I know people who have had 6 or 7 heart attacks and are still going strong. Your Dad will have to make some lifestyle changes. No more smoking, losing weight, watch stress levels, change in foods he eats, cutting out fats, sugars, enriched foods and using whole wheat instead and olive or canola oil instead of hydrogenated oils, exercise, leaving junk foods alone and less salt (diet soda is loaded with salt). If he follows his Doctor's orders and takes his meds and changes his lifestyle there's no reason he can't live to a ripe old age.