What is the significance of Brain Natriuretic Peptide (BNP)?

From the Guidelines

BNP levels are a crucial diagnostic and prognostic marker for heart failure, and their measurement can significantly support clinical decision-making in both outpatient and inpatient settings. When a patient presents with symptoms like shortness of breath, fatigue, or swelling, a BNP blood test can help determine if heart failure is the cause, with levels above 400 pg/mL strongly suggesting heart failure 1. The related NT-proBNP test works similarly but has different reference ranges. BNP levels increase with age and in women, and can be elevated in other conditions like kidney disease, pulmonary embolism, or severe infections, and may be falsely low in obese patients 1.

Key Points to Consider

• BNP testing is valuable for both diagnosis and monitoring treatment effectiveness in heart failure patients, as decreasing levels often indicate improving cardiac function in response to therapy 1.
• Initial BNP level on presentation with dyspnea to an acute care setting is a powerful predictor of short- and long-term outcomes, with higher levels associated with increased morbidity and mortality 1.
• Predischarge BNP levels are a stronger marker of postdischarge outcomes than either baseline or percent change in BNP during hospitalization, with a predischarge BNP ≤430 pg/mL having strong negative predictive value for 30-day readmission 1.
• NT-proBNP levels also provide valuable prognostic information, with baseline NT-proBNP concentration >986 pg/mL being the strongest predictor of 1-year mortality in some studies 1.

Clinical Application

• Measurement of BNP or NT-proBNP is recommended to support clinical decision-making in the diagnosis of heart failure, especially when there is clinical uncertainty 1.
• BNP- or NT-proBNP–guided therapy can be useful to achieve optimal dosing of medical therapy in select clinically euvolemic outpatients in structured management programs 1.
• In hospitalized patients, measurement of BNP or NT-proBNP may be useful to support clinical judgment for the diagnosis of acutely decompensated heart failure, especially when the diagnosis is uncertain 1.

From the Research

B-Type Natriuretic Peptide (BNP)

• BNP is a hormone produced by the heart and is used as a marker for heart failure diagnosis and prognosis 2, 3, 4.
• Elevated BNP levels are associated with increased risk of death and cardiovascular events in patients with heart failure 3, 5.
• BNP testing is useful in ruling out heart failure, particularly in patients presenting with acute dyspnea 2, 4.

Clinical Applications of BNP

• BNP testing can be used to diagnose heart failure, including diastolic dysfunction 3.
• Serial BNP measurements can be used to monitor patients with heart failure and predict short-term prognosis 5.
• BNP levels can be affected by various factors, including age, gender, comorbidity, and drug therapy 2, 3.

Diagnostic and Prognostic Value of BNP

• Low BNP levels can rule out heart failure, while elevated levels indicate increased risk of cardiovascular events and mortality 3, 4.
• BNP testing has a high negative predictive value, making it useful for ruling out heart failure in patients with suspected heart failure 2, 4.
• The optimal use of BNP determination requires consideration of patient history, physical examination, and other diagnostic tools 4.

Limitations and Future Directions

• BNP measurements should not be used in isolation from clinical context, as various factors can affect BNP levels 2, 3.
• Further research is needed to establish the optimal use of BNP testing in clinical practice, including the frequency of measurements and the role of serial measurements in monitoring patients with heart failure 5, 6.