The development of heart failure and/or left ventricular systolic dysfunction (LVSD) in the setting of acute myocardial infarction (AMI) results in significant risk far above that of AMI independently. In patients admitted to the hospital for AMI, concomitant heart failure and/or LVSD on hospital admission or development of either or both of these conditions during admission are among the strongest predictors of inhospital death and are associated with significant increases in inhospital, 30-day, and long-term mortality and rehospitalization rates. Given the high risks in this population, aggressive treatment, comprising early initiation and sustained use of evidence-based treatments, is essential for improving prognosis.