Executives at Louisville-based health insurer Humana and its rival Aetna made backup plans, including changes to reassign and cut employees, in the event their $37 billion acquisition tanked. In fact, a few weeks before the announcement Feb. 14 that the rivals mutually agreed to break up, Humana cut 500 positions in its At Home division. And this week, officials confirmed that they intend to trim an unspecified number of positions while adding roles that fit more closely with the company's latest growth strategies. It's part of the blueprint for moving ahead as an independent company. "I'm sure they had a Plan B and I'm sure that's what they're implementing from" now, said Robert W. Klein, an associate professor and an authority on risk management and insurance at Georgia State University. Klein and fellow Georgia State professor William Custer prepared an analysis of Kentucky's health insurance markets after Aetna applied to state's insurance regulators for approval to acquire Humana.