Background: It was aimed to compare urine B-type natriuretic peptide (BNP) according to left ventricular systolic dysfunction and to investigate its diagnostic value in heart failure (HF) patients.
Material and methods: A total of 90 HF outpatients (61 men, age 66 +/- 12) and 30 age- and gender-matched controls were studied.
Results: An increase in urine BNP was observed in patients with EF</= 40% compared to EF> 40% (p < 0.0001), and controls (p < 0.0001). Significant correlations between urinary BNP and left ventricular functional parameters were obtained. A multivariate regression analysis was performed and the best model associated with urine BNP included plasma BNP (p < 0.0001), EF (p = 0.02) and LV volume indexes (p < 0.0001). The ROC for detection of EF </= 40% using urine BNP levels showed an area under the curve of 0.74 +/- 0.05, (p < 0.0001). From the ROC curve, the optimal cut-off value (2.30 ng/l) had a 60% sensitivity and 90% specificity. Finally, we performed a binary logistic regression for detection of EF </= 40%, and urine BNP was shown to be a strong predictor with an odds-ratio of 21.
Discussion: Urine BNP levels correlated with left ventricular functional parameters. This biomarker is a useful tool for detecting and diagnosing left ventricular systolic dysfunction in heart failure.