Full of fruits and vegetables and low in high fat processed foods. Stay away from fried foods, beef products, and sugary nutrionless junk. Try consuming healthy fats such as almonds and fish. Speak with your doctor or a registered dietician so they can go over other risk factors and recommendations. Are you over weight? Do you also have high cholesterol? Does heart disease run in your family? This question cannot be answered without a proper assessment and evaluation. The things I mentioned will be helpful but may not prevent another heart attack if other areas are not addressed as well. Make sure to drink plenty of water and try to lessen the stress in your life. You must also EXERCISE! Because of your high risk verify with your doctor before beginning an exercise routine. You may also want to seek the help of a qualified personal trainer.