Heart Failure Diagnosis and Management

Diagnostic Thresholds

• BNP levels above 100 pg/mL or NT-proBNP levels above 300 pg/mL are indicative of heart failure, with higher values increasing the likelihood of diagnosis, as recommended by the American Heart Association and American College of Cardiology 1, 2, 3
• The established rule-out threshold is <100 pg/mL, which has a high negative predictive value of 90% sensitivity, and a rule-in threshold of >400 pg/mL is strongly suggestive of heart failure 1, 2, 4
• Age-adjusted rule-in thresholds are recommended: <50 years: >450 pg/mL, 50-75 years: >900 pg/mL, and >75 years: >1800 pg/mL, as suggested by the American College of Cardiology 1
• The following BNP classification can be used:

Treatment and Management

• Guideline-directed medical therapy for heart failure should include ACE inhibitor or ARB, beta-blocker, and mineralocorticoid receptor antagonist (e.g., spironolactone), as recommended by the American Heart Association, European Heart Journal, European Heart Society, and American College of Cardiology 7, 2, 8
• Angiotensin receptor-neprilysin inhibitor (ARNI) such as sacubitril/valsartan is recommended as the preferred first-line therapy for patients with HFrEF NYHA class II or III, according to the American College of Cardiology 9
• SGLT2 inhibitors should be used for patients with diabetes and heart failure, as recommended by the American Diabetes Association 10
• Mineralocorticoid receptor antagonists, such as spironolactone, should be started at a dose of 12.5-25 mg daily, with monitoring of potassium and renal function after 4-6 days, as suggested by the European Society of Cardiology 11
• Intravenous inotropes may be considered for patients with severe heart failure with pulmonary congestion and peripheral hypoperfusion, according to the European Society of Cardiology 11
• Nesiritide, a recombinant BNP, may be considered for acute heart failure to improve dyspnea and induce vasodilation, as recommended by the European Society of Cardiology 11

Patient Evaluation and Monitoring

• BNP testing improves evaluation and treatment of patients with acute dyspnea in emergency departments, reducing time to discharge and total cost of treatment, as recommended by relevant medical guidelines 2
• Echocardiography should be used to assess left ventricular ejection fraction, chamber sizes, valvular function, diastolic function, and estimated filling pressures, and cardiac MRI if structural abnormalities need further evaluation, as recommended by the American College of Cardiology 12
• Coronary angiography should be considered if ischemia is suspected, as part of the diagnostic evaluation, according to the American College of Cardiology 12
• Daily weights, blood pressure, and heart rate should be monitored, as well as symptoms of heart failure, such as dyspnea, edema, and fatigue, in the short-term (1-2 weeks), according to relevant medical guidelines 13
• Electrolytes and renal function should be monitored within 1-2 weeks of starting therapy, and follow-up BNP measurement should be done in 1-2 months, with a reduction >30% indicating a good response, as recommended by the American Heart Association and European Society of Cardiology 6, 14, 1, 15, 16, 17, 18, 19

Special Considerations

• Advanced age, renal dysfunction, atrial fibrillation, pulmonary hypertension, pulmonary embolism, right ventricular dysfunction, mitral regurgitation, and sepsis may affect BNP levels, as noted by relevant medical guidelines 1
• Obesity (BMI >30 kg/m²) may require adjusted thresholds, as suggested by the American College of Cardiology and European Society of Cardiology 1, 4
• Patients should be educated on daily weight monitoring, sodium restriction (<2g/day), fluid restriction if indicated, recognition of worsening heart failure symptoms, medication adherence, and when to seek immediate medical attention, with consideration of factors such as age, sex, weight, and renal function when interpreting BNP levels, as recommended by relevant medical guidelines 4, 16, 15
• Referral to a heart failure specialist should be considered based on the "I-NEED-HELP" criteria, which include IV inotropes needed, NYHA IIIB/IV or persistently elevated natriuretic peptides, ejection fraction ≤35%, defibrillator shocks, hospitalizations >1, edema despite escalating diuretics, low blood pressure, high heart rate, and progressive intolerance or down-titration of GDMT, as recommended by the American College of Cardiology 12