187 patients (>60 years old) undergoing emergency orthopaedic surgery and participating in a randomized controlled trial were monitored in this observational study. The purpose of this analysis was to determine whether both pre- and postoperative levels of the inactive form of brain natriuretic peptide (N-terminal pro-BNP) and angiotensin-converting enzyme 2 (ACE-2) significantly predict the incidence of cardiac events in hospital and at 1 year. Results indicated that preoperative N-terminal pro-BNP levels of 741 pg/mL or greater, as well as postoperative NT-proBNP levels of 1,064 pg/mL or greater, significantly predicted cardiac events in hospital and at 1 year. However, the same could not be said for either pre- or postoperative angiotensin-converting enzyme 2 (ACE-2) levels.