Faculty Bibliography

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.

The incidence, as well as the morbidity and mortality associated with heart failure (HF) continue to rise despite advances in diagnostics and therapeutics. A recent advance in the diagnostic and therapeutic approach to HF is the use of natriuretic peptide (NP) testing, including both B-type natriuretic peptide (BNP) and its amino terminal cleavage equivalent (NT-proBNP). NPs may be elevated at an early stage among those with symptoms as well among those without. The optimal approach for applying NP testing in general populations is to select the target population and optimal cut off values carefully. Superior diagnostic performance is observed among those with higher baseline risk (such as hypertensives or diabetics). As well, unlike for acute HF, the cut off value for outpatient testing for BNP is 20-40 pg/mL and for NTproBNP it is 100-150 ng/L. In symptomatic primary care patients, both BNP and NT-proBNP serve as excellent tools for excluding HF based on their excellent negative predictive values and their use may be cost effective. Among those with established HF, it is logical to assume that titration of treatment to achieve lower NPs levels may be advantageous. There are several ongoing trials looking at that prospect.

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.