RESUMO
This study was designed to assess the correlation of brain natriuretic peptide (BNP) levels with cardiac function and to determine the usefulness of BNP as a prognostic marker in patients undergoing cardiac valvular surgery. We measured plasma levels of BNP in 53 patients who had undergone aortic valve replacement (AVR) or aortic and mitral valve replacement (DVR) more than 1 year earlier. These cases were divided into the aortic stenosis (AS) group and an aortic regurgitation (AR) group. Fifty-two patients were in NYHA class I, and 43 (82.7%) of them had plasma levels of BNP above the normal range. There were significant correlations between the plasma levels of BNP and ejection fraction (EF) in both the AS and AR groups (<i>r</i>=-0.460, <i>p</i><0.05; <i>r</i>=-0.529, <i>p</i><0.01). In the AR group, BNP showed significant correlations with LVMI and LVDd (<i>r</i>=-0.469, <i>p</i><0.05; <i>r</i>=0.680, <i>p</i><0.0001), whereas, in the AS group, BNP showed no significant correlation with these factors. The most remarkable finding was the development of heart failure in 3 patients whose plasma levels of BNP were over 80pg/ml, despite remaining in NYHA I during follow-up. We concluded that plasma levels of BNP in a late phase after AVR or DVR can be an excellent biochemical marker for predicting of heart failure and overall prognosis.