is there a query I can run against oem repository database to see all indexes across our 600+ db env

we are running oracle 12c and 11g databases (over 500 databases) on windows 2008 r2 and windows 2012 r2 servers.  we use oem 12.1.0.5 and recently we had an issue where a database had over 600

unusable indexes.  we did not receive any alert about this from oem so I am looking into options for this.

either a metric per db that shows me when indexes are unusable or maybe a report across the entire oem env (via repository db views) to find any db/index that is in UNUSABLE status.

I have many queries I use often against the oem repository for database statuses, sql port, etc but so far can't find where the index status is stored in the repository views.