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

Background: The 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. Methods: We 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. Results: During 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 cm(2)/m(2); 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. Conclusions: In 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.