The claim was "heart disease is not primarily age related". This is a thread about causes of death. If we interpret that claim as "fatal heart disease is not primarily age related", it's straightforwardly false.
Though age also indexes the area under the curve of lifetime exposure to the risks, so it becomes a trivial claim to say that it's age related since it's one of the two axes.
If you have a heart attack at age 50 but with lifestyle intervention (or PCSK9 loss-of-function genetics) you instead would have had it at age 90, then "primarily age-related" is an insufficient claim in this thread.
