It's widely known that diet and lifestyle play a big part in developing coronary artery disease.The condition creates plaque buildup on artery walls, which can cause a heart attack or stroke when completely blocked.However, a new study shows genetics may play a bigger role in developing the disease than researchers thought.According to UPI, Swedish researchers now say that over 30 percent of heart disease cases are caused by genetic factors.Previous analysis indicated certain genetic risk codes linked to heart disease were inheritable in only 22 percent of cases.