diabetes, who have a bigger chance of their arteries getting narrow again.
Still, there were concerns that drug-eluting stents were associated with a rare but serious complication called in-stent thrombosis. This is where a blood clot forms in a stent one or more years after it’s implanted.
Because this complication can be fatal, it’s important that people with drug-eluting stents take and an anticlotting drug as prescribed until a doctor tells them to stop.
Innovations
The global market for coronary stents is projected to increase to $10.3 billion by 2021, the consulting firm GlobalData says.
Many new second- and third-generation stent designs are being developed, in clinical trials, or have been approved for use outside the U.S. These include:
- One with a covering that delivers an anti-restenosis drug for months and then basically becomes a bare-metal stent
- A version that is absorbed by the body and disappears after it has done its work
- A stent that uses a coating to quickly create a thin, all-natural layer inside the artery