Despite selling a broad array of medical devices into markets as diverse as cardiology, endoscopy, and endosurgery, Boston Scientific (NYSE:BSX) still largely rises and falls on the success (and the perception thereof) of the company's Taxus drug-eluting stent platform.

Sales at Boston Scientific climbed 49% for the first quarter to about $1.6 billion as worldwide stent sales grew 154% to $721 million (and Taxus sales grew 219% to $686 million). Put another way, nearly 90% of the growth that Boston Scientific saw in the first quarter can be directly attributed to the Taxus drug-eluting stent platform.

While Boston Scientific saw a small erosion of market share in drug-eluting stents (on the order of a percentage point or two), investors shouldn't be overly concerned. The only competitor in the market, Johnson & Johnson (NYSE:JNJ), saw a small boost in its share because of some data from a recent medical meeting as well as some price competition.

Although J&J probably could afford to be more aggressive on price (drug-coated stents are a much smaller component of its growth picture), the company isn't really known for "poisoning the well." As such, Boston Scientific probably doesn't have much to fear in the way of market share loss until Medtronic (NYSE:MDT) enters the market sometime in 2006 and physicians cut back on using the Taxus just so they can try the new Medtronic device.

Drug-eluting stents are presently key to Boston Scientific's growth, but that doesn't mean that the company is totally ignoring its other businesses as well. In just the past week, Boston Scientific has executed three acquisitions of companies (TriVascular, CryoVascular, and Rubicon) that all have interesting technology that fits neatly into the company's existing businesses.

While CryoVascular and Rubicon aren't likely to be world-changers for Boston Scientific, TriVascular's less invasive approach to treating abdominal aortic aneurysms could represent a multi-hundred-million-dollar market opportunity.

It's true that Boston Scientific's growth will eventually succumb to gravity and come down, but that doesn't mean that the business is about to collapse. As a result, it seems a little excessive that a market-leading company with strong margins and returns on assets and equity would be trading near a 52-week low.

Though I've never personally been a major fan of Boston Scientific (going all the way back to my analyst days), I can't help but think that the market has already overreacted to competition in the drug-eluting stent market that hasn't even materialized yet. Companies dependent upon one product line may be riskier than average, but there's no question that they can reap big-time profits when business is good.

For more on the stent wars, check out these other Takes:

Fool contributor Stephen Simpson owns shares of Johnson & Johnson.