Deleting spam-marked comments from the database

Is it safe to delete a comment that the Spam Karma plugin has marked as spam from the database? I’m concerned about overloading the database I am running against with an excess of Spam, and so I’d like to create a cron job to do a weekly sweep of all comments that are marked as Spam and delete them from the DB.

I’m just concerned about possible unanticipated effects from this.