ORIGINAL ARTICLE Nt-proBNP in haemodialysis patients: A preliminary study

Objective. N-terminal pro-brain natriuretic peptide (Nt-proBNP) is a marker of left ventricular function. Although many factors can increase left ventricular dysfunction in haemodialysis patients, the role of Nt-proBNP is uncertain. Material and methods. Serum concentrations of Nt-proBNP and troponin T were measured by electrochemiluminescence and C-reactive protein by immunoturbidimetry in 52 dialysis patients followed-up for 36 months. Results. Nt-proBNP correlated (pv0.05) with time on haemodialysis (rho50.345), left ventricular mass index (r50.596), troponin T level (r50.605) and age (r50.296). Patients with a history of heart disease showed higher levels of Nt-proBNP (median; minimum-maximum ngl/L) (15,571; 1,553–209,451) than those without (4,535; 751–115,078) (pv0.01). Sensitivity and specificity of Nt-proBNP in the detection of left ventricular dysfunction (ventricular ejection fraction v45 %) were 1.0 and 0.782, respectively. In the univariate analysis, patients with Nt-proBNP levels >33,314 ng/L, CRP >5 mg/L or troponin T >0.1 mg/L had poorer probabilities of 1-year, 2-year and 3-year survival than patients with lower levels. Unfavourable prognostic factors in the multivariate analysis were CRP w5 mg/L and Tn T w0.1 mg/L. Conclusions. Nt-proBNP showed good diagnostic performance for detecting left ventricular dysfunction and was an important predictor of mortality in haemodialysis patients in the univariate analysis. In the multivariate analysis, Nt-proBNP lost its prognostic value, whereas for CRP and Tn T it was maintained.