Cardiac catheterization and coronary angiography are semi-invasive methods of studying the heart and the blood vessels that supply the heart (coronary arteries) without doing surgery. These tests are usually done when noninvasive tests do not give sufficient information, when noninvasive tests suggest that there is a heart or blood vessel problem, or when a person has symptoms that make a heart or coronary artery problem very likely. One advantage to these tests is that during the test, doctors can also treat various diseases, including coronary artery disease.
More than a million cardiac catheterizations and angiographic procedures are done every year in the United States. They are relatively safe, and complications are rare. With cardiac catheterization and angiography, the chance of a serious complication—such as stroke, heart attack, or death—is 1 in 1,000. Fewer than 0.01% of people undergoing these procedures die, and most of those who die already have a severe heart disorder or other disorder. The risk of complications and death is increased for older people.