Heart surgery is performed to correct problems with the heart. The most common type of heart surgery is coronary artery bypass grafting. This is when surgeons take healthy veins or arteries from a different part of the body to go around blocked arteries. This type of surgery reduces the risk of heart attack. Other heart surgeries include, repairing or replacing valves, repairing abnormal or damaged heart structures, implant a device to normalize heart rate and improve blood flow, or a heart transplant.