WASHINGTON — Doctors got a stern warning Tuesday to properly use a popular new drug-coated heart stent that has been linked to blood clots in almost three dozen people, including five who died.

The Cypher stent is a tiny metal scaffold that props open a cleaned-out artery and, unlike other stents, emits a drug to reduce the chances the artery will clog again.

But the drug doesn't prevent a different risk posed by all stents — blood clots that form around the device and can cause a heart attack.

The Food and Drug Administration has received reports of blood clots in 34 Cypher stent recipients. Five of those patients died, although FDA doesn't know if the clots actually caused the deaths, a spokeswoman said.