Faculty Bibliography

Since the discovery of atrial natriuretic factor in 1981 by de Bold et al, there has been tremendous progress in our understanding of natriuretic peptides (NPs). Recently, testing for brain-type NP (BNP) and its amino terminal cleavage equivalent (NT-proBNP) has been rapidly adopted in clinical medicine for numerous indications, including the diagnosis and exclusion of heart failure (HF). In this regard, logical application of BNP or NT-proBNP testing may not only reduce healthcare costs but also potentially reduce adverse clinical outcomes. With respect to this fact, the potential importance of the concentration of the NPs for prognosis and the response of BNP or NT-proBNP to therapeutic intervention in terms of clinical events has been demonstrated. On the basis of these observations it is reasonable to expect that concentrations of these peptides might be useful for the management of patients with HF, acting as a gauge of therapeutic accuracy and/or stability of disease. Besides HF, the prognostic utility of NPs has been explored in other settings, particularly in ischemic heart disease and those conditions that lead to right ventricular dysfunction.

BACKGROUND:Acute dyspnea is common in the emergency department (ED) and is associated with mortality. Biomarkers may help stratify risk in this setting. METHODS:Among 577 dyspneic subjects we identified 5 candidate biomarkers with prognostic value: amino terminal B-type natriuretic peptide (NT-proBNP), C-reactive protein (CRP), the interleukin family member ST2, hemoglobin and blood urea nitrogen (BUN); these were assessed using both receiver operating characteristic curve and Cox proportional hazards analyses. Results were validated in a population of dyspneic patients from a distinct cohort. RESULTS:At 1 y follow up, 93 (16.1%) patients had died. Independent predictive ability was established in an age-adjusted Cox model containing all markers: NT-proBNP (HR=1.89); CRP (HR=1.95); ST2 (HR=7.17); hemoglobin (HR=1.68); BUN (HR=2.06) (all P<.05). Following categorical assessment based on number of abnormal markers, the 1-y risk of death increased in a monotonic fashion with mortality rates of 0%, 2.0%, 7.8%, 22.3%, 29.3%, and 57.6% respectively; similar results were seen in the validation set. CONCLUSION/CONCLUSIONS:Simultaneous assessment of pathophysiologically diverse markers in acute dyspnea provides powerful, independent and incremental prognostic information.

Use of natriuretic peptide to guide heart failure therapy represents a promising option. Although natriuretic peptides provide accurate diagnostic and independent incremental prognostic information, their use to gauge and titrate therapy is not yet fully realized.