Is B-type Natriuretic Peptide(BNP) Measurement Useful Test for Diagnosing Systolic Heart Failure in Patients with Moderate to Severe Renal Insufficiency?

ABSTRACT

BACKGROUND AND OBJECTIVES: Plasma B-type natriuretic peptide (BNP) can be increased in patients with renal insufficiency (RI). The aim of this study was to evaluate the diagnostic value of BNP for systolic heart failure (HF) in patients with moderate to severe RI. SUBJECTS AND METHODS: Between Aug 2002 and May 2004, 433 patients found to have systolic HF or moderate to severe RI were included. The patients were divided into 3 groups (group I; only HF, group II; only RI, group III; HF and RI). The severity of RI was graded according to the calculated creatinine clearance (Ccr); moderate 30< or =Ccr<60, severe 15< or =Ccr<30 or end stage renal disease (ESRD) Ccr<15 mL/min. RESULTS: The mean age of the patients was 67.6+/-12, and 49% were male. There were significant differences in the mean BNP levels between group III and the other two groups (p<0.001); group I (n=65, 837.3+/-884), group II (n=137, 1049.4+/-1332) and group III (n=231, 1738.3+/-1501 pg/mL). A weak negative correlation was note between BNP and Ccr (r=-0.335, p<0.001) in patients with RI. As the renal function deteriorated, the mean BNP of groups II and III was found to be elevated (moderate 625.5+/-574, 1183.0+/-1056; severe 760.5+/-1211, 2205.4+/-1470; ESRD 2157.6+/-1831, 3209.9+/-1900 pg/mL, p<0.05), with the mean BNP of group III being higher than that of group II for each grade (p<0.05). From the ROC curve, the optimal cut-off point of BNP for the diagnosis of systolic HF in patients with RI was 829 pg/mL (accuracy 68%, sensitivity 66% and specificity 70%, p<0.001). CONCLUSION: In the case of patients with moderate to severe RI, a higher BNP cut-off point for the diagnosis of systolic HF and a relatively lower diagnostic accuracy of BNP should be considered.