The 27-year-old was widely expected to complete a switch to the Reds in July, before the move broke down.
He ended up joining Chelsea on the final day of the transfer window and has admitted that he is far happier to be playing for the Premier League leaders.
"I came for the medical tests and everything was fine and after that they wanted to be sure everything was fine with my heart," the Daily Star quotes him as saying.
"They asked for a specialist for the heart and apparently the guy said they did not 100% agree if I could keep going or had to stop football.
"I didn't understand because they knew before I came. I just told my agent if it is not happening it is because it is not for me. Now I am much better here at Chelsea, I'm very happy to be here and that's why I say everything happens for a reason."
Remy has scored once in three appearances for Chelsea this season.