We know that Terok Nor (DS9) was abandoned as part of the Cardassian withdrawal from Bajoran space, but its sister station Empok Nor was located in the Trivas system. In the episode in which Empok Nor is introduced, it's stated that it's only been abandoned for about a year, and O'Brien and Sisko discuss that there hadn't been any Dominion activity around it recently either - implying that Empok Nor is still within Cardassian territory, although perhaps on the far edges.
It seems as though if the Klingons had taken the Trivas system, they would have taken the station as a prize, and the episode "Empok Nor" implies that the drugged soldiers aboard were left as part of a booby trap on the abandoned station rather than being the reason for evacuation.
Are we ever given any indication (either in canon or novels) of why Empok Nor was abandoned?