Heart Failure Classification and Management

Introduction to Heart Failure Classification

The American College of Cardiology recommends using two distinct but complementary systems to classify heart failure: the ACC/AHA staging system (Stages A-D) and the NYHA functional classification (Classes I-IV) 1

The ACC/AHA staging system reflects the progressive nature of heart failure, and patients typically advance forward through stages without reversal, even when symptoms improve with treatment 1, 2
Stage A: At risk for heart failure, with no structural heart disease, no symptoms, and no elevated biomarkers, and includes patients with risk factors such as hypertension, diabetes, coronary artery disease, or family history of cardiomyopathy 1
Stage B: Pre-heart failure, with structural heart disease but no current or previous symptoms, and evidence of elevated natriuretic peptides, cardiac troponin, or increased filling pressures 1
Stage C: Symptomatic heart failure, with structural heart disease and current or previous symptoms, and patients remain Stage C even if symptoms resolve with treatment 1
Stage D: Advanced heart failure, with marked symptoms that interfere with daily life and recurrent hospitalizations despite optimal guideline-directed medical therapy, and requires evaluation for advanced therapies 1, 3

The NYHA functional classification assesses current symptom severity and can change frequently in response to treatment or disease progression, and is subjective and determined by clinician assessment 1, 2, 4
NYHA Class I: No limitation of physical activity, with ordinary physical activity not causing symptoms of heart failure 4, 5
NYHA Class II: Slight limitation of physical activity, with comfortable rest but ordinary physical activity resulting in symptoms 4, 5
NYHA Class III: Marked limitation of physical activity, with less than ordinary activity causing symptoms 4, 5
NYHA Class IV: Symptoms at rest, with inability to carry on any physical activity without symptoms 4, 5

LVEF classification is critical because it determines prognosis and guides treatment selection, with most clinical trials enrolling patients based on ejection fraction 1
HFrEF: Heart failure with reduced ejection fraction, with LVEF ≤40% 1
HFmrEF: Heart failure with mildly reduced ejection fraction, with LVEF 41-49% 1
HFpEF: Heart failure with preserved ejection fraction, with LVEF ≥50% 1

Always measure ejection fraction to determine if symptoms are due to systolic dysfunction or another cause 5, 7
For HFmrEF and HFpEF diagnosis, additional objective measures beyond symptoms and LVEF are required (elevated natriuretic peptides, evidence of elevated filling pressures, structural abnormalities) 1
All patients with HFrEF should receive guideline-directed medical therapy (ACE inhibitors/ARBs, beta-blockers, mineralocorticoid receptor antagonists) regardless of NYHA class 3, 6
The NYHA classification determines eligibility for certain interventions but should be supplemented with objective measures (NT-proBNP, 6-minute walk distance, quality of life scores, cardiopulmonary exercise testing) 3, 6