Final vocatives are normally not accented. They usually form part of the tail of the IP.
(293) 
How would you respond to that, Imogen? (Laurie Taylor; Liverpool, UK).
(294) Well, let’s introduce him, in a way, by reading I think from the very beginning of the book, Andrew (James Naughtie; Aberdeenshire, Scotland).
(295) That sort of thing, Mark (Sue Townsend; Leicester, UK).
As Wells explains, the deaccentuation of vocatives occurs even when they include new information directed to the addressee. He provides the following examples:
(296) I love you, my little dimpled one.
(297) Stop you, blithering idiot!