Along the genetics line and not remotely gladdening....a mate of mine...his Grandfather, Uncle and Father all dropped with heart attacks at 65..he's 61 this year...
Trying to look after himself as much as possible but has a fairly stressful job.
Now, it could be that they had hard jobs and it distorts the stats but it must be worrying for the guy. I think in his shoes I'd be doing everything by the book.