What are the recommended tests and evaluations to diagnose heart failure?

Comprehensive Diagnostic Approach to Heart Failure

The diagnosis of heart failure requires a combination of clinical assessment, laboratory testing, and cardiac imaging, with echocardiography being the gold standard for confirming cardiac dysfunction. 1

Initial Diagnostic Evaluation

Clinical Assessment

• Symptoms: Evaluate for dyspnea (at rest or with exertion), fatigue, and fluid retention symptoms
• Signs: Look for pulmonary rales, peripheral edema, elevated jugular venous pressure, displaced cardiac apex, and third heart sound (S3)

Essential First-Line Tests

1. 12-lead ECG - Recommended in all patients to determine heart rhythm, rate, QRS morphology, and duration 1

   • Note: A normal ECG has >90% negative predictive value for excluding LV systolic dysfunction 1

2. Chest X-ray - Recommended to detect:

   • Cardiomegaly
   • Pulmonary congestion/edema
   • Alternative pulmonary causes of dyspnea 1

3. Laboratory tests:

   • Blood counts: Hemoglobin and WBC
   • Electrolytes: Sodium, potassium
   • Renal function: Urea, creatinine with estimated GFR
   • Liver function: Bilirubin, AST, ALT, GGTP
   • Metabolic parameters: Glucose, HbA1c
   • Thyroid function: TSH
   • Iron studies: Ferritin, transferrin saturation 1

4. Natriuretic peptides (BNP or NT-proBNP):

   • Should be considered to support clinical decision-making, especially when diagnosis is uncertain
   • Particularly useful as a "rule out" test due to high negative predictive value 1

Cardiac Imaging

Echocardiography

• Primary imaging modality for heart failure diagnosis 1
• Provides critical information on:
  • Left ventricular ejection fraction (LVEF) - distinguishes between HFrEF, HFmrEF, and HFpEF
  • Chamber sizes and wall thickness
  • Valvular function
  • Diastolic function
  • Regional wall motion abnormalities
  • Pericardial disease 1

Additional Imaging Based on Clinical Context

• Cardiac MRI: Consider for specific etiologies (myocarditis, infiltrative diseases, congenital abnormalities)
• Cardiac CT: May be considered in patients with low to intermediate pre-test probability of CAD or equivocal non-invasive stress tests 1
• Nuclear imaging: Consider for viability assessment and ischemia evaluation

Coronary Artery Disease Assessment

• Coronary angiography: Recommended in patients with HF and angina, history of cardiac arrest, or ventricular arrhythmias 1
• Non-invasive stress testing: Consider in patients with intermediate pre-test probability of CAD

Specialized Testing in Selected Patients

1. Cardiopulmonary exercise testing:

   • Recommended for heart transplantation or mechanical circulatory support evaluation
   • Useful for identifying causes of unexplained dyspnea
   • Helps optimize exercise training prescription 1

2. Right heart catheterization:

   • Recommended in patients with severe HF being evaluated for heart transplantation
   • Consider for assessing pulmonary hypertension before valve/structural heart disease correction
   • May be considered in patients with refractory symptoms despite standard therapy 1

3. Endomyocardial biopsy:

   • Consider in patients with rapidly progressive HF despite standard therapy when specific diagnoses are suspected 1

Follow-up Assessment

Reassessment of cardiac structure and function using non-invasive imaging is recommended:

• When HF symptoms worsen
• After acute cardiovascular events
• Before device implantation decisions (ICD, CRT)
• In patients exposed to cardiotoxic therapies 1

Common Pitfalls to Avoid

1. Relying solely on symptoms - Heart failure is a clinical syndrome requiring objective evidence of cardiac dysfunction
2. Overlooking diastolic dysfunction - Up to 40-50% of HF patients have preserved ejection fraction 2
3. Missing alternative diagnoses - Conditions like COPD, anemia, or thyroid disease can mimic HF symptoms
4. Underutilizing natriuretic peptides - These biomarkers have excellent negative predictive value
5. Failing to identify the underlying etiology - Treatment strategies depend on identifying and addressing the cause of HF

By following this systematic diagnostic approach, clinicians can accurately diagnose heart failure, determine its etiology, assess its severity, and guide appropriate therapy to improve patient outcomes.