Diagnostic potential of serum biomarkers for left ventricular abnormalities in chronic peritoneal dialysis patients

Background. N-terminal-pro-brain natriuretic peptide, cardiac troponin T (cTnT) and high sensitivity C-reactive protein (hs-CRP) have been shown to predict mortality and cardiovascular outcomes in end-stage renal disease patients. However, it is not known which biomarkers have the strongest diagnostic potential for left ventricular (LV) abnormalities in chronic peritoneal dialysis (PD) patients, nor whether residual renal function may confound the diagnostic potential of these biomarkers. Methods. Two hundred and thirty chronic PD patients underwent two-dimensional echocardiography to determine LV hypertrophy and ejection fraction and had simultaneous measurement of serum NT-pro-BNP, cTnT and hs-CRP. Results. A significant gain in predictive power was observed when NT-pro-BNP or cTnT but not hs-CRP was included in the multivariable logistic regression models for severe LV hypertrophy (defined as LV mass index >= upper tertile, 247.8 g/m(2)) and systolic dysfunction (defined as ejection fraction <= 45%). Using ROC curve analysis, NT-pro-BNP had the highest diagnostic value for severe LV hypertrophy and systolic dysfunction compared to cTnT and hs-CRP, irrespective of residual renal function. An analysis based on the best cut-off threshold showed that NT-pro-BNP and cTnT had a negative predictive value of 87.1% and 92.6% for severe LV hypertrophy and 95.4% and 93.2% for systolic dysfunction, respectively. Furthermore, the best cut-off threshold of NT-pro-BNP and cTnT for excluding severe LV hypertrophy and systolic dysfunction was nearly 3-fold higher in anuric patients than in patients with residual renal function. Conclusions. Serum NT-pro-BNP appeared most useful in excluding systolic dysfunction in chronic PD patients followed by cTnT. hs-CRP was not useful in this regard. Residual renal function confounded the interpretation of these biomarkers and reduced their predictive power. A nearly 30% higher cut-off threshold of NT-pro-BNP and cTnT had to be applied in anuric PD patients.