I read it without having any idea what the Hunger Games books are even about (beyond the title) and didn't find it at all confusing. I think you should be fine.

I will agree with the nonny below, though, that the epilogue detracted from my overall enjoyment of the story. Then I did wish that I had read the original books, because maybe it would give me a good idea of why the epilogue was included. Other than some Dean/Cas is pasteded on, (not so) yay.