[Natriuretic peptides in patients with aortic stenosis]

The aim of this research was to, in patients with severe (tight) aortic stenosis (AoS), evaluate a) an association between clinical and some haemodynamic characteristics and natriuretic peptides (ANP, BNP) concentrations and b) usefulness of these hormones in the decision making on the next therapeutic steps.

Echocardiography and 6-minut exertion walking test were performed in 23 consecutive patients (12 men, 11 women; age 67 +/- 7 years) and 20 controls together with ANP and BNP measurements from three plasma samples before, immediately after and 20 minutes after the exertion test.

There was high inter-individual variability in the ANP and BNP concentrations in patients with AoS. All ANP and BNP were significantly higher than in the controls (ANP 1, 2, 3, p < 0.001; BNP 1, 2, 3, p < 0.001). Only the ANP levels increased significantly after the exercise (ANP 1 vs. ANP 2 = 0.011; ANP 2 vs. ANP 3 p = 0.037). We identified significant correlations between aortic peak gradient and BNP 1, 2 (r = 0.821, p < 0.001) and ANP 1, with BNP correlations being stronger. We did not find any correlations with aortic valve area and the left ventricle mass. The hormone levels were non-significantly increased depending on NYHA classification. Exercise did not improve validity ofANP and BNP measurement. Their values had high sensitivity but low specificity in detecting critical AoS.

ANP and mainly BNP helped to exclude severe AoS but they were not useful in detecting lower, orderline gradients. We did not prove ANP and BNP to be significant factors in decision making about the timing of AoS surgery.