Heart surgery is a surgical procedure to treat any problem or irregularity of the heart or blood vessels. Different types of heart surgeries deal with different aspects of the heart. An open heart surgery is performed on people who are at great risk of having a heart attack. During the surgery, the surgeons attach a healthy artery to the heart in place of the blocked artery that is blocked by plaque accumulation in the artery. This way the flow of the blood is reopened to the heart muscles.