Key points from article :
Study data came from nearly 70,000 people who took part in 2 National Health Interview Surveys.
Compared with nonsmokers, regular cigarette smokers nearly tripled their heart attack risk.
Only e-cigarette smokers had a double risk of having a heart attack.
Using both cigarettes and e-cigarettes daily linked to a nearly fivefold increase in heart attack risk.
Study is done by the American Journal of Preventive Medicine.
