Why are so many AHF patients hospitalized? AHF patients have a high post-discharge event rate. Emergency physicians have a low risk tolerance. When both are combined, most patients are admitted. The absence of risk scores for the ED setting compounds the problem. Most risk scores were developed in the hospital. As hospitalization may affect the outcomes of patients, whether these risk scores apply to the ED setting is unknown. As a result, which patients are at lower risk in the ED has not been well-studied. Further, absence of high-risk features does not necessarily equal absolute low morbidity or mortality, though such patients are likely at lower risk. In the absence of a risk score, clinical judgment is a poor substitute and often fails to identify patients at high risk, such that those discharged from the ED may be at equal or greater risk for death than hospitalized patients. Thus, the difficulty of identifying low risk, combined with the inherent high morbidity and mortality of AHF, leads to a disproportionate number of hospitalizations.