Correlation to NT-ProBNP and remodeling after cardiac surgery

Few data are available on diastolic function in patients with aortic stenosis (AOS) with indication of surgical treatment. A potential correlation between biomarkers and diastolic function has not been established.

The aim of our study was to evaluate diastolic function in patients with AOS waiting for aortic valve replacement (AVR) echocardiographically, and to verify its correlation with serum brain natriuretic peptide (NT-proBNP).

Thirty-one AOS patients (11 male), 21 to 81 years old (mean age, 61±15 years old) were studied before and after AVR. Diastolic function was assessed with Doppler methods: transvalvar mitral flow, tissue Doppler imaging (TDI) and pulmonary venous Doppler (PVD), correlating with serum brain natriuretic peptide (NT-proBNP) before and 6 months after AVR.

Comparing pre to post-operative period, we observed an increase of the left atrial ejection fraction and isovolumetric relaxation time (IRT), and the decrease of the mitral velocity to early diastolic velocity of the mitral annulus ratio (E/E'), the difference between the pulmonary A wave duration and mitral A duration, left atrial systolic volume, left atrial systolic volume index, left ventricular diastolic diameter, left ventricular systolic diameter, end diastolic volume (LVEDV), left ventricular mass index, left ventricular volume and mass index ratio. The values of NT-proBNP were positively correlated to diastolic dysfunction, both before and after surgery.

AOS patients' ventricular diastolic function improved after AVR. The biomarker NT-proBNP might be a useful biomarker of diastolic function in these patients, before and after AVR. NT-proBNP values show a positive correlation with echocardiographic variables that determine diastolic dysfunction, and is a good marker for the characterization of this dysfunction in AOS patients.