Signs of acute coronary artery disease lead to nearly 1.5 million hospital admissions each year in the United States. These patients have either angina (chest pain) or myocardial infarction (MI), which is commonly called a heart attack. At the hospital, they routinely receive medical treatments, including blood thinners to prevent blood clots. Doctors may choose conservative management, which means simply watching the patient closely and performing a stress test, or an early invasive approach, which calls for angiography shortly after admission. This x-ray examination shows whether there are significant blockages in the coronary arteries. If necessary, coronary intervention or surgery can be done to restore adequate blood flow to the heart wall. A majority of patients are 65 years of age or older. They tend to have invasive treatment less often than younger patients. Whether invasive measures improve the outlook for elderly patients remains uncertain.