Hello, Is there any history of chest pain or heart attack? Has angiography been done anytime in the past? First angiography should be done if there are blockages they should be opened. If not and working capacity is this much only, then special type of pacemaker called as AICD is indicated and should be put. Surgery is not a big surgery and although infection risk is bit higher if sugar is well controlled and with antibiotics risk of infection is less. This will protect him from sudden cardiac death. so my advice is angiography followed by AICD. Also lifestyle modification like avoiding fatty, oily and high calorie diet. Have low salt diet and monitor blood pressure regularly once or twice a week. Regular exercises like brisk walking, jogging according your capacity at 30 min a day and 5 days a week. Lots of green leafy vegetables, fruits, fish once or twice a week, avoid meat. Avoid smoking and alcohol if any. There shouldn t abdominal fat deposition or obesity. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Sagar Makode