Updated from 8:38 a.m. EDT

Boston Scientific ( BSX) on Tuesday reported first quarter financial results that narrowly beat Wall Street consensus estimates for earnings and revenue.

The company's stock, however, was down $1.43, or 3.3%, to $41.97.

The Natick, Mass.-based maker of medical devices earned $194 million, or 23 cents a share, on revenue of $1.08 billion. The consensus prediction by analysts polled by Thomson First Call was net earnings of $188.4 million, or 22 cents a share, on sales of $1.05 billion.

For the same period last year, Boston Scientific earned $97 million, or 11 cents a share, on sales of $807 million. This period also included $20 million in special charges, or 3 cents a share.

The company said U.S. sales of its Taxus drug-coated stent were $98 million. The stent, used to help ease blood flow in arteries and reduce the risk of heart attacks, went on the market March 4.

Taxus is competing with Cypher, made by Johnson & Johnson ( JNJ), which has been on the U.S. market for 12 months. J&J recently reported that first quarter U.S. sales for its Cypher drug-coated stent was $432 million.

Stents are wire mesh tubes that are inserted into arteries after patients have undergone angioplasty, a procedure that helps unclog plaque from the arteries. Traditional stents - called bare metal stents - reduce the reclogging rates in arteries; but drug-coated stents - which periodically release medicine - have done an even better job of reducing reclogging rates.

Boston Scientific pre-announced first quarter U.S. Taxus sales earlier this month, making Tuesday's announcement somewhat of an anticlimax. "All indications are that second quarter Taxus sales will be impressive," said Helsinki de Zoysa, of Fulcrum Global Partners, in a report to clients following the release of the earnings report.

She expects Boston Scientific to capture 60% of the total $3.3 billion U.S. coronary stent market this year, which included drug-coated stents and bare metal stents. That means Boston Scientific's total U.S. stent sales would jump to $1.9 billion this year from $214 billion last year, said de Zoysa, who has a neutral rating on the stock.

She also predicts that total worldwide stent sales this year could account for more than 40% of what she predicts will be $5.7 billion in corporate revenue.

Boston Scientific earns a neutral rating, she explained, because the company's stock moved up significantly in the last 18 to 24 months, rewarding investors who bet on Taxus early. "But we contend that the market largely knows this today," de Zoysa said. However, there are still opportunities for positive earnings surprises this year related to manufacturing efficiencies, she added. (She doesn't own shares; her firm doesn't have an investment banking relationship.)