With nearly 500,000 new cases per year and direct costs estimated as high as US$38 billion annually, congestive heart failure (CHF) has become a major priority in modern medicine. This crisis will continue to grow as the population ages, thus the discernment of new diagnostic and therapeutic strategies to improve prognosis and reduce costs is critical.1
The irony is that therapies with great benefit for patients with CHF exist, such as angiotensin converting enzyme (ACE) inhibitors and beta-blockers. However, these agents are under-utilized, and when employed may be dosed inadequately.2,3 Accordingly, a widely available and accurate diagnostic tool to identify those with CHF would be essential in order to identify those patients eligible for proven therapies in CHF. Such a diagnostic tool for early diagnosis would theoretically lead to earlier initiation of these beneficial medicines while potentially assisting in chronic out-patient management of such patients. As CHF is the leading cause of hospitalization in adults over 65, achieving such early diagnosis and initiation of therapy would thus prevent hospitalizations and reduce the considerable costs of CHF.4
Markers of cardiac neurohormonal activation, particularly B-type natriuretic peptides, have been identified as possible tools to identify and treat patients with CHF.While most studies to date have focused on the diagnostic utility of B-type natriuretic peptide (BNP), more recent research has revealed that the amino-terminal fragment of the BNP molecule (NT-proBNP), a marker with great diagnostic and prognostic power, is a marker for CHF. Recently, a new automated immunoassay has made NT-proBNP testing a reality for diagnostic, prognostic, and possibly therapeutic, purposes in CHF.5 This paper reviews some of the growing evidence behind the use of NT-proBNP in patients with CHF.
Biology of Natriuretic Peptides
The natriuretic peptides are a family of molecules consisting of several structurally-related hormones. At present, the natriuretic peptide family includes atrial natriuretic peptide (ANP), B-type (or brain) natriuretic peptide (BNP), C-type natriuretic peptide (CNP), and dendroaspis natriuretic peptide (DNP).