To investigate the diagnostic value of serum brain natriuretic peptide (BNP)/N terminal pro-BNP (NT-proBNP) in elderly patients with heart failure (HF).

A total of 169 elderly patients with chronic diseases admitted to our department from January 2017 to December 2019 were selected. According to New York Heart Association (NYHA) cardiac function classification, the patients were divided into Group A (No HF), Group B (NYHA Ⅰ+ Ⅱ), and Group C (NYHA Ⅲ+ Ⅳ). Left ventricular ejection fraction (LVEF) was detected by Doppler ultrasound. The 6-minute walking distance (6MWT), serum BNP, NT-proBNP, C-reactive protein (CRP), calcitonin, creatinine, urea nitrogen, globulin, albumin, and cystatin C were measured on admission. The differences of serum BNP/NT-proBNP were compared by ANOVA in patients with different cardiac function grades and the relationship between BNP/NT-proBNP and the above indexes was analyzed with Pearson′s correlation analysis. Each group was divided into sub-groups according to different renal functions or whether or not they were combined with infections, and the differences of BNP/NT-proBNP in HF combined with renal insufficiency or infection were further compared.

With the decrease of cardiac function, BNP/NT-proBNP decreased gradually (0.252±0.065, 0.221±0.062, and 0.195±0.071, F=9.807, P<0.001), and the ratio was significantly correlated with LVEF and 6MWT (r=0.300, P<0.001; r=0.230, P=0.003). In the three groups, the BNP/NT-proBNP level did not differ significantly between the uninfected patients and those with combined infection P>0.05). In group B and C, patients with a glomerular filtration rate (GFR)<30 ml/(min?1.73 m²) had significantly lower BNP/NT-proBNP than those with a GFR≥30 ml/(min?1.73 m²) (Group B: 0.128±0.110 vs 0.255±0.056, t=6.578, P<0.001; Group C: 0.135±0.046 vs 0.199±0.077, t=2.819, P=0.007). However, when the patients with a GFR<30 ml/(min?1.73 m²) were excluded for further study, it was found that in the three groups, the differences of BNP/NT-proBNP in patients with a GFR<60 ml/(min?1.73 m²) were not statistically significant compared with those with a GFR≥60 ml/(min?1.73 m²) (P>0.05).

BNP/NT-proBNP plays an important role in the diagnosis and prognosis of HF in elderly patients.