UPDATE 1-Boston Scientific wins FDA OK on drug stents

(Adds details, background, premarket trading, CHICAGO to dateline)

CHICAGO, Sept 25 (Reuters) - Boston Scientific Corp (BSX.N) on Thursday said it won U.S. regulatory approval for its next generation drug-eluting stents.

Boston Scientific, whose shares were bid higher in premarket trading, said it plans to immediately launch its Taxus Express2 Atom Paclitaxel-Eluting Coronary Stent System, the only drug-eluting stent on the U.S. market for use in vessels as small as 2.25 mm in diameter.

The U.S. Food and Drug Administration also approved its Taxus Express2 Paclitaxel-Eluting Coronary Stent System for the treatment of in-stent restenosis, or reclogging of the vessels, in bare-metal stents, the company said.

Stents are tiny wire-mesh tubes that are inserted into diseased arteries to prop them open after they have been surgically cleared of blockages.

Stent sales have fallen in recent years amid concerns that the devices could lead to late stent thrombosis, a small but deadly risk of blood clots forming inside the stent a year or more after implantation.

Boston Scientific sales led the decline as more competitive products entered the market.

Shares were bid at $13.06 and offered at $13.10 in premarket trading, up from their New York Stock Exchange close on Wednesday of $12.61. (Reporting by Debra Sherman, editing by Maureen Bavdek)