Stephens analyst Chris Cooley reiterates an Overweight rating and $415 price target on Abiomed's shares despite the recent issuance of a "Dear Doctor" letter related to the Impella RP. Specifically, the letter notes the FDA is evaluating post-approval study results for the RP which suggest a higher mortality rate for patients treated with the Impella RP versus what was noted in prior clinical studies, he adds. The analyst's model estimates sales of the Impella RP will contribute about $48M to FY19 operating results and he points out that the Impella remains on the market and the company is working with the FDA to assess the post approval study data.