ST. PAUL, Minn.--(BUSINESS WIRE)--Cardiovascular Systems, Inc. (CSI) (NASDAQ: CSII), a medical device company developing and commercializing innovative interventional treatment systems for peripheral and coronary artery disease, today reported financial results for its fiscal second quarter ended December 31, 2014. The company’s second-quarter revenues increased 38 percent to $44.7 million, from $32.3 million in the second quarter of fiscal 2014. Coronary revenues grew to $6.3 million. Customer