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

Aortic stenosis (AS) is the most common valvular heart disease. Risk stratification of asymptomatic patients with AS and preserved left ventricular ejection fraction (LVEF) remains challenging. The European Society of Cardiology guidelines have suggested elective B-type natriuretic peptide (BNP)–level measurement for individual risk stratification in asymptomatic AS. The aims of this study were to prospectively describe the individual changes in BNP levels during longitudinal follow-up of asymptomatic patients with AS and preserved LVEF and identify whether these changes were related to the presence of baseline left ventricular (LV) systolic or diastolic dysfunction. Sixty-one patients with asymptomatic, moderate to severe AS with preserved LVEF met inclusion criteria and underwent BNP-level measurement on initial evaluation, along with resting and exercise Doppler echocardiography. BNP-level measurements were repeated after 6 months of follow-up and again at 6-month intervals. Patients were divided into two groups according to the median of serial BNP changes. To identify independent predictors of serial BNP changes, multiple linear regression analysis was used. Mean BNP at baseline was 104 ± 142 pg/mL and significantly increased during follow-up. Multivariate analysis identified indexed left atrial area, E/e′ ratio—an estimate of LV filling pressure—at rest, and exercise-induced increase in ejection fraction as independent determinants of serial BNP changes during follow-up. This study cohort of asymptomatic patients with AS and preserved LVEF demonstrated for the first time that serial BNP changes during follow-up were associated with subclinical LV dysfunction. Patients with higher BNP increases had larger left atrial size and higher E/e′ ratio, two surrogate markers of LV diastolic burden, which is associated with a poor prognosis. Assessing the serial changes in BNP levels may reveal a subgroup of asymptomatic patients with AS with a higher degree of LV diastolic dysfunction, which may precede symptom development and further guide management decisions. Monitoring changes in BNP level might help define the best timing for aortic valve replacement.