Natriuretic peptides predict symptom-free survival and postoperative outcome in severe aortic stenosis

Background - The prognostic value of natriuretic peptides in aortic stenosis (AS) remains unknown. Methods and Results - B-type natriuretic peptide (BNP), N-terminal BNP (NtBNP), and N-terminal atrial natriuretic peptide (NtANP) were determined in 130 patients with severe AS ( mean age, 70 +/- 12 years; mean gradient, 64 +/- 21 mm Hg; valve area, 0.64 +/- 0.15 cm(2)) who were followed up for 377 +/- 150 days. Natriuretic peptides increased with NYHA class and with decreasing ejection fraction (EF). Even asymptomatic patients frequently had elevated neurohormones. Asymptomatic patients who developed symptoms during follow-up had higher BNP and NtBNP levels at entry compared with those remaining asymptomatic ( median for NtBNP, 131 pmol/L [interquartile range, 50 to 202 pmol/L] versus 31 pmol/L [ range, 19 to 56 pmol/L]; P < 0.001). Symptom-free survival at 3, 6, 9, and 12 months for patients with NtBNP <80 versus greater than or equal to80 pmol/L was 100%, 88 +/- 7%, 88 +/- 7%, and 69 +/- 13% compared with 92 +/- 8%, 58 +/- 14%, 35 +/- 15%, and 18 +/- 15%, respectively (P < 0.001). Seventy-nine patients eventually underwent surgery because of symptoms. Considering preoperative neurohormone levels, age, NYHA class, aortic valve area, EF, and presence of coronary artery disease, we found that neurohormones, EF, and NYHA class predicted survival; neurohormones predicted postoperative symptomatic status; and neurohormones and preoperative EF predicted postoperative EF. However, by multivariate analysis, NtBNP was the only independent predictor of outcome. Conclusions - In severe AS, natriuretic peptides provide important prognostic information beyond clinical and echocardiographic evaluation. NtBNP independently predicts symptom-free survival, and preoperative NtBNP independently predicts postoperative outcome with regard to survival, symptomatic status, and left ventricular function. Thus, neurohormones may gain particular importance for timing of surgery in asymptomatic severe AS.