Prognostic potential of brain natriuretic peptide (BNP) in predialysis chronic kidney disease patients

Abstract

In the present study, we investigated the potential of N-BNP (N-terminal B-type natriuretic peptide) as a prognostic marker for risk of CV (cardiovascular) events, overall mortality and progression to ESRD (end-stage renal disease) in a cohort of 83 pre-dialysis CKD (chronic kidney disease) patients without clinical evidence of heart failure. During the study, ten patients reached the combined end point of overall mortality and/or CV event. Univariate factors associated with the combined end point were plasma N-BNP (P < 0.0005), creatinine (P < 0.002), systolic blood pressure (P < 0.009) and age (P < 0.015). N-BNP levels were higher in patients with CV events (P < 0.0005). Cox model regression analysis yielded log10 N-BNP (hazard ratio, 9.608; P < 0.007) and pre-existing CV disease (hazard ratio, 4.571; P < 0.029) as independent predictors of overall mortality or CV events. Kaplan-Meier analysis curves for the subgroup with supramedian creatinine levels (225 micromol/l) showed significant separation of the curves stratified for plasma N-BNP levels above and below the group median (291 pmol/l) for all end points. Receiver-operator-characteristic curves for N-BNP (355 pmol/l cut-off) demonstrated a specificity of 65.8% at a sensitivity of 100% for predicting CV events/overall mortality. The measurement of plasma N-BNP may aid in the risk stratification of pre-dialysis CKD patients. The high sensitivity and negative predictive value (100%) may enable the selection of patients who could safely be excluded from further investigations, resulting in better focusing of resources.