Cardiovascular Systems Inc. (CSI) has entered into a definitive merger agreement under which CSI will merge with Struggling biotech company Replidyne Inc in an all-stock merger valued at up to $40 million.

CSI is a medical device company focused on developing and commercializing interventional treatment systems for vascular disease.

Under terms of the agreement, Replidyne will issue new shares of its common stock to CSI shareholders whereby former CSI shareholders are expected to own 83 percent of the combined company, and Replidyne shareholders are expected to own 17 percent of the combined company on a fully diluted basis using the treasury stock method.

The boards of directors of both CSI and Replidyne have unanimously approved the transaction, subject to customary closing conditions, including approval by the shareholders of each of CSI and Replidyne.
Post acquisition, Replidyne's name will be changed to Cardiovascular Systems Inc., and the combined company will apply for listing on the Nasdaq.

The merger is expected to close in the first quarter of 2009.