NPPB and atrial fibrillation: The aim of this study was to evaluate the power of pre- and post-operative BNP levels to predict in-hospital major cardiac events (MACE: atrial fibrillation or flutter, acute heart failure, or non-fatal/fatal myocardial infarction) in patients undergoing elective prosthesis orthopedic surgery, and to compare it to that of the RCRI and American Society of Anesthesiology (ASA) class – the most useful scores identified to date.