Prognostic value of cardiac biomarkers for death in a non-dialysis chronic kidney disease population.

Background: Excess mortality in patients with chronic kidney disease (CKD) is predominantly due to cardiovascular disease. We explored the prognostic value of biomarkers of cardiac overload [B-type natriuretic peptide (BNP) and N-terminal pro-B-type natriuretic peptide (NT-proBNP)] and inflammation [high-sensitivity C-reactive protein (hsCRP)] for all-cause mortality in patients with CKD.

Methods: Plasma BNP (Siemens Medical Solutions Diagnostics, Frimley, Surrey, UK) and NT-proBNP (Roche Diagnostics PLC, East Sussex, UK), and hsCRP (Siemens Medical Solutions Diagnostics) were measured at study entry. Echocardiograms were undertaken, and left ventricular mass index (LVMI) was calculated. CKD patients (n = 213) were followed for up to 53 months. Kaplan-Meier survival analysis with log-rank testing and hazards ratios (HRs) were calculated for each cardiac biomarker, stratified by respective median values, as a predictor of death to assess outcome.

Results: Fifty-four deaths occurred. NT-proBNP concentration >or=89 pmol/L (HR 5.6, P < 0.0001), BNP concentration >or=14 pmol/L (HR 3.5, P < 0.001), NT-proBNP/BNP ratio >or=6 pmol/pmol (HR 2.6, P < 0.01) and hsCRP concentration >or=4.7 mg/L (HR 2.4, P < 0.01) were unadjusted predictors of death. Only NT-proBNP >or=89 pmol/L (HR 2.5, P < 0.05) and hsCRP >or=4.7 mg/L (HR 1.9, P < 0.05) were independent predictors of death when the HRs were adjusted for significant clinical variables (age, estimated glomerular filtration rate, LVMI and vascular disease).

Conclusion: NT-proBNP and hsCRP can independently predict all-cause mortality in a non-dialysis CKD population and may have a useful role in risk stratification.