ABSTRACT
Background: Heart failure (HF) has become a main cardiac problem. Doppler echocardiography has been used to examine left ventricular (LV) diastolic filling dynamics. Limitations of this modality suggest the need for other objective measures of diastolic HF. Aim of the Study: The hypothesis of this study is to assess the utility of N-terminal pro-B type natriuretic peptide (NTproBNP) in the diagnostic evaluation of diastolic HF in comparison with tissue Doppler imaging (TDI) recordings. Methods: A prospective study was carried out between May 2010 and December 2011. Patients with signs and symptoms of HF with normal LV systolic function by 2D-echocardiography were recruited. M-mode and 2-dimensional images, left atrial volume index (LAVI), spectral and TDI of the mitral annulus were obtained for all the patients. NTproBNP levels were measured with a bedside immunoassay. Results: We found linear correlation between NTproBNP levels and grade of diastolic dysfunction (DD), LAVI, ratio of mitral velocity to early diastolic velocity of the mitral annulus (E/E’) [r=0.72, p<0.001]. Patients with elevated left ventricular end diastolic pressure, defined as E/E’>15 (n =18), had the highest NTproBNP levels (3028±2674pg/mL). NTproBNP levels (4146±2887.43 pg/mL) were highest in patients with grade III DD. A receiver operator characteristic curve showed NTproBNP value, 286 pg/mL, the best cut-off for diagnosing diastolic HF with a sensitivity of 89% and a specificity of 100%. Conclusions: Plasma NTproBNP levels can reliably estimate LV filling pressures in patients with HF and normal systolic function which might help to reinforce the diagnosis of “diastolic HF”.