**Abstract:**  
  
B-type natriuretic peptide (BNP) is a cardiac neurohormone produced mainly in
the left ventricle. It is secreted in response to ventricular volume expansion
and pressure overload, factors often found in congestive heart failure (CHF).
Used in conjunction with other clinical information, rapid measurement of BNP
is useful in establishing or excluding the diagnosis and assessing the
severity of CHF in patients with acute dyspnea so that appropriate and timely
treatment can be initiated. This test is also used to predict the long-term
risk of cardiac events or death across the spectrum of acute coronary
syndromes when measured in the first few days after an acute coronary event.
For the purposes of this policy, either total or N-terminal assays are
acceptable. This policy documents CGS indications and limitations of coverage
for BNP testing.  
  
 **Indications:**  
  
BNP measurements may be considered reasonable and necessary when used in
combination with other medical data such as medical history, physical
examination, laboratory studies, chest x-ray, and electrocardiography:  
  

  * To distinguish cardiac cause of acute dyspnea from pulmonary or other non-cardiac causes. Plasma BNP levels are significantly increased in patients with CHF presenting with acute dyspnea compared with patients presenting with acute dyspnea due to other causes.
  * To distinguish decompensated CHF from exacerbated chronic obstructive pulmonary disease (COPD) in a symptomatic patient with combined chronic CHF and COPD. Plasma BNP levels are significantly increased in patients with CHF with or without concurrent lung disease compared with patients who have primary lung disease. 
  * As a risk stratification tool (to assess risk of death, myocardial infarction or congestive heart failure) among patients with acute coronary syndrome (myocardial infarction with or without T-wave elevation and unstable angina). Obtained in the first few days after the onset of ischemic symptoms, results of BNP measurement can provide useful information.

  
**Limitations:**  
  
BNP measurements must be analyzed in conjunction with standard diagnostic
tests, medical history and clinical findings. The efficacy of BNP measurement
as a stand-alone test has not yet been established. Clinicians should be aware
that certain conditions such as ischemia, infarction and renal insufficiency,
may cause elevation of circulating BNP concentration and require alterations
of the interpretation of BNP results.  
  
Additional investigation is required to further define the diagnostic value of
plasma BNP in monitoring the efficiency of treatment for CHF and in tailoring
the therapy for heart failure. Therefore, BNP measurements for monitoring and
management of CHF are not a covered service.  
  
Although a correlation between serum BNP levels and the clinical severity of
HF has been shown in broad populations, "it cannot be assumed that BNP levels
can be used effectively as targets for adjustment of therapy in individual
patients. [T]he BNP measurement has not been clearly shown to supplement
careful clinical assessment." (Hunt SA, Abraham WT, Chin MH, et al. ACC/AHA
2005 Guideline Update for the Diagnosis and Management of Chronic Heart
Failure in the Adult: A Report of the American College of Cardiology/American
Heart Association Task Force on Practice Guidelines, pgs. 14-15)