Johnson & Johnson announced yesterday that it would stop making its line of drug-coated coronary stents and its exit from the $4 billion business would include halting the development of Nevo, the newest version of its collection of tiny heart devices.

The New Brunswick-based health care giant said it will remain focused on the overall cardiovascular care business through its subsidiaries, Cordis and Biosense Webster, but it would stop producing Cypher and its sibling, the Cypher Select Plus Sirolimus-eluting stent, by the end of the year.

Seth Fischer, worldwide chairman of Cordis Corp., said the decision was a result of "evolving market dynamics’’ in the drug-eluting stent business. "We see greater opportunities to benefit patients and grow our business in other areas of the cardiovascular device market,’’ Fischer said.

The announcement represented an anti-climatic ending for Cypher, which was hailed at its launch in 2003 as a breakthrough device that would change the way doctors treated patients with clogged arteries.

Cypher, which was the first drug-coated stent to reach the market, was projected to make $3 billion in its first year of sales. But early on, the device experienced some setbacks that caused sales to go into a constant, disappointing slide. While Cypher’s annual sales once reached $2.6 billion, analysts put more recent annual sales at $600 million.

Ultimately, Johnson & Johnson's inability to hold onto a bigger piece of the market and keen competition from rivals like Boston Scientific led to the company's decision to leave the business, according to Wall Street analysts.

The decision to move out of the stent business will also result in Johnson & Johnson closing manufacturing plants in Puerto Rico and Ireland and cutting nearly 1,000 jobs.

"The reality is, in some ways, stents have become a bit of a commodity,’’ said Les Funtleyder, a pharmaceutical analyst with Miller Tabak & Co. in New York. "The result is that pricing has become compressed in developed markets like the U.S. and Europe.’’

Meanwhile, the volume of business has remained flat, Funtleyder said. "It’s become harder and harder,’’ he said, "to make money in this segment.’’

The Cypher, which was Johnson & Johnson’s best selling stent, was still generating hundreds of millions of dollars in sales, but Funtleyder said it wasn’t enough to keep Johnson & Johnson in the stent business.

In the company’s statement, Fischer said competition from products that infringed Cordis’s patents on Cypher had eroded its pricing, sales and marketshare. It also dampened the prospects for Nevo, the latest stent, Fischer said.

Johnson & Johnson said it expects to record a one-time restructuring charge in the range of $500 million to $600 million in the second quarter as a result of the changes at Cordis.

Despite the dynamics of the stent business, Wall Street registered some surprise at Johnson & Johnson’s move. The company’s stock closed at $66.16 a share, down 94 cents, or 1.40 percent.

"I understand the business case,’’ Funtleyder said, commenting on the market’s reaction, "but there was no signal of this coming.’’