BACKGROUND
In hemodialysis, the relationship between the increased concentration of natriuretic peptides and volume overload, inflammatory activity, endothelial dysfunction, left ventricular function and mass, and silent ischemic events is not clear. To investigate the relationship, a 3-year prospective cohort study was conducted in 50 adult hemodialysis patients in NYHA class I-II who were free from diabetes and ischemic heart events.
METHODS
Doppler echocardiogram, plasma NT-proBNP, troponin T and I, CRP, TNF alpha, big-endothelin 1, and cystatin-C, were determined both before and after a dialysis session. The outcome was all-cause death.
RESULTS
13 out of 50 patients died. Survival curves significantly differed by age (above vs. below the median 68 yrs), NT-proBNP (9719 pg/mL), troponin T (0.03 ng/mL), C-reactive protein (4.8 mg/L), left atrial volume index (51 mL/sqm), ejection fraction (61%), and diastolic pattern. In the Cox model only NT-proBNP (cutoff 10000 pg/mL) had a significant hazard ratio (4.1). Post-HD measurements of NT-proBNP, troponin T, and CRP maintained their prognostic value. The high correlation between pre and post values of NT-proBNP, and the lack of correlation with ultrafiltration volume excluded a role for acute fluid removal on its regulation.
CONCLUSIONS
The increased level of NT-proBNP is the most important prognostic factor even in the absence of severe heart dysfunction and myocardial ischemic events, without any relationship with endothelial dysfunction, inflammatory biomarkers, or with acute fluid removal. A cutoff value of NT-proBNP of 10000 pg/mL could be used to identify hemodialysis patients with a higher risk of death.