NPPB and chronic kidney disease: In the univariate analysis, age, arterial hypertension, chronic kidney disease, troponin T, NT-proBNP, III-IV functional class of the NYHA, heart failure of ischemic etiology, previous peripheral artery disease, previous chronic obstructive pulmonary disease, and a previous history of heart failure admission during the last year were positively associated with 4-year mortality (Table 2).