Diagnosing Heart Failure with Reduced Ejection Fraction (HFrEF)

Essential Elements for Diagnosis

• The American College of Cardiology and European Heart Society recommend confirming three essential elements for the diagnosis of HFrEF in a patient with NYHA Class III symptoms: clinical syndrome of heart failure, left ventricular ejection fraction ≤40% documented by echocardiography, and elevated natriuretic peptides above age-specific thresholds 1, 2
• The diagnosis is fundamentally clinical, based on specific symptoms and signs rather than any single test, with the American College of Cardiology emphasizing the importance of documenting characteristic symptoms such as dyspnea on exertion, fatigue, and exercise intolerance 3
• Verification of NYHA Class III status is crucial, with the patient being comfortable at rest but experiencing marked limitation with less than ordinary physical activity, as recommended by the American Heart Association 1, 3

Documenting Left Ventricular Systolic Dysfunction

• Echocardiography is the primary modality to confirm HFrEF, with the American College of Cardiology recommending quantitative LVEF measurement, and a threshold of ≤40% confirming HFrEF, although some guidelines use ≤35% for device therapy eligibility 1, 2, 4
• The European Heart Society suggests documenting left ventricular dilatation, with increased LV end-diastolic diameter (>55 mm or >30 mm/m²) supporting the diagnosis 5

Measuring Natriuretic Peptides

• Elevated BNP or NT-proBNP above age- and context-specific thresholds is central to diagnosis, helping differentiate cardiac from non-cardiac causes of dyspnea, with the European Heart Society recommending measurement in all patients with suspected heart failure 2

Determining Heart Failure Etiology

• Identifying the underlying cause is essential, as it influences prognosis and treatment, with the American College of Cardiology highlighting ischemic heart disease as the most common cause in Western populations, and recommending documentation of history of MI, coronary revascularization, or angina 1, 3, 4

Assigning ACC/AHA Heart Failure Stage

• Stage C is appropriate for patients with current or past symptoms of heart failure associated with structural heart disease, with the American College of Cardiology recommending assignment of this stage for patients with symptomatic heart failure (NYHA Class III) and documented structural abnormality 1