Problem: Difficult to know if you have read an issue since last change or to know if you need to follow-up on an issue.

Proposed solution: Let users mark issues as read, unread, and assign follow-up flags, much like you can do with your email items in Outlook.

• Create a table ReadHistory(UserId,IssueId,IssueHistoryId)
  This remembers the IssueHistoryId ('version') last seen by the user. If
  the latest IssueHistoryId is different, then it means the item has changed
  since the user last saw it.

• Create a table IssueFlags(UserId,IssueId,FlagId)
  For a given issue, a user can set a number of personal status flags. We
  will only use a 'follow up' flag for now.

On my view and view issues, add a column to show the current flag(s) relating to an issue.
On view add check box to flag as follow-up.
Flag would default to unread until issue is viewed, then it would change to read. Changing back to unread if the issue is modified.