Predictive Value of Admission N-Terminal Pro-B-Type Natriuretic Peptide and Renal Function in Older People Hospitalized for Dyspnoea

Abstract

Background. We investigated the relationship between NT-pro-BNP, glomerular filtration rate (GFR), and all-cause mortality rates in a cohort of older people discharged from an internal medicine unit after admission for dyspnoea.Patients and Methods. NT-pro-BNP was evaluated in serum samples of 134 patients aged 80 ± 6 years who presented to a single academic centre with worsening dyspnoea. History data and anthropometric, clinical, and biochemical parameters including GFR were collected at the time of admission. 119 out of 134 were discharged alive from hospital and were included in the follow-up of 779 ± 370 days.Results. 35 out of 119 subjects died after a follow-up of 266 ± 251 days. Cox proportional hazards model showed that GFR and Ln (NT-pro-BNP) were predictors for all-cause mortality with estimated hazard ratios of 0.969 (95% confidence interval: 0.950–0.988;P=0.001) and 2.360 (95% confidence interval: 1.208–4.610;P=0.012), respectively. Patients characterized by high NT-pro-BNP levels and GFR ≥ 60 mL/min/1.73 m2showed a dramatic reduction in survival duration compared with the groups with different combinations of the two variables (P=0.008).Conclusions. In the elderly, NT-pro-BNP and GFR are predictors of all-cause mortality after admission because of dyspnoea. Since the fact that subjects with high NT-pro-BNP and GFR≥60 mL/min/1.73 m2exhibited a reduced survival, high admission NT-pro-BNP suggests future negative outcome.