The big question is then, if consumption of animal fats isn't contributing to heart disease, then what's doing it?

We've found heart disease in Egyptian mummies, so it's been with us as long as paper has been. Is it merely a side-effect of living? Even swine have been found to have narrowing of the arteries (http://vet.sagepub.com/content/19/6/676.full.pdf).

If it's influenced by what we eat, can we change our diets and affect it, or is it entirely genetic? Do dietary changes affect it? If so, does anything reverse it?

I agree, animal fats don't appear to be the single cause, but if they aren't, what is?