Heart failure is the leading cause of hospitalization among adults 65 years of age in the United States. Annually, 1 million patients are hospitalized with a primary diagnosis of heart failure, accounting for a total Medicare expenditure exceeding $17 billion. 1 Despite dramatic improvement in outcomes with medical therapy, 2, 3 admission rates following heart failure hospitalization remain high, 4 with 50% patients readmitted to hospital within 6 months of discharge. 5–7 Because reduction in readmission rates might simultaneously reduce costs and improve quality of care, public and private payers have increasingly targeted readmissions as a focus of pay-for-performance initiatives. 8 In 2009, the US Center for Medicare & Medicaid Services began public reporting of all-cause readmission rates after heart failure hospitalization, and, in the following year, the Patient Protection and Affordable Care Act9 established financial penalties for hospitals with the highest readmission rates during the first 30 days after discharge. Increasing concern regarding the need to reduce readmissions has focused national research and hospital-driven efforts on the prediction of which patients with heart failure are likely to be readmitted and the design of interventions to prevent readmissions.