Abstract 14089: Usefulness of N-Terminal Pro B-Type Natriuretic Peptide to Predict Survival in Patient with Low Flow, Low Gradient Aortic Stenosis with Reduced LV Ejection Fraction
Background: We have previously reported that B-type natriuretic peptide (BNP) provides important information for therapeutic decision-making in low-flow, low-gradient, aortic stenosis (LFLG AS) with reduced LV ejection fraction (LVEF). The aim of the present study was to assess the prognostic value of N-terminal pro BNP (NT-proBNP) in this population.
Methods: We prospectively recruited 94 patients with LFLG AS (indexed effective orifice area [EOA] <0.6cm2/m2, mean gradient ≤40mmHg, LVEF ≤40%). All patients underwent dobutamine stress echocardiography and measurements of NT-proBNP.
Results: BNP and NT-proBNP closely correlated (r=0.70; p<0.0001). The independent predictors of NT-proBNP were chronic kidney failure (p=0.005), LVEF (0.01) and AS severity as documented by projected EOA at normal flow rate (0.02). During a follow-up of 2.7 ±2.2 years, there were 38 deaths. After adjusting for age, chronic kidney failure, coronary artery disease, LVEF, AS severity and aortic valve replacement/implantation, patients with NT-proBNP≥1600 pg/ml had a 3.8-fold increased risk of death (95% confidence interval [95CI]: 1.4-11.0; p=0.008). An NT-proBNP level≥1600 pg/ml was also an independent predictor of mortality in the subset of patients treated conservatively (n=47; Hazard Ratio [HR]=9.1; 95CI=2.1-49.5; p=0.0003), and there was a trend toward significance in patients undergoing valve intervention (n=47; Hazard Ratio [HR]=4.7; 95CI=0.9-86.5; p=0.06). Moreover, the increase in NT-proBNP from baseline to 1 year was a predictor of mortality in the whole cohort (HR=1.05 per 10% increase in NT-proBNP; 95CI=1.02-1.10; p=0.003), in patients treated conservatively (HR=1.13 per 10% increase in NT-proBNP; 95CI=1.02-1.26; p=0.03) and in patients undergoing aortic valve intervention (HR=1.06 per 10% increase in NT-proBNP; 95CI=1.01-1.19; p=0.02).
Conclusion: NT-proBNP independently predicts survival in patients with LFLG AS, especially in those patients treated conservatively. Moreover a larger increase in NT-proBNP during follow-up is a predictor of mortality in the whole cohort, as well as in the subsets of patients treated conservatively or with valve intervention.
- © 2012 by American Heart Association, Inc.