Usefulness of Serial B-type Natriuretic Peptide Assessment in Asymptomatic Aortic Stenosis

Abstract

B-type natriuretic peptide (BNP) level may be a useful prognostic marker for the management of asymptomatic patients with aortic stenosis (AS). The aim of this study was to identify the echocardiographic determinants of BNP changes during follow-up in AS. We studied 61 asymptomatic patients with greater than moderate AS and preserved left ventricular (LV) ejection fraction who underwent rest and exercise Doppler echocardiography with concomitant BNP level measurement at baseline. BNP measurement was repeated after inclusion every 6 months. Patients were divided into 2 groups according to the median of BNP changes during follow-up. According to parameters at rest, patients in the high BNP changes group had significantly higher E/e' ratio. Statistically significant correlations were found between BNP changes and E/e' ratio and indexed left atrial area. According to exercise parameters, patients in the high BNP changes group had significantly lower exercise-induced increase in LV ejection fraction. Statistically significant correlations were found between BNP changes and exercise-induced changes in LV ejection fraction. After adjustment for age, mean aortic pressure gradient, and BNP level at baseline, multivariate analysis identified indexed left atrial area, E/e' at rest, and exercise-induced increase in ejection fraction as independent determinants of BNP changes during follow-up. In conclusion, this study shows that, in asymptomatic patients with preserved LV function and moderate AS, serial BNP measurements may widely vary. Subclinical LV diastolic and systolic dysfunctions are frequently present in patients with higher serial BNP changes.