What is the early stage of heart failure?

Early Stages of Heart Failure

The early stage of heart failure is classified as Stage A, which includes patients who have risk factors for developing heart failure but do not yet have structural heart disease or symptoms of heart failure. 1

Classification of Heart Failure Stages

The American College of Cardiology Foundation/American Heart Association (ACCF/AHA) developed a staging system for heart failure that emphasizes both the development and progression of the disease:

1. Stage A (Early Stage)

   • Patients at high risk for developing heart failure
   • No structural heart disease or symptoms
   • Risk factors include:
     • Hypertension
     • Coronary artery disease
     • Diabetes mellitus
     • Metabolic syndrome
     • Exposure to cardiotoxic agents
     • Family history of cardiomyopathy 1, 2

2. Stage B

   • Structural heart disease present
   • No symptoms of heart failure
   • Examples include:
     • Left ventricular hypertrophy (LVH)
     • Previous myocardial infarction
     • Asymptomatic valvular disease
     • Reduced left ventricular ejection fraction without symptoms 1

3. Stage C

   • Structural heart disease with current or previous symptoms of heart failure
   • Bulk of patients with heart failure 1

4. Stage D

   • Refractory heart failure requiring specialized interventions
   • Candidates for advanced treatments like mechanical support, transplantation, or end-of-life care 1

Characteristics of Stage A Heart Failure

Stage A represents a critical opportunity for prevention:

• No symptoms of heart failure
• No structural abnormalities of the heart
• Presence of modifiable risk factors that predispose to heart failure development
• May have non-traditional cardiovascular risk factors such as:
  • Atrial fibrillation
  • Chronic kidney disease
  • Chronic inflammatory disease
  • Sleep-disordered breathing
  • History of cardiotoxic chemotherapy exposure 3

Management of Stage A Heart Failure

Treatment at this stage focuses on risk factor modification:

• Management of hypertension and hyperlipidemia is crucial 1
• Lifestyle modifications including:
  • Smoking cessation
  • Regular physical activity
  • Healthy diet
  • Weight management
  • Limiting alcohol consumption 2, 3
• Early identification and treatment of diabetes
• Avoidance of cardiotoxic agents when possible 2

Progression and Monitoring

The staging system recognizes that heart failure is a progressive condition:

• Patients typically advance from one stage to the next unless progression is slowed by treatment
• Spontaneous reversal of progression is unusual
• Early detection using biomarkers (like BNP or NT-proBNP) and imaging techniques may help identify patients at risk of progression 4
• Newer imaging techniques like speckle-tracking echocardiography can detect subclinical cardiac dysfunction before ejection fraction decreases 4

Clinical Importance of Early Identification

Identifying patients in Stage A is critical because:

• Therapeutic interventions before the appearance of left ventricular dysfunction or symptoms can reduce morbidity and mortality 1
• The NYHA functional classification (which measures symptom severity) is only applicable to later stages (C and D)
• Once structural changes occur, the remodeling process can lead to progressive enlargement of the heart and severe dysfunction 5

Pitfalls and Caveats

• Stage A heart failure is often overlooked in clinical practice because patients are asymptomatic
• Risk assessment should be comprehensive, as many patients have different combinations of risk factors with varying absolute risks for heart failure 3
• Left ventricular ejection fraction is normal in early cardiac dysfunction and therefore not a reliable indicator for early detection 4
• Social determinants of health significantly impact risk and should be addressed for effective prevention 3

Understanding and identifying Stage A heart failure represents our best opportunity to prevent the development of symptomatic heart failure and improve long-term outcomes.