I have a bunch of old AGoT cards from when the game first came out. I wonder, can I use those along with the new LCG cards? A friend of mine, who had CoC bought some of the LCG packs, only to see they changed the card backs so they don't go together with the old CCG cards. Is it the same with AGoT??

AGOT card backs stay the same. Cards printed under CCG and LCG have the same card back.

The change happened in Call of Cthulhu, because FFG did not like old card backs saying "Call of Cthulhu. Collectible Card Game" when switching to the "Living Card Game" format.

Thanks for the information!