Utility Of Brain Natriuretic Peptide In Differentiating Left Heart Failure From Lung Disease In Patients Presenting With Dyspnea

Objective The goal of this study was to evaluate the utility of measurement of brain natriuretic peptide (BNP) in the diagnosis of left heart failure (LHF) in patients presenting with dyspnea. Methods BNP plasmaconcentrations were measured in 79 in-patients with dyspnea. The main causes of dyspnea were determined according to clinical data including symptoms, physical signs, results of further cardiac and pulmonary tests and responses to special treatments and divided into three categories (LHF, cor pulmonale and pulmonary diseases without cor pulmonale). This gold standard was used to evaluate the diagnostic performance of measurement of BNP. Results Patients with LHF (n = 34) had BNP levels of 615±392 pg/ml, significantly higher than the group of patients with pulmonary disease not accompanied by cor pulmonale (n = 21) whose BNP was 60 ± 46 pg/ml and the group of patients with cor pulmonale (n = 24) whose BNP was 183 ± 145 pg/ml. At a plasma concentration of 210 pg/ml, BNP was an accurate predictor of the presence of LHF (87.4%); Measurements less than this had a high negative predictive value (90.7%). The area under the receiver operating curve, which plotssensitivity versus specificity for BNP levels in the diagnosis of LHF, was 0.93 (0.88-0.99, p<0.001 ) . In multivariate analysis, BNP measurements added significant, independent explanatory power to routine tests in models predicting which patients had LHF. Conclusion BNP blood concentration measurement appears to be a sensitive and specific test to diagnose CHF in patients with acute dyspnea.