Researchers say patients advised to have angioplasty and a stent to restore blood flow could safely wait and give medications a chance to work.
But those with more severe disease might be able to avoid a future heart attack if they have the surgery right away.
The study in the New England Journal of Medicine offers evidence on how to best treat people with type-2 diabetes and heart disease.
More than 65 percent of diabetics die from heart disease or stroke.
