Specimen

Plasma

Collection Medium:

Minimum:

2 mL plasma separator tube top or 2 microtubes.

Rejection Criteria:

Red top tube is not acceptable.

Testing Schedule:

Random Access

Analytic Time:

1 hour (upon receipt in laboratory)

Reference Range:

The 95th percentiles for NT-proBNP levels in pg/mL

            < 45 yrs   45-54 yrs   55-64 yrs   65-74 yrs   75+ years
Males           93       138         177         229          852
Females        178       192         226         353          624


For Chronic Heart Failure patients according to NYHA Functional Class 
for NT-proBNP levels in pg/mL

                         NYHA I     NYHA II     NYHA III     NYHA IV
                Mean:     1015       1666         3029         3465
5th percentile              33        103          126          148
95th percentile           3410       6567        10449        12188


The Stages of Heart Failure - NYHA Classification

In order to determine the best course of therapy, physicians often 
assess the stage of heart failure according to the New York Heart 
Association (NYHA) functional classification system. This system 
relates symptoms to everyday activities and the patient's quality of 
life.

Class                 Patient Symptoms

Class I (Mild)        No limitation of physical activity. Ordinary
                      physical activity does not cause undue fatigue,
                      palpitation, or dyspnea (shortness of breath).

Class II (Mild)       Slight limitation of physical activity.
                      Comfortable at rest, but ordinary physical
                      activity results in fatigue, palpitation, or
                      dyspnea.

Class III (Moderate)  Marked limitation of physical activity.
                      Comfortable at rest, but less than ordinary
                      activity causes fatigue, palpitation, or dyspnea.

Class IV (Severe)     Unable to carry out any physical activity
                      without discomfort. Symptoms of cardiac
                      insufficiency at rest. If any physical activity
                      is undertaken, discomfort is increased.

Comments:

The N-terminal Pro-Brain Natriuretic Peptide (Pro-BNP) is an assay used 
as an aid in the diagnosis of individuals suspected of having 
congestive heart failure.  The test is further indicated for the risk 
stratification of patients with acute coronary syndrome and congestive 
heart failure.  The test may also be used as an aid in the assessment 
of increased risk of cardiovascular events and mortality in patients at 
risk for heart failure who have stable coronary artery disease.

NT-Pro-BNP is stable for 2 days at 2-8 degrees C, so this assay may be 
added to existing PST tubes during those two days.

Test
Limitations:

Hemolysis  H = 1400 mg/dL
Lipemia    L = 4000 mg/dL
Icterus    I = 35 mg/dL

Biotin <123 nmol/L or <30 ng/mL

In patients receiving therapy with high biotin >5mg/day, no sample 
should be taken until at least 8 hours after last biotin 
administration.

Methodology:

Electrochemiluminescence Imunoassay

CPT Code:

83880