What is the initial workup for reduced ejection fraction (REF) congestive heart failure (CHF)?

Initial Workup for Reduced Ejection Fraction Heart Failure

All patients presenting with suspected HFrEF require a comprehensive initial evaluation including complete blood count, comprehensive metabolic panel, lipid profile, thyroid function, liver enzymes, urinalysis, 12-lead ECG, chest X-ray, and two-dimensional echocardiography with Doppler to confirm reduced LVEF and assess cardiac structure. 1

Immediate Clinical Assessment

Volume Status and Hemodynamics:

• Assess jugular venous distension, hepatojugular reflux, peripheral edema (location and severity), pulmonary rales, and presence of S3 gallop 2
• Measure orthostatic blood pressure changes (supine to standing) to evaluate volume status and autonomic function 1, 2
• Document baseline weight, height, and calculate BMI for monitoring treatment response 1, 2

Functional Capacity:

• Quantify dyspnea severity and assess ability to perform routine and desired activities of daily living 1, 2
• Document NYHA functional class (I-IV) based on symptom severity with physical activity 1

Critical History Elements:

• Obtain detailed medication history including chemotherapy exposure (anthracyclines, trastuzumab), alcohol consumption patterns, illicit drug use (cocaine, methamphetamine), and alternative/herbal therapies 1, 2
• Elicit history of chest pain, angina, or ischemic symptoms to guide coronary evaluation 1

Essential Laboratory Testing

Initial Blood Work (All Patients):

• Complete blood count to assess for anemia 1, 2
• Serum electrolytes including sodium, potassium, calcium, and magnesium 1, 2
• Renal function: blood urea nitrogen and serum creatinine 1, 2
• Fasting blood glucose and hemoglobin A1c 1
• Lipid profile (total cholesterol, LDL, HDL, triglycerides) 1
• Liver function tests (AST, ALT, alkaline phosphatase, bilirubin) 1, 2
• Thyroid-stimulating hormone (TSH) 1, 2
• Urinalysis 1, 2

Natriuretic Peptides:

• Measure BNP or NT-proBNP if diagnosis remains uncertain after initial evaluation; a low-normal concentration in an untreated patient makes heart failure unlikely 1, 2

Cardiac Imaging and Diagnostic Studies

Electrocardiogram (Mandatory):

• Perform 12-lead ECG to identify arrhythmias (atrial fibrillation, ventricular arrhythmias), conduction abnormalities (bundle branch blocks, AV blocks), left ventricular hypertrophy, pathological Q-waves suggesting prior myocardial infarction, and QRS duration >120 ms suggesting dyssynchrony 1, 2
• Critical pitfall: A completely normal ECG has >90% negative predictive value for excluding LV systolic dysfunction; if ECG is normal, carefully reconsider the diagnosis 1

Chest Radiograph (PA and Lateral):

• Obtain to assess for cardiomegaly (cardiothoracic ratio >0.5), pulmonary venous congestion, interstitial edema, pleural effusions, and Kerley B lines 1, 2

Echocardiography (Definitive Test):

• Perform two-dimensional echocardiography with Doppler during initial evaluation to assess: 1, 2
  • Left ventricular ejection fraction (LVEF <40% confirms HFrEF)
  • LV size and volumes
  • Wall thickness and regional wall motion abnormalities
  • Valve function (mitral regurgitation, aortic stenosis)
  • Diastolic function parameters
  • Estimated right ventricular systolic pressure and central venous pressure
• Radionuclide ventriculography is an alternative method to assess LVEF if echocardiography is inadequate 1
• Critical pitfall: Do not delay echocardiography—it is the definitive test to confirm diagnosis and guide therapy 2

Coronary Artery Disease Evaluation

Coronary Angiography Indications:

• Mandatory: Perform coronary arteriography in patients with angina or significant ischemia unless patient is not eligible for any revascularization 1
• Reasonable: Consider in patients with chest pain of uncertain cardiac origin who have not had prior coronary evaluation and have no contraindications to revascularization 1
• Reasonable: Consider in patients with known or suspected coronary artery disease even without angina, unless ineligible for revascularization 1

Non-invasive Ischemia Testing:

• Consider stress echocardiography, nuclear perfusion imaging, or cardiac MRI to detect myocardial ischemia and viability in patients with known CAD without angina 1

Etiology-Specific Workup (When Clinically Indicated)

Screen for Specific Cardiomyopathies When Suggested by Clinical Presentation:

• Cardiac amyloidosis: If increased LV wall thickness, neuropathy, or musculoskeletal issues—obtain monoclonal protein screen (serum/urine immunofixation, free light chains) and technetium pyrophosphate scan 1
• Hemochromatosis: If family history or frequent transfusions—check ferritin, transferrin saturation, and consider HFE genetic testing 1
• Cardiac sarcoidosis: If extracardiac disease or young patient with AV block—obtain cardiac MRI and FDG-PET scan 1
• Hypertrophic cardiomyopathy: If unexplained LV hypertrophy or family history—cardiac MRI if echocardiogram uncertain 1
• Viral myocarditis: If antecedent viral infection—cardiac MRI; consider endomyocardial biopsy in selected cases 1
• HIV, rheumatologic disorders: Screen based on risk factors and clinical presentation 2

Additional Testing in Selected Patients:

• Iron studies (ferritin, transferrin saturation, TIBC) to assess for iron deficiency 1
• Sleep study if clinical suspicion for obstructive sleep apnea 2
• Endomyocardial biopsy in cases of rapidly progressive HF, suspected infiltrative disease, or unclear etiology despite comprehensive workup 1

Immediate Therapeutic Considerations During Workup

Volume Management:

• Initiate loop diuretics (furosemide) for symptomatic relief of congestion and edema 2
• Monitor daily weights, strict intake/output, and clinical signs of decongestion 2
• Monitor renal function and electrolytes (especially potassium and magnesium) closely during diuresis 2

Troponin Assessment:

• Measure troponin I or T if any suspicion of acute coronary syndrome 2

Follow-Up Imaging Strategy

• Repeat echocardiography after 3-6 months of optimal guideline-directed medical therapy to reassess LVEF and guide decisions regarding device therapy (ICD, CRT) or advanced therapies 1
• In some patients, LV remodeling may continue to improve over 12 months, so longer observation may be reasonable before device decisions 1

Specialist Referral Triggers

Refer to heart failure specialist for: 1

• New-onset HF (regardless of EF) for evaluation of etiology and optimization of guideline-directed therapies
• Need for advanced imaging, endomyocardial biopsy, or genetic testing
• Persistently reduced LVEF ≤35% despite GDMT for ≥3 months (for device therapy consideration)
• High-risk features: persistent NYHA class III-IV symptoms, systolic BP <90 mmHg, creatinine ≥1.8 mg/dL, ≥2 hospitalizations in 12 months, or inability to tolerate GDMT

Critical Pitfalls to Avoid

• Do not assume the diagnosis without objective evidence of reduced LVEF on imaging 2
• Always consider reversible causes: peripartum cardiomyopathy, viral myocarditis, thyroid disease (hyper- or hypothyroidism), alcohol-induced cardiomyopathy, undiagnosed valvular disease, tachycardia-induced cardiomyopathy 2
• Do not miss infiltrative cardiomyopathies (amyloidosis, sarcoidosis, hemochromatosis) which require disease-specific therapies 1
• Recognize that heart failure should never be the final diagnosis—always identify the underlying etiology 1