Hospitalization epidemic in patients with heart failure: risk factors, risk prediction, knowledge gaps, and future directions

Patients with heart failure (HF) are hospitalized over a million times annually in the United States. Hospitalization marks a fundamental change in the natural history of HF, leading to frequent subsequent rehospitalizations and a significantly higher mortality compared with nonhospitalized patients. Three-fourths of all HF hospitalizations are due to exacerbation of symptoms in patients with known HF. One-half of hospitalized HF patients experience readmission within 6 months. Preventing HF hospitalization and rehospitalization is important to improve patient outcomes and curb health care costs. To implement cost-effective strategies to contain the HF hospitalization epidemic, optimal schemes to identify high-risk individuals are needed. In this review, we describe the risk factors that have been associated with hospitalization risk in HF and the various multimarker risk prediction schemes developed to predict HF rehospitalization. We comment on areas that represent gaps in our knowledge or difficulties in interpretation of the current literature, representing opportunities for future research. We also discuss issues with using HF readmission rate as a quality indicator.