Prognostic Value of N-Terminal Pro-form B-Type Natriuretic Peptide in Patients With Moderate Aortic Stenosis

Plasma B-type natriuretic peptide (BNP) and its N-terminal pro-form, NT-proBNP, can predict outcomes in patients with severe aortic stenosis (AS). However, their prognostic value in moderate AS is currently unknown. The present study included 261 patients diagnosed with moderate AS (1.0 <aortic valve area ≤1.5 cm²) in 2012 with serum NT-pro BNP level collected within ±3 months of the echocardiographic assessment. Patients were divided into 2 groups according to the median NT-proBNP value (888 pg/dl) and all-cause mortality compared. Median age was 78 years and 64% of patients were male. There were 131 (50%) patients with lower-median NT-pro BNP levels (≤888 pg/dl) and 130 (50%) with higher-median NT-pro BNP levels (>888 pg/dl). During a median follow up of 2.7 years, there were 136 (52%) deaths. Mortality rate was much higher in patients with higher-median NT-pro BNP compared to those with lower-median NT-pro BNP levels (p <0.001). Higher-median NT-pro BNP level was significantly associated with higher mortality rate (hazard ratio 3.11; 95% confidence interval 1.78 to 5.46, p <0.001) even after adjusting for confounders. Aortic valve replacement (AVR) was performed in 82 (31%) patients and median time to AVR was 2.1 years. Patients with higher-median NT-pro BNP had higher mortality rate compared to patients with lower-median NT-pro BNP even after AVR (p <0.01). In conclusion, higher NT-proBNP level is associated with higher mortality rates in patients with moderate AS even among those undergoing AVR.