The approval of a next-generation cardiac stent from Boston Scientific Corp. won cheers from Wall Street analysts Wednesday, though some expressed concern about the overall market for the tiny mesh struts.

The Natick, Mass.-based company said Tuesday night that the new stent, called Promus Element Plus, will be launched immediately in the United States. Executives called it a "milestone" event for the medical technology company, which employs about 5,000 in the Twin Cities.

The stents, tiny scaffolds that open clogged arteries leading to the heart, will be manufactured in Maple Grove and in Ireland. The Promus stent is coated with a drug called Everolimus, which prevents reclogging.

Collins Stewart analyst Tao Levy said in a note to investors Wednesday that the approval means Boston Scientific "regains its mojo."

David Lewis, an analyst with Morgan Stanley, characterized the approval as an "early Christmas present" for Boston Scientific -- a development that is critical to the company's quest to improve margins.

But Rick Wise, an analyst at Leerink Swann, said other "moving pieces" affecting the $4 billion stent market prompted him to keep his current rating of Boston Scientific unchanged, despite the news.

Wise cited the highly competitive landscape for stents -- Boston Scientific competes with Abbott Laboratories and Medtronic Inc. -- as well as pricing pressure and new concerns about the FDA investigating a rare problem in which Promus stents shrink or lengthen in the body after implantation.

"Long-term implications [of FDA approval] are likely modest," Wise wrote in a note to investors.

Larry Biegelsen, of Wells Fargo Securities, wrote that "market share could be negatively impacted" by the FDA investigation. Still, he predicts U.S. sales of Promus Element Plus of $504 million in 2012.

Boston Scientific has been selling a stent under the Promus name, but paid Abbott 40 percent of sales under a royalty agreement. Once Boston Scientific transfers Promus technology to the Promus Element Plus stent, it no longer will pay fees to Abbott.

After Boston Scientific's $27 billion purchase of Guidant Corp. in 2006, it sold Guidant's highly coveted stent business to Abbott because of antitrust concerns.

Boston Scientific will take a $40 million pretax charge in the fourth quarter as a result of the FDA approval and launch related to "inventory issues that will impact gross margins."

Boston Scientific spokeswoman Denise Kaigler predicted the launch of the new stent "will be well received by U.S. physicians, based on its wide acceptance and leadership position achieved in international markets."

Promus Element Plus was approved in Europe in 2009.

The U.S. approval came a bit earlier than anticipated, although it failed to significantly move Boston Scientific's stock on Wednesday. Shares closed at $5.32, up a penny in a down market overall.

Janet Moore • 612-673-7752