Study Population
The study population includes all patients who underwent AVR, either isolated or with coronary artery bypass grafting, at the Queen Elizabeth II Health Sciences Centre (QEII HSC, Halifax, NS, Canada) between 2011 and 2016, inclusively. Patient data was obtained from The Maritime Heart Center Cardiac Surgery (MHC) Registry. The MHC is a detailed clinical database that captures preoperative, intraoperative, and postoperative data from all patients undergoing cardiac surgery from 1995 to present in Nova Scotia, Canada. This database was accessed to identify all patients who had their native valve replaced with Perimount or Trifecta valves in AVR, and who of those patients received reoperations for prosthetic valve failure. Perimount, Perimount RSR, Perimount Magna, and Perimount Magna Ease valves were combined into a single Perimount group. Patients were included of any age, sex, and co-morbidity.