Anticipating the time to renal replacement therapy (RRT) in chronic kidney disease (CKD) patients is an important but challenging issue. Natriuretic peptides are biomarkers of ventricular dysfunction related to poor outcome in CKD. We comparatively investigated the value of B-type natriuretic peptide (BNP) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) as prognostic markers for the risk of RRT in stages 4 and 5 CKD patients, and in foretelling all-cause mortality and major cardiovascular events within a 5-year follow-up period.

Baseline plasma BNP (Triage, Biosite) and NT-proBNP (Elecsys, Roche) were measured at inclusion. Forthy-three patients were followed-up during 5 years. Kaplan-Meier analysis, with log rank testing and hazard ratios (HR), were calculated to evaluate survival without RRT, cardiovascular events or mortality. The independent prognostic value of the biomarkers was estimated in separate Cox multivariate analysis, including estimated glomerular filtration rate (eGFR), creatininemia and comorbidities.

During the first 12-month follow-up period, 16 patients started RRT. NT-proBNP concentration was higher in patients who reached endpoint (3221ng/L vs. 777ng/L, P=0.02). NT-proBNP concentration>1345ng/L proved significant predictive value on survival analysis for cardiovascular events (P=0.04) and dialysis within 60 months follow-up (P=0.008). BNP concentration>140ng/L was an independent predictor of RRT after 12 months follow-up (P<0.005), and of significant predictive value for initiation of dialysis within 60 months follow-up.

Our results indicate a prognostic value for BNP and NT-proBNP in predicting RRT in stages 4 and 5 CKD patients, regarding both short- and long-term periods. NT-proBNP also proved a value in predicting cardiovascular events.

Natriuretic peptides could be useful predictive biomarkers for therapeutic guidance in CKD.