Abiomed Inc.'s (NSDQ:ABMD recent good fortune may make it a prime acquisition target, according to Wall Street analysts. A report from Swiss investment bank UBS AG placed the Danver, Mass.-based medical device maker on its list of 44 potential M&A candidates. That list also includes Thoratec Corp. (NSDQ:THOR) and HeartWare International Inc. (NSDQ:HTWR), two companies which were actually slated to merge two summers ago, before complications with federal regulators caused the companies to scuttle the deal.