The prognosis of congenital or long-term anemia was formerly limited by the complications of blood transfusion, splenectomy, or infection, problems now largely overcome by sophisticated clinical care. Lifespan is now determined by the rate of myocardial iron deposition, with death occurring from cardiac failure or arrhythmia, usually between the ages of 15 and 25. Endocrine complications and hepatic enlargement are also evident by this age. Deferoxamine increases urinary iron excretion and is the only chelator currently available for chronic administration. Daily administration of deferoxamine results in negative iron balance in most patients by the age of 10; this study was designed to determine whether the onset of cardiac complications was delayed and life prolonged by iron removal.