<Tr> <Th> Frequency </Th> <Td> 110 million (2015) </Td> </Tr> <Tr> <Th> Deaths </Th> <Td> 8.9 million (2015) </Td> </Tr> <P> Coronary artery disease (CAD), also known as ischemic heart disease (IHD), refers to a group of diseases which includes stable angina, unstable angina, myocardial infarction, and sudden cardiac death . It is within the group of cardiovascular diseases of which it is the most common type . A common symptom is chest pain or discomfort which may travel into the shoulder, arm, back, neck, or jaw . Occasionally it may feel like heartburn . Usually symptoms occur with exercise or emotional stress, last less than a few minutes, and improve with rest . Shortness of breath may also occur and sometimes no symptoms are present . In many cases, the first sign is a heart attack . Other complications include heart failure or an abnormal heartbeat . </P> <P> Risk factors include high blood pressure, smoking, diabetes, lack of exercise, obesity, high blood cholesterol, poor diet, depression, and excessive alcohol . The underlying mechanism involves reduction of blood flow and oxygen to the heart muscle due to atherosclerosis of the arteries of the heart . A number of tests may help with diagnoses including: electrocardiogram, cardiac stress testing, coronary computed tomographic angiography, and coronary angiogram, among others . </P>

What type of disease is coronary heart disease