Citi analyst Ralph Giacobbe sees at least 18% upside from current levels for shares of Envision Healthcare (EVHC) should the company's merger talks with AmSurg (AMSG), as reported last night by the Wall Street Journal, lead to a deal. If AmSurg acquires Envision for 10.7 times 2017 EBITDA, which is where AmSurg is currently trading based on consensus estimates, the total transaction value would be around $8.5B or $30 per Envision share, Giacobbe tells investors in a research note. He reiterates a Buy rating on Envision "whether or not a deal is struck." The stock closed yesterday up 11c to $25.65.