What: Shares of Cardiovascular Systems (NASDAQ:CSII), a medical device company with a focus on minimally invasive surgery products used to treat vascular disease, were down more than 20% in early trading after the company released preliminary results for the most recently completed quarter.

So what: The company reported that it expects revenue from its fiscal first-quarter, which just ended on September 30th, to come in around $43.9 million. While that number would represent an 11% rise over the year-ago period when excluding the $1.9 million reported last year when it was still selling Asahi guide wires, it is well below the range of $48.5 million to $50.0 million that management guided for during August's fourth-quarter release.

Results might not look great on the bottom line either, as the company expects to report a net loss for the quarter between  $(0.41) to $(0.43) per share, which is worse than the $(0.38) to $(0.40) range that management was previously expecting.

Both of these numbers are well below what analysts were looking for as well as they were expecting revenue of $49.37 million for the quarter and for net-loss per share to come in at $(0.39).

In the press release David L. Martin, the company's Chief Executive Officer, stated:

"We continued to make progress on our sales optimization strategy to significantly expand our sales organization, while cross training representatives to sell both peripheral and coronary applications. However, as our recent results suggest, some aspects of the transition have been challenging."

Martin noted that they believe they have taken the appropriate actions to address the company's struggles, and he expects the majority of these actions to be completed by the third quarter of its fiscal year.

Now what: Investors should remember that these numbers are preliminary and that actual results could turn out better or worse than reported in this release after auditors have a chance to review the numbers.

Personally, when I see a company I own report bad numbers for two quarters in a row I tend to hold on and see if management can get the company back on track quickly, but I don't look at the falling share price as a buying opportunity as there could always be more trouble ahead.

If management can turn things around then today's share price could represent a nice buying opportunity. If the company continues to struggle then there could certainly be more downside ahead.

Since this is the second quarter a row that results have been disappointing new investors should probably approach Cardiovascular Systems stock with a healthy dose of caution.