How to prevent getting heart attack or stroke from overwork?

No.12905392 ViewReplyOriginalReport
https://en.wikipedia.org/wiki/Karoshi

Have to work at least 20 hours a day (IT work) but I don't want to get a heart attack or stroke. It says that death from overwork is caused by stress and bad diet. It says nothing about lack of sleep aka sleep deprivation. Since stress is completely mental, doesn't that mean one just has to have a totally calm/relaxed, meditative, almost nihilistic and positive/optimistic mindset at all times to not trigger the "bad" hormones and/or increase heart rate and not cause damage to the cardiovascular system (primarily the heart) and still be able to work very long hours?