Could it be possible that a kitten can pass heartworms to a adult cat if so what's possible thanks for the help.

Heartworms are spread through feces. Poop. if your kitten has them, he/she must be kept away from the other cat. have the other cat tested right away and if all clear, use a heartguard or something like it. the preventer will keep them from getting sick, but it won't cure the parasite if they already have it.