Abstract
Comparison of B-Type Natriuretic Peptides for Assessment of Cardiac Function and Prognosis in Stable Ischemic Heart Disease
Mark Richards, M. Gary Nicholls, Eric A. Espiner, John G. Lainchbury, Richard W. Troughton, John Elliott, Christopher M. Frampton, Ian G. Crozier, Timothy G. Yandle, Robert Doughty, Stephen MacMahon, Norman Sharpe, for the Christchurch Cardioendocrine Research Group and the Australia-New Zealand Heart Failure Group
In 1,049 patients with stable ischemic heart disease (IHD), brain natriuretic peptide (BNP) and amino terminal pro-brain natriuretic peptide (NTproBNP) correlated closely (r = 0.09, p < 0.001) and were similarly related to left ventricular ejection fraction (LVEF) (r = −0.50 and −0.46, respectively), age (0.44 and 0.47), and creatinine clearance (−0.51 and −0.51). Receiver-operating characteristic curves for detection of LVEF <30% were similar (area under the curves = 0.83 and 0.80, both p < 0.001), and both peptides had strong negative predictive value (95% and 94%). Both independently predicted all-cause mortality and/or heart failure with closely overlapping event-free survival curves; BNP and NTproBNP display strong, near-identical test performance in ruling about severely reduced LVEF and in prediction of all-cause mortality or heart failure in stable IHD.
The aim of this work was to test B-type natriuretic peptides for assessment of function and prognosis in stable ischemic heart disease (IHD) and to compare brain natriuretic peptide (BNP) with amino terminal pro-brain natriuretic peptide (NTproBNP), including the relative effects of age and renal function on test performance.
Brain natriuretic peptide and NTproBNP are emerging diagnostic and prognostic markers in heart failure and acute coronary syndromes. Their performance in assessing function and prognosis in stable IHD is unknown. Whether one marker is superior and the relative effects of age and renal function on test performance are uncertain.
In 1,049 patients with stable IHD, left ventricular ejection fraction (LVEF) was measured by radionuclide scanning and creatinine clearance estimated by the Cockroft-Gault equation. Age, gender, and body mass index were recorded. Twelve-month all-cause mortality or admission with heart failure was prospectively recorded; BNP and NTproBNP were measured by radioimmunoassay.
Brain natriuretic peptide and NTproBNP correlated closely (r = 0.90, p < 0.001) and had similar relationships to LVEF (r = −0.50 and −0.46, respectively, both p < 0.001), age (0.44 and 0.47, both p < 0.001), and creatinine clearance (−0.51 and −0.51, both p < 0.001). Areas under receiver-operating characteristic curves for detection of LVEF <30% were similar (0.83 and 0.80, both p < 0.001) with strong negative predictive values for both (95% and 94%). Both markers independently predicted the clinical end point with closely overlapping event-free survival curves.
In stable IHD, BNP and NTproBNP display strong and near-identical test performance in ruling out severely reduced LVEF and in prediction of all-cause mortality or heart failure despite significant effects of age, gender, and renal function on levels of both markers.