[Is the N-terminal pro-B-type natriuretic peptide a predictor of cardiovascular events in hemodialysis patients?].

Aim To evaluate the role of N-terminal pro-hormone brain natriuretic peptide (NT-proBNP) as a predictor of cardiovascular events (CVE) in patients receiving programmed hemodialysis (PHD).Material and methods This study included 74 patients (men, 64.8 %) older than 18 years receiving PHD. Data were processed using mean values of standard biochemical indexes for 16 months. NT-proBNP level was measured and transthoracic echocardiography (EchoCG) and bioimpedancemetry were performed at the time of inclusion into the study. Cumulative incidence of CVE for 16 months was evaluated in patients with different levels of NT-proBNP (quartile 1: <1127 pg/ml; quartile 1-4: 1127-3210 pg/ml; quartile 4: >3210 pg/ml) using the Kaplan-Meier method. For assessment of NT-proBNP as a CVE predictor, receiver operational characteristic curves (ROC curves) were constructed.Results The serum concentration of NT-proBNP was 2114.5 [1127; 3210.4] pg/ml. During 16 months, CVE were observed in 25.6 % of patients. The risk of CVE increased with increasing NT-proBNP quartile in the analysis of Kaplan-Meier curves (Log-Rank test, p=0.032). In this process, CVE did not develop in patients with NT-proBNP concentrations lower than 1127 pg/ml. The ROC analysis demonstrated a good predictive value of NT-proBNP (p=0.006, AUC 0.71, 95 % CI: 0.59-0.83). The optimum cut-off threshold of the NT-proBNP level predictive of CVE was 2093 pg/ml (sensitivity, 84.2 %, specificity, 58.2 %). CVE developed in patients with greater values of volumetric myocardial parameters, indirect signs of hyperhydration (higher predialysis sodium level and pulmonary artery systolic pressure), smaller volumes of substituate per dialysis procedure, and left ventricular systolic dysfunction (p<0.05).Conclusion In patients receiving programmed extracorporeal therapy, the serum concentration of NT-proBNP was considerably higher than mean values in the general population. Apparently, serum NT-proBNP concentrations in the range of 1127-2093 pg/ml can be used as a predictor for a high risk of CVE in the dialysis population. Pronounced structural alterations of the myocardium, left ventricular systolic dysfunction, and hyperhydration are the factors that provide development of CVE on PHD. Large volumes of the PHD substitution solution are associated with a lower incidence of CVE in the dialysis population.