Although the cardiac biomarker troponin T (cTnT) is strongly related to mortality in end-stage renal disease, the independent association of N-terminal pro-B-type natriuretic peptide (NT-proBNP) and cTnT in predicting outcomes is unknown.
To determine factors associated with NT-proBNP and cTnT, and to determine whether these levels are associated with mortality.
Settings and Participants:
Asymptomatic hemodialysis patients (n=150) in 4 university-affiliated hemodialysis units.
Exposure and Outcomes:
For cross-sectional analysis, echocardiographic variables as exposures and N-terminal proBNP and cardiac troponin T as outcomes; for longitudinal analysis, association of N-terminal proBNP and cardiac troponin T as exposures to all-cause and cardiovascular disease mortality as outcomes.
In a multivariate regression analysis, low midwall fractional shortening a measure of poor systolic function was an independent correlate of log NT-proBNP (p<0.01), while left ventricular mass index was an independent correlate of cTnT (p<0.01). Over a median follow-up of 24 months, 46 patients died of which, 26 died due to cardiovascular causes. NT-ProBNP had a strong graded relationship with all-cause (Hazard Ratio (HR) 1.54, 4.78 and 4.03 for increasing quartiles, Chi2 32.2, p<0.001) and cardiovascular mortality (HR 2.99, 10.95, 8.54 Chi2 23.66, p<0.01), while cTnT had a weaker relationship with all-cause (HR 1.57, 2.32, 3.39, Chi2 23.09, p<0.01) and cardiovascular mortality (HR 1, 0.81, 2.12, 2.14, Chi2 15.05, p=0.1). The combination of the two biomarkers did not improve the association with all-cause or cardiovascular mortality compared to NT-proBNP alone. NT-proBNP was a marker of mortality even after adjusting for left ventricular mass index and midwall fractional shortening.
Our cohort was predominantly black and of limited sample size.
NT-proBNP strongly correlates with left ventricular systolic dysfunction and is more strongly associated with mortality than cTnT in asymptomatic hemodialysis patients.