TROY, Ohio-Health officials have decided to close two aging hospitals in Piqua and Troy and build a $43 million replacement hospital between the two cities. The Miami Valley Health Improvement Council, a health planning body, voted 14-4 on March 13 to permit Upper Valley Medical Centers to build the 128-bed hospital by 1999. The council's decision may have ended a two-year battle by Save Our Hospitals, a citizens' group opposed to the hospital closings. Abou t 250 members attended the meeting Wednesday. They asked planners to consider consolidating services at one of Miami County's two hospitals in Troy and Piqua. The hospitals are 10 miles apart and duplicate many services. Upper Vall ey officials rejected the idea, arguing that the hospital system would lose patients. They said they will save $15 million a year in operating costs by consolidating staff and moving to a new, more efficient hospital. Bob Thimmes, president of the health planning council, said a new hospital was the only option. "Upper Valley will die, literally, if they don't get centralized, state-of-the-art facilities and services," he said.