Heart Failure and Ejection Fraction

Excerpt

Heart failure (HF) remains a prevailing cause of cardiovascular morbidity and mortality globally despite advancements in therapies and preventive measures. The Centers for Disease Control and Prevention (CDC) estimates that 6.7 million individuals aged 20 or older in the United States are affected by HF. It is anticipated that the prevalence of HF will increase to 8.5 million Americans by 2030.

Definition of Heart Failure

HF is a multifaceted clinical syndrome arising from functional or structural impairment in the filling or ejection of blood by the ventricles, leading to a diverse range of symptoms.

American College of Cardiology/ American Heart Association Stages of Heart Failure

The American College of Cardiology (ACC) and the American Heart Association (AHA) have outlined stages of heart failure to classify the progression and severity of the condition (Table 1. ACC/AHA Stages of Heart Failure).

Patients who have resolved symptoms and signs of HF with persistent left ventricular dysfunction are categorized as stage C and should receive appropriate treatment. If all HF symptoms, signs, and structural abnormalities completely resolve, the patient is deemed to be in remission from HF.

Classification of Heart Failure by Left Ventricular Ejection Fraction

Patients with HF are frequently classified by left ventricular ejection fraction (LVEF). This classification system acknowledges the different prognoses and responses to guideline-directed medical therapy (GDMT) for patients with heart failure. The 2022 AHA/ACC/Heart Failure Society of America (HSFA) Guideline for the Management of Heart Failure identifies 4 classes of HF by LVEF (Table 2. Classification of Heart Failure by Left Ventricular Ejection Fraction).

New York Heart Association Classification of Heart Failure

The NYHA classification of HF is a subjective evaluation by a clinician to delineate the functional capacity and symptoms of individuals diagnosed with ACC/AHA stage C or D heart failure. Serving as an independent predictor of mortality, the NYHA Classification is employed in clinical settings to assess the appropriateness of therapeutic interventions for patients in stage C or D of heart failure. The 4 NYHA heart failure classes are:

1. Class I (Mild HF): No restrictions in physical activity. Ordinary physical activity does not induce undue fatigue, palpitations, or dyspnea.

2. Class II (Mild-to-Moderate HF): Slight limitations in physical activity. Comfortable at rest, but ordinary activities result in fatigue, palpitations, or dyspnea.

3. Class III (Moderate-to-Severe HF): Significant restrictions in physical activity. Comfortable at rest, but less than ordinary activities lead to fatigue, palpitations, or dyspnea.

4. Class IV (Severe HF): Unable to engage in physical activity without discomfort. Symptoms of heart failure are present at rest, and any physical activity exacerbates the discomfort.