TriggerStoredata files in DocumentStore directory affecting performance?

We are experiencing performance issues. I see 14 TriggerStoredata files in the /IntegrationServer/DocumentStore directory. These seem to represent more documents than there are in MWS Clients. Also, some of the files’ ‘Changed Date/Time’ values are several months old and the files are quite large. They seem to be impacting how long it takes for IS to start and, perhaps, performance. Can the files, that haven’t been updated recently, be safely deleted if we are certain there are no unprocessed documents?

Your help is appreciated.