Could be anything. Easy to speculate on the internet and find folks that will agree with any conclusion drawn. Best to wish the guy and his family well and wait for more data probably.

That's my internet post on the matter. Take it for what it is

PS, On of my good friends had a heart attack last week, was recording with him last night - he's OK and rehabing now. Genetics can play a role I think, so to diet, so can a little something called luck.