He died of a complication of COVID, namely a heart attack. His heart was healthy before COVID.
Nowadays, they'd list Covid-19 as the cause of death on his death certificate.
Previously, his primary cause of death would have been the heart attack.
And don't say, yeah, but if he hadn't got the corona virus, he wouldn't have died.
That's not necessarily true. Before the corona virus was ever heard of, people died of heart attacks regularly which were brought on by all kinds of bugs and infirmities.
No way of knowing that about his heart for certain. Many late 35 to 50 somethings with early heart disease show no symptoms but can die suddenly with an MI due to their being no developed collateral circulation in their hearts. That’s why a 75 year old may have a large MI and survive it while a 41 year old promising congressman elect with unknown plaque and cholesterol issues may pass away with the same thing. Having Covid19 certainly didn’t help the poor fellow.