What is Stage A Congestive Heart Failure (CHF)?

Stage A Congestive Heart Failure

Stage A CHF represents patients who are at high risk for developing heart failure but have no structural heart disease, no symptoms of heart failure, and no cardiac biomarkers indicating stretch or injury. 1, 2

Defining Characteristics

Stage A patients have identifiable risk factors for heart failure but have not yet crossed the threshold into structural cardiac abnormalities. The key distinction is that these patients have risk factors only—no structural heart disease whatsoever. 1, 3

Risk Factors That Define Stage A

Patients fall into Stage A if they have any of the following conditions:

• Hypertension 1, 2
• Atherosclerotic cardiovascular disease (coronary artery disease) 1, 2
• Diabetes mellitus 1, 2
• Metabolic syndrome 1, 2
• Obesity 1, 2
• Exposure to cardiotoxic agents (chemotherapy drugs) 1, 2
• Genetic variants for cardiomyopathy or positive family history of cardiomyopathy 1, 2
• Chronic kidney disease 4

Clinical Significance and Disease Progression

Stage A represents the earliest opportunity for intervention to prevent heart failure entirely. 1, 3 The ACC/AHA staging system was deliberately designed to mirror cancer staging, where patients advance through stages but cannot spontaneously regress. 3, 5 Once a patient develops structural heart disease (left ventricular hypertrophy, reduced ejection fraction, wall motion abnormalities), they progress to Stage B and cannot return to Stage A, even if asymptomatic. 3

Population Burden

Over 75 million people—approximately 1 in 3 US adults—have Stage A heart failure. 4 The mean age is 56.9 years, with 51.5% being women. 4 This massive at-risk population represents a critical public health opportunity for primordial prevention. 6

Management Approach for Stage A

The primary goal is aggressive risk factor modification to prevent progression to structural heart disease (Stage B) and symptomatic heart failure (Stage C). 1, 2

Specific Interventions

• Blood pressure control: Intensive blood pressure lowering to prevent left ventricular hypertrophy and remodeling 2, 6
• Glycemic control: Adequate diabetes management with target HbA1c <7% 2, 4
• Lipid management: Control dyslipidemia to reduce atherosclerotic burden 2, 6
• Smoking cessation 2
• Alcohol moderation 2
• Regular exercise (though exercise alone is Class III—not recommended as sole prevention strategy) 1, 2
• Weight management: Address obesity, as 49.2% of Stage A patients are obese 2, 4
• Sodium restriction: Limit to <2g/day (72% of Stage A patients consume ≥2g sodium daily) 4
• Avoid cardiotoxic agents when possible 2

Pharmacologic Considerations

ACE inhibitors or ARBs are recommended for appropriate Stage A patients (those with hypertension, diabetes, or atherosclerotic disease requiring these agents for their primary conditions). 1, 2 However, these medications are prescribed for the underlying risk factors themselves, not specifically for heart failure prevention at this stage.

Common Pitfalls in Stage A Recognition

Stage A heart failure is inadequately recognized in clinical practice. 4 Many clinicians fail to identify these patients as being on the heart failure continuum, missing the opportunity for intensive preventive interventions. 7

Gaps in Current Management

Among Stage A patients with specific risk factors, guideline-directed targets are frequently not achieved:

• 30.8% of hypertensive patients have uncontrolled blood pressure (systolic BP ≥140 or diastolic BP ≥90 mmHg) 4
• 43.6% of diabetic patients have HbA1c ≥7%, with Mexican Americans at higher risk for poor control 4
• Having health insurance is strongly associated with better blood pressure and lipid control, highlighting socioeconomic barriers to prevention 4

Risk-Enhancing Factors Requiring Recognition

Beyond traditional risk factors, identify these conditions that markedly increase heart failure risk:

• Atrial fibrillation 6
• Chronic kidney disease 6
• Chronic inflammatory diseases 6
• Sleep-disordered breathing 6
• Adverse pregnancy outcomes 6
• History of radiation therapy 6
• Prior cardiotoxic chemotherapy exposure 6
• COVID-19 infection 6

Diagnostic Approach

Routine screening for left ventricular dysfunction in asymptomatic Stage A patients without structural heart disease is Class III (not recommended). 1 However, noninvasive evaluation of left ventricular function is reasonable (Class IIa) in patients with:

• Strong family history of cardiomyopathy 1
• Those receiving cardiotoxic interventions (chemotherapy) 1

Early use of biomarkers (BNP, NT-proBNP, troponin) and echocardiography may enhance risk prediction in select high-risk individuals to detect subclinical dysfunction before symptoms develop. 6

Key Distinction from Stage B

The critical threshold between Stage A and Stage B is the presence of structural heart disease. 3, 5 Stage A patients have normal cardiac structure and function despite risk factors. Once any structural abnormality develops—left ventricular hypertrophy, reduced ejection fraction, chamber enlargement, wall motion abnormalities, valvular disease, or elevated filling pressures—the patient has crossed into Stage B and requires different, more intensive pharmacologic interventions (ACE inhibitors/ARBs and beta-blockers with Class I evidence for heart failure prevention). 3, 5