Clinical utility of NTproBNP as a fluid assessment and prognostic tool in PD patients

The N-terminal pro-brain natriuretic peptide (NTproBNP) is a proven biomarker of myocardial structure/function and fluid volume status in the general population and prognostic marker of survival in cardiac failure patients. However, its utility for ESRD patients on peritoneal dialysis (PD) is under-studied. Our study aimed to evaluate the correlation of NTproBNP level with various biochemical parameters, fluid status and heart function in PD patients. Also, to determine the cutoff of NTproBNP level in predicting hypervolemic state. This is a cross-sectional study of stable peritoneal dialysis patients in the University of Malaya. Consented patients will be subjected to biochemical, echocardiogram, and bio-impedance analysis. Hypervolemic state is defined by an extracellular water/total body water (ECW/TBW) ratio of ≥ 0.40. NTproBNP level was taken at the same setting. 77 patients were recruited with male to female of 61% (n = 47) and 39% (n = 30). 33 patients (42.9%) were found to have over-hydration. There was a positive correlation between logNTproBNP with logECW/TBW ratio (r = 0.60, p = < 0.01). The performance of NTproBNP as a screening tool for over-hydration yielded an area under the ROC curve (AUC) of 0.80 (CI 95%; 0.701-0.898; P = < 0.001), and a threshold value of 2305 pg/ml has a sensitivity of 90%, specificity of 62%. The mortality rate at short-term follow-up was statistically higher in the high NTproBNP cohort (0% vs 17.9%; p = 0.027). Our study confirmed that NTproBNP correlates with hydration status in the PD cohort. It's useful in predicting clinical phenotypes and potentially a prognostic marker for patient survival.