I have the opposite issue. All of the red piriforms I've tried so far have done horribly in my garden. The pink heart has done okay in my pre-grafting growouts and the two grafted plants I'm growing this year are promising.
I choose to go by Tania's site for names/descriptions as the seeds I received labeled Cuor Di Bue match what she describes -
http://tatianastomatobase.com/wiki/Cuor_Di_Bue versus
http://tatianastomatobase.com/wiki/Cuore_Di_Bue