Objective: To evaluate the diagnostic value of NT-proBNP in patients with aortic stenosis (AS), analyze the relation of NT-proBNP to NYHA functional class and echocardiographic findings.
Methods: Measured the whole venous blood of NT-proBNP with enzyme linked immuno sorbent assay in 40 aortic stenosis patients (AS group) and 76 normal subjects (control group). We assessed the diagnostic value of NT-proBNP for aortic stenosis, and related NT-proBNP to clinical NYHA functional class and echocardiographic findings.
Results: Compared to controls, NT-proBNP levels had significantly higher in patients with aortic stenosis (P < 0.01). The level of NT-proBNP was gradually and significantly increased with the NYHA functional II, III and IV class compared to controls (all P < 0.01). NT-proBNP was significantly (3.5 times) higher in mild/moderate stenosis group than that in control group (2.95 ± 0.48 vs 2.63 ± 0.10, P < 0.05), and was significantly (6.0 times) higher in severe stenosis group than that in control group (3.16 ± 0.50 vs 2.63 ± 0.10, P < 0.01). LVMI was significantly (1.7 times) higher in mild/moderate stenosis group than that in control group (169 ± 51 vs 100 ± 22, P < 0.01), and was significantly (2.1 times) higher in severe stenosis group than that in control group (212 ± 86 vs 100 ± 22, P < 0.01). The NT-proBNP values of 1150 ng/L and 1356 ng/L were determined as the best cutoff values for the diagnosis of patients with mild/moderate (AUC = 0.657, P < 0.05) and severe aortic stenosis (AUC = 0.848, P < 0.01), the sensitivity, specificity and accuracy were 61.11% and 77.30%, 69.74% and 96.10%, 68.09% and 91.80%. Log (NT-proBNP) was significantly positively related with LVEDD, LVMI and mean transvalvular pressure gradient (MTPG) (all P < 0.05), and negatively related with LVEF (P = 0.01) in univariate analysis. In multiple regression analyses, NYHA functional class, LVEF and Log (MTPG) was independently associated with NT-proBNP.
Conclusion: NT-proBNP is valuable for the diagnosis of patients with aortic stenosis. NT-proBNP has correlation with the heart function and severity of the aortic stenosis.