B-type Natriuretic Peptide Value for Diagnosis of Congestive Heart Failure in Patients with decreased Renal Function

ABSTRACT

PURPOSE: A number of studies have examined the B-type natriuretic peptide level in dialysis patients and in patients with lesser degrees of renal insufficiency. However, relationships between BNP and renal function are unknown. We sought to assess the diagnostic utility of BNP in differentiating congestive heart failure (CHF) from non-congestive heart failure (non-CHF) in patients with renal insufficiency. METHODS: BNP levels were obtained in 395 patients presenting to our emergency department with dyspnea. Of those 395 patients, 48 patients showed renal insufficiency. Patients transferred to other hospitals and those in a donot- resuscitate state were excluded. RESULTS: In patients with acute renal failure, patients with CHF (n=8) had BNP levels of 360+/-254 pg/ml whereas patients with non-CHF (n=3) had BNP levels of 114+/-103 pg/ml; however, this difference was not statistically significant. In patients with chronic renal failure, patients with CHF (n=22) had BNP levels of 1147+/-635 pg/ml, which was significantly higher than the BNP levels of 459+/-508 pg/ml for patients with non-CHF (n=7) (p=0.01). The area under the receiver operating curve, which plots sensitivity versus specificity for BNP levels in separating congestive heart failure from non-congestive heart failure in patients with chronic renal failure, was 0.805 (p=0.01). The diagnostic accuracy of BNP at a cutoff of 600 pg/ml was 76 %. CONCLUSION: The BNP cut-off value for diagnosis of CHF in patients with chronic renal failure is 600 pg/ml.