Description

Acute decompensated heart failure (ADHF) is a heterogenous group of related syndromes with new-onset or recurrence of cardiac pump function impairment. This leads to a wide variety of symptoms that are secondary to pulmonary congestion with elevated left atrial pressure, excessive fluid accumulation and reduction in cardiac output. ADHF can be a new diagnosis or represent worsening of preexisting chronic heart failure (HF). A number of terms have been used to describe this pathology including acute HF, acute HF syndrome, as well as acute decompensation of chronic HF.

Epidemiology

• HF is a growing health care concern with regard to morbidity and mortality. HF hospitalization places a major strain on health care resources, and Medicare spends more to diagnose and treat HF than any other medical condition. HF is the most common cause of admission and readmission in the United States in those >65 years of age, responsible for more than 1 million annual hospitalizations. In 2012, the total cost of HF was $30.7 billion. By 2030, the total cost will increase 127% to $69.7 billion. The majority of costs (approximately 2/3) are attributed to the management of ADHF episodes. HF is the primary cause of >55,000 deaths each year and a contributing factor in >280,000 deaths.
• >1 million hospital discharges per year, unchanged from 2000 to 2010, and about half of people who have HF die within 5 years of diagnosis. One in nine deaths has HF mentioned on the death certificate.
• The average 1-year mortality rates for first hospitalized ADHF patients range from 20% to 30%.
• The age-adjusted risk for all-cause mortality in patients with HF has tripled when compared to patients without HF.

• ~6.5 million people age >20 years in the United States carry an HF diagnosis; prevalence is expected to increase 46% from 2012 to 2030, resulting in >8.4 million cases in patients >18 years of age.
• HF is primarily a disease of the elderly; 75% of hospital admissions for HF are in persons >65 years of age.
• African Americans have the highest risk of developing HF, followed by Hispanics, whites, and Chinese Americans, which reflects differences in the prevalence of hypertension (HTN), diabetes mellitus, atrial fibrillation, obesity, and socioeconomic status.

Etiology and Pathophysiology

• Two potential pathophysiologic conditions lead to the clinical findings of HF, namely systolic and/or diastolic heart dysfunction.
  • Systolic dysfunction: an inotropic abnormality, due to myocardial infarction (MI) or dilated or ischemic cardiomyopathy (CM), resulting in diminished systolic emptying (ejection fraction <45%)
  • Diastolic dysfunction: a compliance abnormality, due to hypertensive CM, in which ventricular relaxation is impaired (ejection fraction >45%), resulting in decreased filling
  • In an attempt to adopt a more pragmatic classification system, one that has been accepted by both the European and American HF guidelines, the terms HF with reduced, midrange, or preserved LVEF (HFrEF, HFmrEF, and HFpEF, respectively) have been adopted recently.
  • Recent American HF guidelines have also described three clinical profiles of patients with ADHF that take into account the patient's clinical manifestations, hemodynamics, and systemic perfusion:
    • Patients with volume overload: evidenced by pulmonary and/or systemic congestion and often triggered by an acute hypertensive crisis
    • Patients with depression of cardiac output: evidenced by hypotension, renal hypoperfusion, and/or shock
    • Patients with signs and symptoms of both volume overload and shock
• ADHF can result from the following conditions:
  • Myocardial disease:
    • Exacerbation of preexisting chronic HF heralded by noncompliance or infection or some other acute trigger
    • Any of the following as causes of new HF or exacerbation of preexisting chronic HF: coronary artery disease (CAD), MI, toxic damage, immune-mediated and inflammatory damage, infiltrative diseases, metabolic derangements, and genetic abnormalities
• Abnormal loading conditions:
  • HTN, valvular and myocardial structural defects, pericardial and endomyocardial pathologies, high-output states, volume overload
• Arrhythmias:
  • Atrial fibrillation, tachyarrhythmias, high-grade heart block, bradyarrhythmias

Genetics
Familial CM is a predisposition to the development of HF (rare).

Risk Factors

CAD and MI; diabetes mellitus; cigarette smoking; valvular heart disease; HTN, systemic or pulmonary; dietary sodium intake; obesity

General Prevention

Mortality reduction has been attributed to treating HF risk factors (see above), with the implementation of ACE inhibitors, β-blockers, coronary revascularization, implantable cardioverter-defibrillators, and cardiac resynchronization strategies in patients.

• Some recommend B-type natriuretic peptide (BNP) screening in conjunction with guideline-directed management/therapies (GDMT) for at-risk populations to aid in the prevention of new-onset HF and to delay development of left ventricular (LV) dysfunction in existing HF.
• GDMT includes clinical evaluation, diagnostic testing, pharmacologic and procedural treatments, along with management of comorbidities, medication reconciliation, laboratory testing, and patient education programs. This integrated approach is crucial for disease prevention and in decreasing hospitalization.

Commonly Associated Conditions

• Dysrhythmia followed by pump failure is the leading cause of death in ADHF. Most patients have >5 comorbidities (especially CAD, chronic kidney disease, and diabetes) and take >5 medications.
• Cardiogenic shock