-Not saying you are wrong. But, I'm curious why you assume the worst.
Because he likely did a smorgasboard of drugs back in the day, which likely increased his chance of a number of medical ailments.
Of course, millions of people who never use drugs have a stroke, but substance use/abuse will greatly increase the risk of a stroke, especially when it happens below the average age.
You can only stick these toxins into your body for so long before it hits back.