Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of Cardiovascular Systems (NASDAQ:CSII), a medical device company focused on the development of minimal invasive vascular disease products, jumped as much as 23% after receiving PMA approval from the Food and Drug Administration to market its Diamondback 360 Coronary Orbital Atherectomy System to treat heavily calcified coronary arteries.

So what: For those who have been following Cardiovascular's Diamondback 360, you likely understand that nothing is a sure thing among medical device approvals, but the Orbit II trial results pretty much spoke for themselves. According to the figures, after 30 days patients using the device were free of major adverse cardiac events 89.8% of the time with a procedural success of 89.1%. Outside the hospital setting, procedural success improved to 98.6%. Cardiovascular Systems plans to market Diamondback 360 Coronary OAS immediately and sees market potential of $1.5 billion.

Now what: Slowly, but surely, Cardiovascular Systems is building up an impressive array of plaque-fighting devices throughout the body. The next big key will be to see how well it's able to launch its new device. There aren't many devices targeting heavily calcified arteries on the market so that should be a positive for the company. But from a valuation perspective I have to think that much of today's news has been more than baked into its share price. While I do like how this story is developing, I'd rather stick to the sidelines for a few quarters until we have some idea how this new device is faring revenue-wise.

Fool contributor Sean Williams has no material interest in any companies mentioned in this article. You can follow him on CAPS under the screen name TMFUltraLong, track every pick he makes under the screen name TrackUltraLong, and check him out on Twitter, where he goes by the handle @TMFUltraLong.

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