Another obvious cause for the increase in heart disease related deaths which you ignored is that level of treatment and detection of heart disease was reduced due to people less regularly seeking medical care during the pandemic.
But I had the impression that US (maybe apart from NY) was trying to keep business as usual as much as possible.
More or less a lot of companies took some handouts from the government while half the country insisted it was a demonrat hoax and the others stayed home to try and stop having out hospitals blown the fuck out.
A lot of people, including myself, waited a long time for our yearly (or bi yearly if you’re older) visit. I’m sure a lot of older people could have done some preventative stuff to prevent a heart attack. Like getting a stint put in if they had an irregular heart beat, had this happened to a family member in their late 80s.