Modify your risk of sudden cardiac death - don't smoke (obviously); BMI between 21 and 25; eat a Mediterranean diet (veg, grain,nuts, fish and daily alcohol); and exercise 30 minutes each day at 3 - 6 METs. At least if you are a nurse.
Here is the study - worth a careful read. I think its main value is to show just how much depends on lifestyle. What would be your guess on how much your chances of a heart attack decrease if you keep to the four rules above? Though admittedly the diet and (even more so) the exercise rules are quite tough.
Notice how each variable was measured. Also notice that of the 120 000 nurses in the cohort only 80 000 are included in the study, mostly because of non-completion of the diet questionnaire. I'm not sure why they focussed on sudden death rather than all death from cardiovascular disease.