Patients were excluded if they were in cardiogenic shock (defined as systolic blood pressure of less than 80 mm Hg for more than 30 minutes or the need for intravenous pressors or intraaortic-balloon counterpulsation); had a history of bleeding diathesis; had a history of leukopenia, thrombocytopenia, or severe hepatic or renal dysfunction; had a noncardiac illness associated with a life expectancy of less than one year; were participating in another study; or were unable to give informed consent owing to prolonged cardiopulmonary resuscitation.