Clinical Utility of B-type Natriuretic Peptides in Patients with Heart Failure and Renal Dysfunction

Background: Increased plasma level of B-type Natriuretic peptide (BNP) in chronic kidney disease(CKD) and hemodialysis patients with volume overload and heart failure (HF) is common and decreases during dialysis. BNP and N- terminal pro-hormone B-type Natriuretic peptide (NT-proBNP) are established HF markers, but the concomitant presence of CKD changes their interpretation in a significant manner. Aim: to evaluate the effect of compromised kidney function on the level of BNP in Egyptian patients with CKD and ESRD. Patients and Methods: from June 2011 to June 2012, forty-seven patients (17 CKD patients on regular follow up and 30 ESRD patients on regular hemodialysis) were tested for serum BNP and Echocardiography. Normal range of BNP was calculated from 17 apparently healthy individuals (control group). Results: Plasma BNP was significantly higher in both CKD patients and ESRD patients compared to controls (p<0.001).In CKD group, BNP values did not differ between patients with normal diastolic function and those with impaired diastolic function (p= 0.57). However, in ESRD patients, BNP was significantly higher in patients with impaired diastolic function compared to those with normal diastolic function (p=0.018). A positive correlation was found between diastolic dysfunction and BNP levels in CKD patients (r= 0.45; p=0.013). Our study could not prove that the BNP could provide a certain cutoff value to diagnose ventricular function. BNP value for diagnosis ofleft ventricle systolic dysfunction was set at > 37 pg/ml (p =0.08). While, BNP value for diagnosis of left ventricle diastolic dysfunction was set at >39.1 pg/ml (p= 0.24). Conclusion: BNP can be considered as a diagnostic and prognostic test for diagnosis of HF in CKD and ESRD patients. High plasma level of BNP may indicate the need for further pharmacological treatment for HF.