The clinical significance of a urinary B-type natriuretic peptide assay for the diagnosis of heart failure

Abstract

BackgroundThe purpose of this study was to investigate the applicability of urinary B-type natriuretic peptide (BNP) levels to the diagnosis and prognosis of heart failure (HF) by comparing urinary and plasma BNP levels. MethodsUrinary and plasma BNP levels of 160 patients with HF classifiable into NYHA stages I, II, III, or IV, and 30 healthy control subjects were measured using the microparticle enzyme immunoassay (MEIA). The heart function of each patient was examined by ultrasonic cardiogram and classified according to the NYHA standard. ResultsThe levels of urinary and plasma BNP among patients in the HF group were significantly higher than those in the control group. Urinary BNP levels were correlated with plasma BNP levels and NYHA grades of HF and were negatively correlated with LVEF. According to the Cox model multivariate regression analyses on age, gender, heart function class, LVEF, and urinary BNP among patients with post-treatment cardiac events, age and the urinary BNP level were predictors for the independent post-treatment cardiac events. ConclusionsMeasurement of urinary BNP is applicable in clinical diagnosis and prognosis of HF; it provides similar accuracy to plasma BNP in the detection of HF, and it has the advantage of being a noninvasive test.