Piper Jaffray analyst Matt O'Brien recommends shares of Abiomed with the stock down 20% this year and 30% over the past 12 months. The weakness is due to a variety of factors, including the fiscal Q4 miss and softer fiscal 2020 guidance, a dear doctor letter on Impella RP, proposed reimbursement cuts, and concerns about competition, O'Brien tells investors in a research note. The analyst says he does not worry much about reimbursement changes and that the dear doctor letter concerns should subside given the FDA's update yesterday that Impella RP is safe and effective. O'Brien sees scenarios that get Abiomed to "steady" 20% plus revenue growth for the next seven years. Abiomed is his favorite large cap name and he believes the shares "could offer significant upside from current levels." He keeps an Overweight rating on the name with a $320 price target.