There's a lot of "Reefer Madness" -type hysteria (and an equally hyperbolic backlash) involved in the discussion of Anabolics, which is why you rarely get good info pro- or con- regarding the effects of their use.
As an anecdotal note regarding whether someone can just have a heart attack brushing their teeth and die, I had a friend w/no history of drug/etc use, or family history of heart problems, spontaneously have a stroke at 29. Again an anecdotal note, but if it can happen to a relatively normal/healthy young guy it can definitely happen to someone riding their body hard.