Hi Babu,
Agent Discovery feature can assist you in identifying the unused trusted host.
Agent Discovery - CA Single Sign-On - 12.52 SP1 - CA Technologies Documentation
Agent Discovery lets you discover instances of different agent types and versions. Once discovered, you can view agent-specific details such as version, state, and others. You can also view a list of agents that are deployed on various hosts in your enterprise and delete the unwanted agent instance entries from the list.
Regards,
Leo Joseph.