Amino-terminal pro-B-type natriuretic peptide and B-type natriuretic peptide in the general community: determinants and detection of left ventricular dysfunction.

OBJECTIVES: This study sought to characterize factors influencing amino-terminal pro-B-type natriuretic peptide (NT-proBNP) and to evaluate the ability of NT-proBNP to detect left ventricular (LV) dysfunction in a large community sample.

BACKGROUND: Secretion of BNP increases in cardiac disease, making BNP an attractive biomarker. Amino-terminal proBNP, a fragment of the BNP prohormone, is a new biomarker. We evaluated factors influencing NT-proBNP in normal patients and compared the ability of NT-proBNP and BNP to detect LV dysfunction in a large community sample.

METHODS: Amino-terminal pro-BNP was determined in plasma samples of a previously reported and clinically and echocardiographically characterized random sample (n = 1,869, age > or =45 years) of Olmsted County, Minnesota.

RESULTS: In normal patients (n = 746), female gender and older age were the strongest independent predictors of higher NT-proBNP. Test characteristics for detecting an LV ejection fraction < or =40% or < or =50% were determined in the total sample with receiver operating characteristic curves. Amino-terminal pro-BNP had significantly higher areas under the curve for detecting an LV ejection fraction < or =40% or < or =50% than BNP in the total population and in several male and age subgroups, whereas areas were equivalent in female subgroups. Age- and gender-adjusted cutpoints improved test characteristics of NT-proBNP. Both assays detected patients with systolic and/or moderate to severe diastolic dysfunction to a similar degree, which was less robust than the detection of LV systolic dysfunction alone.

CONCLUSIONS: Amino-terminal pro-BNP in normal patients is affected primarily by gender and age, which should be considered when interpreting values. Importantly, in the entire population sample NT-proBNP performed at least equivalently to BNP in detecting LV dysfunction and was superior in some subgroups in detecting LV systolic dysfunction.