Short people have fewer incidences of cancer, so I don’t think you can say that lower overall risk of death implies lower risk of heart disease.
As for 2, men in the US are getting shorter because of immigration which adds many confounders.
As for 2, men in the US are getting shorter because of immigration which adds many confounders.
But also short people living longer has so many more possible explanations than less overall fat.
There is no word "heart" or any to this effect in the message you replied to so I did not understand that was what you were doing. I took your question as an attempt to attack the theory on the basis of prevalence of some heart conditions in shorter people.