Heart disease, also called cardiovascular disease, is the leading cause of death in the United States, where more than 600 000 people die of heart diseases each year. The most common form of heart disease is coronary heart disease (CHD). This primarily involves blockages in one or more of the arteries that supply oxygen to the heart. Depending on their severity and location, these blockages may lead to a myocardial infarction (heart attack). Many factors contribute to the development of heart disease. Some are risk factors that can be treated with medical intervention. Several of the risk factors for heart disease can be prevented by lifestyle changes.