From the Guidelines
Heart failure is classified into several types, including heart failure with reduced ejection fraction (HFrEF), heart failure with preserved ejection fraction (HFpEF), and heart failure with mildly reduced ejection fraction (HFmrEF), as well as by the New York Heart Association (NYHA) functional classification, which categorizes heart failure into four classes (I through IV) based on symptom severity and physical limitations, as outlined in the 2023 ACC expert consensus decision pathway on management of heart failure with preserved ejection fraction 1.
Classification by Ejection Fraction
The most common classification of heart failure is by ejection fraction, which includes:
- Heart failure with reduced ejection fraction (HFrEF), where EF is less than 40%
- Heart failure with preserved ejection fraction (HFpEF), where EF is 50% or greater
- Heart failure with mildly reduced ejection fraction (HFmrEF), where EF is between 41-49%
New York Heart Association (NYHA) Functional Classification
The NYHA functional classification categorizes heart failure into four classes based on symptom severity and physical limitations:
- Class I: No limitation of physical activity
- Class II: Slight limitation of physical activity
- Class III: Marked limitation of physical activity
- Class IV: Unable to perform any physical activity without symptoms of heart failure
Other Classifications
Heart failure can also be classified by:
- Side of the heart affected (left-sided, right-sided, or biventricular)
- Onset (acute or chronic)
- Cardiac output (high-output or low-output)
- Compensated (when symptoms are controlled) or decompensated (when symptoms worsen despite treatment) These classifications help guide treatment approaches, with medications like ACE inhibitors, beta-blockers, and diuretics being prescribed based on the specific type and severity of heart failure, as recommended by the 2023 ACC expert consensus decision pathway on management of heart failure with preserved ejection fraction 1 and the 2024 systematic review of clinical practice guidelines and recommendations for heart failure with preserved ejection fraction management 1.
From the Research
Classifications of Heart Failure
The classifications of heart failure can be understood through various frameworks, including the New York Heart Association (NYHA) classification and the classification based on left ventricular ejection fraction (LVEF).
New York Heart Association (NYHA) Classification: This system categorizes heart failure into four functional classes based on the severity of symptoms and the impact on physical activity 2, 3, 4.
- NYHA Class I: No limitation of physical activity
- NYHA Class II: Slight limitation of physical activity
- NYHA Class III: Marked limitation of physical activity
- NYHA Class IV: Unable to carry on any physical activity without discomfort
Classification Based on Left Ventricular Ejection Fraction (LVEF): This classification system categorizes heart failure based on the LVEF, which is a measure of how well the heart pumps blood 5, 6.
- Heart Failure with Reduced Ejection Fraction (HFrEF): LVEF ≤40%
- Heart Failure with Mildly Reduced Ejection Fraction (HFmrEF): LVEF 41% to 49%
- Heart Failure with Preserved Ejection Fraction (HFpEF): LVEF ≥50%
- Heart Failure with Improved Ejection Fraction (HFimpEF): Baseline LVEF ≤40%, a ≥10-point increase from baseline LVEF, and a second measurement of LVEF of >40%
Stages of Heart Failure
In addition to these classifications, heart failure can also be understood in terms of its stages, which reflect the progression of the disease and the presence of symptoms or signs 5.
- At-risk for Heart Failure (Stage A)
- Pre-Heart Failure (Stage B)
- Heart Failure (Stage C)
- Advanced Heart Failure (Stage D)