B-type natriuretic peptide: a review of its diagnostic, prognostic, and therapeutic monitoring value in heart failure for primary care physicians.

BACKGROUND Congestive heart failure is misdiagnosed clinically 50% to 75% of the time. B-type natriuretic peptide (BNP) concentrations have shown to be useful in the diagnosis of heart failure in addition to having prognostic and therapeutic monitoring value. Studies were evaluated for validity and potential value of BNP measurements for managing patients with heart failure. METHODS A literature review using MEDLINE (1966 to present), CINAHL (1980 to present) and Evidence-Based Medicine Reviews was performed with the following key words: "cardiac neuro-hormone," "B-type natriuretic peptide," "congestive heart failure," and combination of the key terms. RESULTS AND CONCLUSIONS A BNP level of 80 pg/mL is useful in diagnosing heart failure in symptomatic patients without a history of heart failure. BNP is not specific for any disease state, however, especially in patients with a history of heart failure or left ventricular dysfunction. BNP levels are potentially more useful when a baseline concentration is known for a patient, because BNP levels are proportional to the severity of heart failure. The role of BNP as a prognostic marker and for therapeutic monitoring is closely related. Whereas larger studies are needed to support further recommendations, a goal to maintain a BNP concentration of less than 100 pg/mL has shown to correlate with functional improvement in patients with heart failure and has tended to decrease clinical endpoints, such as cardiovascular death. Consequently, using BNP concentrations to monitor patients with heart failure and manage their medical therapy accordingly might improve overall morbidity and mortality.