Impact of Serial B-Type Natriuretic Peptide Changes for Predicting Outcome in Asymptomatic Patients With Aortic Stenosis

Abstract

BackgroundThe aim of this study was to determine the impact on the outcome of serial B-type natriuretic peptide (BNP) changes during follow-up in asymptomatic patients with ≥ moderate aortic stenosis (AS) and preserved left ventricular ejection fraction. MethodsWe prospectively screened 69 patients who underwent comprehensive transthoracic echocardiography, BNP level measurement at baseline and after every 6 or 12 months. Annualized BNP changes were calculated as the difference between the last and baseline BNP measurements divided by the duration of follow-up. The primary endpoint was the occurrence of symptoms, aortic valve replacement, or cardiovascular death. ResultsDuring a follow-up of 30 ± 19 months, 43 patients experienced a cardiac event. These patients were significantly older (73 ± 9 vs 65 ± 16 years; P = 0.010), had more often dyslipidemia (79% vs 42%; P = 0.038), more severe AS (peak velocity: 3.9 ± 0.6 vs 3.5 ± 0.6 m/s; P = 0.002), larger indexed left atrial area (10.2 ± 2.5 vs 8.7 ± 1.9 cm2/m2; P = 0.006), and a higher increase in annualized BNP (+90 ± 155 vs +7 ± 49 pg/mL/y; P = 0.010). Patients with higher annualized BNP changes (> 20 pg/mL/y) had a significantly lower cardiac event-free survival (1 year: 63 ± 8% vs 97 ± 3%; 3 years: 31 ± 8% vs 68 ± 8%; P < 0.001). Using the multivariate Cox proportional hazards model, higher annualized BNP changes were significantly associated with increased risk of cardiac events (hazard ratio: 2.73, 95% confidence interval: 1.27-5.86; P = 0.010) after adjustment for age, dyslipidemia, and echocardiographic parameters. ConclusionsIn asymptomatic patients with AS and preserved left ventricular ejection fraction, the use of serial BNP changes may help to anticipate development of class I indication for aortic valve replacement.