What are the diagnostic tests and treatment options for congestive heart failure?

Diagnostic Testing for Congestive Heart Failure

All patients with suspected heart failure require a 12-lead ECG, transthoracic echocardiography to assess left ventricular ejection fraction, and a comprehensive laboratory panel including natriuretic peptides, renal function, and complete blood count as the essential diagnostic workup. 1, 2

Essential First-Line Tests (Class I Recommendations)

Cardiac Imaging

• Transthoracic echocardiography with Doppler is mandatory to determine left ventricular ejection fraction (LVEF), assess cardiac chamber size, wall thickness, regional wall motion abnormalities, and evaluate valve function 1, 2
• This is the definitive test to confirm heart failure and classify it as HFrEF (reduced EF), HFmrEF (mid-range EF), or HFpEF (preserved EF), which directly guides treatment decisions 1, 2

Electrocardiography

• A 12-lead ECG is required in all patients to determine heart rhythm, heart rate, QRS morphology and duration, detect conduction abnormalities, identify left ventricular hypertrophy, and look for evidence of prior myocardial infarction 1, 2
• This information is essential for planning device therapy (ICD, CRT) and monitoring treatment response 1

Laboratory Testing

The following blood tests are mandatory for initial assessment 1, 2:

• Complete blood count (hemoglobin and white blood cells) to detect anemia or infection 1
• Renal function panel: sodium, potassium, urea, creatinine with estimated GFR to assess kidney function and guide medication dosing 1, 2
• Liver function tests: bilirubin, AST, ALT, GGTP to detect hepatic congestion 1
• Metabolic panel: glucose and HbA1c to identify diabetes 1
• Thyroid function: TSH to rule out thyroid disease as a reversible cause 1
• Iron studies: ferritin, transferrin saturation (TSAT), and total iron-binding capacity (TIBC) to detect iron deficiency 1

Natriuretic Peptides

• BNP or NT-proBNP should be measured (Class IIa recommendation) when the diagnosis remains uncertain after initial evaluation, as heart failure is highly unlikely with normal levels 1, 2

Chest Radiography

• Chest X-ray (PA and lateral views) is recommended to detect or exclude alternative pulmonary diseases, identify cardiomegaly, pulmonary venous congestion, interstitial edema, pleural effusions, and Kerley B lines 1, 2
• This is particularly useful in acute heart failure presentations 1

Coronary Artery Disease Assessment

Since coronary artery disease accounts for 75-80% of heart failure cases 3, evaluation for CAD is critical:

• Invasive coronary angiography is mandatory in patients with angina refractory to medical therapy, symptomatic ventricular arrhythmias, or aborted cardiac arrest who are suitable for revascularization 1
• Coronary angiography should be strongly considered in patients with intermediate to high pre-test probability of CAD and evidence of ischemia on non-invasive stress testing 1, 2
• Non-invasive stress imaging (cardiac MRI, stress echocardiography, SPECT, or PET) may be considered to assess myocardial ischemia and viability before revascularization decisions 1

Advanced Imaging When Indicated

Cardiac Magnetic Resonance (CMR)

• CMR with late gadolinium enhancement is recommended when suspecting specific etiologies including myocarditis, amyloidosis, sarcoidosis, Chagas disease, Fabry disease, non-compaction cardiomyopathy, or hemochromatosis 1

Reassessment Imaging

Non-invasive imaging reassessment is required 1:

• When patients develop worsening heart failure symptoms or acute decompensation 1
• Before device implantation (ICD, CRT) after maximizing evidence-based pharmacotherapy 1
• During serial monitoring in patients exposed to cardiotoxic therapies like chemotherapy 1

Specialized Testing in Selected Patients

Exercise Testing

• Cardiopulmonary exercise testing is mandatory for evaluation before heart transplantation or mechanical circulatory support 1
• Should be considered to optimize exercise training prescription and identify causes of unexplained dyspnea 1

Right Heart Catheterization

• Required in severe heart failure being evaluated for transplantation or mechanical support 1
• Should be considered to assess pulmonary hypertension reversibility before valve or structural heart disease correction 1
• May be considered when hemodynamic status is unclear despite standard therapies 1

Endomyocardial Biopsy

• Should be considered in rapidly progressive heart failure despite standard therapy when a specific treatable pathology is suspected 1

Additional Testing for Specific Etiologies

When clinical suspicion exists for particular pathologies 1, 2:

• Hemochromatosis screening (serum ferritin, iron studies)
• HIV testing in at-risk populations
• Rheumatologic panel for inflammatory causes
• Sleep study for suspected sleep apnea
• Troponin I or T if acute coronary syndrome is suspected 2

Critical Pitfalls to Avoid

• Never delay echocardiography—it is the definitive test that confirms diagnosis and guides all subsequent therapy 2
• Do not assume the diagnosis without objective evidence from imaging and laboratory tests 2
• Always search for reversible causes: peripartum cardiomyopathy, viral myocarditis, thyroid disease, alcohol-induced cardiomyopathy, undiagnosed valvular disease, hemochromatosis 2, 4
• Heart failure is highly unlikely if dyspnea is absent and both chest X-ray and ECG are normal 4
• Monitor renal function and electrolytes (especially potassium and magnesium) closely during diuretic therapy 2, 5