Acute coronary syndrome
Acute coronary syndrome (ACS) is a very common and life-threatening result of coronary heart disease, which affects an estimated 17.6 American adults, and results in estimated annual health care costs of $177 billion. ACS conditions, which include acute myocardial infarction and unstable angina, occur when a coronary artery is blocked by a blood clot, reducing the blood supply to the heart. The overall prevalence of ACS in U.S. adults is 3.6%. In 2011, an estimated 785,000 Americans will have a new coronary attack and about 470,000 will have a recurrent attack. In addition, about 195,000 "silent" heart attacks occur each year. Despite available therapies, the risk of illness or death for patients with ACS remains high. Almost 30% of patients who leave the hospital after an ACS event are readmitted within the first 6 months.