NEWS & EVENTS

NEWS ARCHIVE | EDUCATIONAL RESOURCES

CARDIOVASCULAR NATRIURETIC PEPTIDES
Abstract

Atrial natriuretic peptide (ANP), "B-type" (first discovered in brain tissue) natriuretic peptide (BNP), and "C-type" natriuretic peptide (CNP) are newly identified peptide hormones which, along with vasopressin, renin-angiotensin, and aldosterone, comprise the fundamental physiologic hormonal mechanisms through which the human cardiovascular/renal salt/water/volume relationships are controlled.

Clinically, blood levels of these hormones and their precursors are elevated under the following conditions:

• congestive heart failure
• myocardial infarction
• volume and salt overload
• cardiomyopathy
• mitral/aortic stenosis

Test specificity is greater than 98%, meaning that 2% or less of patients without CHF would test as (false) positive (high negative predictive value).

BNP levels have been shown to be strongly predictive of survival in the clinical circumstance of heart failure after myocardial infarction. In patients with an acute coronary syndrome, a single early elevated blood level of BNP is associated with a higher risk of death, recurrent heart attack, development of heart failure or progression of heart failure. Further, BNP blood levels change very early in congestive heart failure and ventricular dysfunction, providing an inexpensive, non-invasive screen to determine if more invasive, expensive modalities are needed. BNP has also been shown to have utility in distinguishing between the dyspnea of congestive heart failure and chronic obstructive pulmonary disease (COPD).

This new rapidly expanding area of clinical laboratory testing, pharmaceutical and clinical research holds great promise to enable clinicians to more quickly and accurately identify and predict treatable cardiovascular abnormalities, attenuate their courses, preserve myocardium and cardiac functional capabilities, and use resources more effectively.

Physicians Reference Laboratory is pleased to announce the current availability of testing for brain-type natriuretic peptide (BNP). The specimen for testing is whole blood or plasma using EDTA as the anticoagulant. If testing cannot be accomplished within 4 hours, the separated plasma should be stored at -20 degrees C until tested.

To read a more in-depth discussion of Cardiovascular Natriuretic Peptides, click here.

Kenneth C. Cummings, MD
Chief, Clinical Pathology
May, 2002