NPPB and acute kidney injury: Preoperative NT-proBNP is a prognostic marker for mortality, length of stayin the postoperative intensive care unit, postoperative acute kidney injury,postoperative atrial fibrillation, postoperative low cardiac output,postoperative prolonged mechanical ventilation time, prolongedhospitalization time, unscheduled hospital readmission related to heartproblems, and postoperative heart failure.