Heart failure (HF) causes substantial morbidity and mortality in the United States and is the most common principal discharge diagnosis in adults aged 65 years and older.^1,2 and ³ Altogether, the costs for HF hospitalizations are approximately $14.7 billion per year.⁴ A substantial number of these patients present to the emergency department for the initial treatment of their acute decompensation. It has been suggested that 80% of all patients who present with acute decompensated heart failure (ADHF) are admitted to the hospital.⁵ Identifying patients who are suitable for discharge home or for admission to an observation unit (OU) may substantially reduce overall hospital costs. However, for emergency physicians, accurate disposition is a challenge and perhaps more daunting than the management of these patients.

Disposition decisions are often time-dependent and lack adequate time to assess response to treatment. This may result in inappropriate admissions and premature emergency department (ED) discharges, with resultant increased cost and morbidity, respectively.^6,7 Although the American College of Cardiology (ACC)/American Heart Association (AHA) guidelines on the management of HF suggest that patients with mild to moderate symptoms generally do not require admission, risk assessment based on symptoms is often difficult.⁵ To increase the number of patients discharged to home, effective treatment must be initiated in the ED as part of their ED management or an OU protocol. This early intervention and avoidance of hospital admission can result in significant cost savings, because 75% of costs arising from hospitalization for HF are incurred within the first 48 hours.⁴

Success of any protocol is dependent on accurate identification of patients suitable for an early discharge plan. Patients with a high probability of adverse outcome, such as those with evidence of acute cardiac ischemia, should be admitted to the hospital as in-patients. Blood pressure and heart rate are two of the most significant independent predictors of acute
mortality in patients with ADHF;⁸ thus, patients with unstable vital signs, including a heart rate greater than 130 beats per minute, systolic blood pressure (SBP) less than 85 mm Hg or greater than 175 mm Hg after initial ED treatment, and O₂ saturation less than 90%, are inappropriate for an early discharge strategy.⁹ In addition, patients with airway instability, inadequate systemic perfusion, or cardiac arrhythmias requiring continuous intravenous (IV) intervention, as well as those requiring invasive hemodynamic monitoring or receiving medications that require frequent uptitration, such as nitroglycerin, are also not suitable for an HF OU admission.⁹

As essential as the identification of appropriate patients for this rapid treatment protocol is, use of discharge criteria to result in a low rate of subsequent hospital readmission soon after discharge is also important. Unfortunately, there is a paucity of data addressing this issue in the ED, in-patient, and OU settings. Current methods of risk stratification have focused on identifying patients at risk for short- and long-term adverse events. Risk stratification is an ongoing process. It is dependent on clinical appearance, laboratory parameters, and response to acute therapies. Discharge to home should be considered from the perspective of an estimate of the acuity of the initial presentation of the patient, improvement in response to treatment, and risk of recidivism after discharge. It is suggested that certain clinical features should then alter the physician’s initial acuity estimate and improvement in these parameters can identify patients suitable for discharge to home.

Consensus guidelines for discharge from the ED and OU have been developed.¹⁰ These guidelines are based on the presence of factors associated with increased risk for adverse events. Although the absence of these parameters does not ensure that a patient is ready for discharge, they are useful in identifying patients with persistent decompensated HF who would benefit from additional treatment. These discharge criteria can be divided into three categories: patient-centered measures, hemodynamic and clinical parameters, and laboratory results (Table 9-1).

It has been well established that patient-centered outcome measures, such as a change in dyspnea, can be used to assess therapeutic success and improvement in symptoms. Although subjective, the measurement of dyspnea on a seven-point or three-point scale is a validated outcome measure.¹¹ In addition, the assessment of dyspnea has been shown to correlate with hemodynamic status in clinical trials. However, no study has evaluated this as an endpoint in an ED or OU, although it continues to be assessed in informal manners.¹¹ Another patient-centered measure that should be present at the time of discharge is the lack of ongoing chest pain. It has been reported that acute coronary syndrome (ACS) is a trigger for up to 25% of HF decompensation. Therefore, patients should be pain free or have undergone an evaluation for ACS prior to discharge.¹² Finally, the patient should be able to ambulate without an increase in dyspnea from baseline. Although no trial has assessed this measure in an OU setting, it effectively is an inexpensive 6-minute exercise test. The distance that
a patient can ambulate in a 6-minute period without excessive dyspnea and fatigue has been shown to correlate with long-term mortality. Unfortunately, many comorbid illnesses, such as obesity and lung disease, affect this outcome measure; hence, it is important to assess a change from baseline.¹³ In addition, freedom from symptoms of congestion such as orthopnea has also been associated with improved long-term outcomes.¹⁴