LAUSR

The heart failure population is ever expanding, with approximately 23 million people worldwide diagnosed with heart failure (HF). In the United States, acute HF (AHF) accounts for more than 1 million hospital admissions.1–3 Despite improvements in morbidity and mortality for patients with chronic HF with reduced ejection fraction (EF) due to pharmacological and device-based therapies, rates of admission, readmission, and mortality remain high. Overall, in-hospital mortality is relatively low; it is the early postdischarge period, termed the “vulnerable phase” (VP), where the greatest number of adverse outcomes occurs (Figure 1). The VP begins with an AHF exacerbation and lasts up to 6 months postdischarge. Patients who survive this 6-month period after AHF represent a uniform cohort without significant variability among clinical profiles or systolic blood pressure classifications at the time of admission, thus suggesting an end point for the VP.4 This VP period is associated with an increased risk of readmission and mortality, with rates of 30% and 10%, respectively, within the first few weeks.5 Such poor outcomes may be attributed to cardiac factors (such as myocardial infarctions, atrial fibrillation, and uncontrolled hypertension), noncardiac comorbidities (such as diabetes, chronic obstructive pulmonary disease, and infection), patient-related factors (medication nonadherence, alcohol and substance abuse, dietary indiscretions), and system-based factors (such as poor access to discharge follow up).6 Additionally, the VP can be further categorized into 3 overlapping subphases: early, middle, and late phases. The very early VP includes the acute exacerbation and lasts upto the first few days after discharge. This was evident in the European Society of Cardiology Heart Failure Long-Term registry where 49% of patients admitted in cardiogenic shock died within the first 24 hours following presentation, illustrating the importance of early identification of hypoperfusion and appropriate in-hospital triage of these high risk patients.4 The early VP begins at the moment of discharge, and readmissions during this time frame have been attributed to both patientand system-related factors. The later VP takes into account all precipitating factors and comorbidities within 6 months of discharge7 (Table 1). As time progresses following a AHF, the readmission and mortality rates gradually decline, as highlighted in the Candesartan in Heart Failure: Assessment of Reduction on Mortality and Morbidity trial. Odds for mortality declined from 6-fold during the first month after discharge to 2-fold over the time of the trial.8 The susceptibility of patients during the VP presents a potential opportunity to improve patient outcomes by altering the trajectory of an otherwise poor prognosis.9