Correlation between BNP Levels and Doppler Echocardiographic Parameters of Left Ventricle Filling Pressure in Patients with Chagasic Cardiomyopathy

Abstract

Cardiomyopathy is the most important manifestation of Chagas' disease. Brain natriuretic peptide (BNP) level and Doppler echocardiographic parameters for diastolic dysfunction have shown correlation with left ventricle (LV) filling pressures. The purpose of this study is to compare BNP levels with Doppler echocardiographic parameters in patients with chagasic cardiomyopathy. Forty-three patients (69.8% men; mean age 41.0 +/- 10.4 years) were submitted to an echocardiographic study and 39 had their BNP levels measured. BNP levels increased with the deterioration of the diastolic function (P=0.025). Pulmonary venous flow parameters were correlated with BNP levels, but E/E'ratio (E'measured at the inferior mitral annulus) was the only diastolic parameter that remained an independent predictor of elevated BNP levels in the multivariate analysis. The area under the receiver-operating curve for BNP to detect E/E' >15 was 0.875. A BNP value of 280.4 pg/ml had a sensitivity of 96% and a specificity of 75% for predicting E/E' >15. In a group of patients with chagasic cardiomyopathy, BNP levels correlated with diastolic function patterns regardless of systolic function. The E/E'ratio (inferior wall) was the only isolated parameter of diastolic function that was independently associated with BNP levels.