CVS’s bid for Aetna highlights a push among health-care companies to find new avenues of growth. Here, a CVS store in downtown Los Angeles on Friday. Photo: Christopher Lee/Bloomberg News CVS Health Corp.’s bid for Aetna Inc. is the culmination of a wide-ranging hunt by the drugstore giant for a deal partner, highlighting a broader effort among health-care companies to find new avenues of growth by combining diverse businesses under one roof. The Woonsocket, R.I., company has been examining different deal possibilities for about six months, according to people familiar with the matter.