NPPB and heart failure: In 2017, Voors (47) developed and validated a mortality risk model based on the clinical data of patients with heart failure with preserved ejection fraction from 11 European countries in the BIOSTAT-CHF and showed that advanced age, higher BUN and NT-proBNP, lower hemoglobin, and no β-blocker were the five variables with the strongest prediction effect on mortality, among which age, BUN, NT-proBNP, and β-blockers were consistent with the results of this paper.