CHAPTER SUMMARY AND CENTRAL ILLUSTRATION
This chapter discusses the epidemiology, pathophysiology, evaluation, and management of acute heart failure (AHF), which is the onset or recurrence of symptoms and signs of heart failure requiring urgent or emergent therapy. The pathophysiology of AHF is complex, incorporating cardiac dysfunction, neurohormonal activation and inflammation, renal dysfunction, and vascular and endothelial dysfunction (see Fuster and Hurst's Central Illustration). The interplay of these systems ultimately leads to signs and symptoms related to congestion, hypoperfusion, or both. The evaluation of the patient with AHF requires rapidly establishing the diagnosis, treating potentially life-threatening presentations such as shock or respiratory failure, identifying triggers or precipitating factors requiring specific treatment such as acute coronary syndrome, risk stratifying to provide the appropriate level of care, and defining the hemodynamic profile to implement appropriate therapy. Management involves relieving congestion and restoring or maintaining perfusion primarily with diuretics and vasodilators. In patients with decreased cardiac output with organ hypoperfusion, inotropes and vasopressors may be needed. Escalation of therapy to mechanical circulatory support may be needed for patients with cardiogenic shock. Transitioning care from the inpatient setting to the outpatient setting is a vulnerable period for patients with AHF and postdischarge follow-up is imperative.
eFig 50-01 Chapter 50: Evaluation and Management of Acute Heart Failure
EPIDEMIOLOGY OF ACUTE HEART FAILURE
The clinical syndrome of heart failure (HF) is defined as current or prior symptoms and/or signs of congestion in the setting of a structural and/or functional cardiac abnormality, corroborated by elevated natriuretic peptide levels or objective evidence by imaging or hemodynamic assessment.1 Acute heart failure (AHF) therefore relates to the onset or recurrence of symptoms and signs of HF requiring urgent or emergent therapy, and resulting in unscheduled care or hospitalization. Although the word “acute” suggests a sudden onset, many patients have a more subacute course, with gradual worsening of symptoms that ultimately reach a level of severity sufficient to seek unscheduled medical care.
AHF is among the most common causes for hospitalization in patients older than age 65. In the United States, 4 million people are hospitalized each year with a primary (1 million) or secondary diagnosis of HF (3 million), the latter highlighting the prevalence of comorbid conditions in patients with HF.2 With an increasing aging population, improvement in medical and device-based therapies resulting in increased survival after myocardial infarction as well as prevention of sudden death, the prevalence of HF is only expected to increase with time. In the United States alone, the costs associated with management of HF approach 40 billion dollars annually, with the majority of expenditures related to the costs of hospitalizations.3,4 Therefore, in efforts to reduce hospitalizations and associated costs, initiatives such as outpatient diuretic clinics ...