From the Guidelines
Heart failure is classified into three main categories based on left ventricular ejection fraction (LVEF): Heart Failure with Reduced Ejection Fraction (HFrEF) with an LVEF of 40% or less, Heart Failure with Preserved Ejection Fraction (HFpEF) with an LVEF of 50% or greater, and Heart Failure with Mildly Reduced Ejection Fraction (HFmrEF) with an LVEF between 41-49%.
Classification of Heart Failure
The classification of heart failure based on LVEF is crucial because it influences prognosis, treatment approaches, and response to therapies 1.
- HFrEF is defined as an LVEF of 40% or less, representing systolic dysfunction where the heart cannot contract effectively.
- HFpEF is characterized by an LVEF of 50% or greater, where the heart contracts normally but cannot relax properly, impairing filling.
- HFmrEF includes patients with an LVEF between 41-49%, which is considered an evolving category where some patients may benefit from therapies traditionally used for HFrEF.
Clinical Importance of Classification
This classification is clinically important because treatment approaches differ significantly between categories.
- HFrEF has well-established guideline-directed medical therapies including ACE inhibitors/ARBs, beta-blockers, mineralocorticoid receptor antagonists, and SGLT2 inhibitors that improve mortality.
- HFpEF management focuses more on symptom control and treating underlying conditions like hypertension.
- HFmrEF patients may benefit from therapies traditionally used for HFrEF, but the approach is still evolving.
Regular Assessment of LVEF
Regular echocardiographic assessment of LVEF is essential for proper classification and treatment optimization as a patient's category may change over time with disease progression or improvement 1. The most recent guidelines emphasize the importance of LVEF in classifying heart failure and guiding treatment decisions 1.
From the Research
Classification of Heart Failure based on Left Ventricular Ejection Fraction (LVEF)
- Heart failure (HF) is categorized into three main types based on Left Ventricular Ejection Fraction (LVEF):
Characteristics of Each Category
- HFpEF is a heterogeneous disorder with increasing prevalence in the elderly, and its pathogenesis remains incompletely understood 3
- HFrEF is associated with a higher risk of cardiovascular events compared to HFmrEF and HFpEF 4
- HFmrEF is considered an intermediate clinical entity between HFrEF and HFpEF, with a milder condition than HFrEF but similar to HFrEF in terms of the high prevalence of ischemic heart disease 4, 5
Treatment and Prognosis
- Therapies effective in patients with HFrEF may also be effective in patients with HFmrEF 4, 5
- The risk of non-cardiovascular adverse events is similar or greater in patients with HFmrEF or HFpEF compared to those with HFrEF 4
- LVEF is a continuous variable, and cutpoints are arbitrary, often based on historical clinical trial enrichment decisions rather than physiology 6