Background to main study question: Cardiac complications are a common cause of morbidity after non-cardiac surgery. Patients with perioperative myocardial injury (both MI, and lower levels of cardiac troponin elevation) experience higher short-term and long-term mortality. They are also at substantially increased risk of additional cardiac and non-cardiac complications. It is therefore plausible that myocardial injury adversely affects quality of life. This study will compare postoperative health-related quality of life of patients who did or did not experience perioperative myocardial injury (defined by troponin-I > 0.07ng/ml) after non-cardiac surgery