Heart Failure (Congestive Heart Failure)

Excerpt

Heart failure (HF), as defined by the American College of Cardiology (ACC) and the American Heart Association (AHA), is a complex clinical syndrome that results from any structural or functional impairment of ventricular filling or ejection of blood. HF is a common disorder worldwide with a high morbidity and mortality rate. With an estimated prevalence of 26 million people worldwide, CHF contributes to increased healthcare costs, reduces functional capacity, and significantly affects quality of life. Accurately diagnosing and effectively treating the disease is essential to prevent recurrent hospitalizations, decrease morbidity and mortality, and enhance patient outcomes.

The etiology of HF is variable and extensive. Ischemic heart disease is the leading cause of HF. The general management of HF aims to relieve systemic and pulmonary congestion and stabilize hemodynamic status, regardless of the cause. The treatment of HF requires a multifaceted approach involving patient education, optimal medication administration, and decreasing acute exacerbations. Per the recent ACC/AHA guidelines for HF 2022, patients with HF are classified based on left ventricle ejection fraction (LVEF), whereas clinical and laboratory parameters are integrated to stage patients. The New York Heart Association (NYHA) classification stratifies and defines the functional capacity and severity of HF symptoms. This system is subjectively determined by clinicians and is widely used in clinical practice to direct therapy. Management of patients depends on the classification and staging of the disease.

The following parameters are used to classify HF based on LVEF:

1. HF with reduced ejection fraction (HFrEF): LV EF ≤40%

2. HF with mildly reduced ejection fraction: LVEF 41% to 49% and evidence of HF (spontaneous or provokable elevated cardiac biomarkers or elevated filling pressures)

3. HF with preserved ejection fraction (HFpEF): LVEF ≥50% and evidence of HF (spontaneous or provokable elevated cardiac biomarkers or elevated filling pressures)

4. HF with improved ejection fraction: LV EF >40%, with previously documented LV EF ≤40%

The ACC/AHA Stages of HF are as follows:

1. Stage A: At risk for HF. No current or past symptoms, structural heart disease, or evidence of elevated cardiac biomarkers, but risk factors are present. Risk factors include hypertension, diabetes, metabolic syndrome, cardiotoxic medications, or having a genetic variant for cardiomyopathy.

2. Stage B: Pre-HF. Patients have no signs or symptoms of HF but have risk factors and structural heart disease, evidence of elevated filling pressures (by invasive or noninvasive assessment), or persistently elevated cardiomarkers in the absence of other reasons for elevated markers, like chronic kidney disease or myocarditis.

3. Stage C: Symptomatic HF. Patients with current or past history of HF symptoms.

4. Stage D: Advanced HF. Patients with refractory symptoms that interfere with daily life or recurrent hospitalization despite targeted guideline-directed medical therapy.

For stage C and stage D HF patients, the following NYHA classification of HF symptoms should be used:

1. Class I: Symptom onset with more than ordinary level of activity

2. Class II: Symptom onset with an ordinary level of activity

3. Class III: Symptom onset with minimal activity

4. 1. Class III a: No dyspnea at rest

   2. Class III b: Recent onset of dyspnea at rest

5. Class IV: Symptoms at rest