BACKGROUND There is increasing evidence that low-risk patients with ST Elevation Myocardial Infarction (STEMI) can be safely discharged at ≤72hours from admission. Assessment of patients as low-risk is based on clinical judgement and no consistent criteria are used in practice. At this time, assumption is made that low-risk patients are predominantly undergoing early discharge, but no definitive data exists that categorizes these patients in our institution (Tertiary Care Center). The objective of the study is to describe the patients undergoing early discharge and to determine if they meet the early discharge criteria that is recommended in guidelines. METHODS AND RESULTS The Zwolle score was retrospectively applied to all ST elevation myocardial infarction patients treated with primary PCI between January 2019 and January 2021 at a large Canadian teaching hospital. The Zwolle index is an externally validated risk score that has been used to identify low-risk primary PCI patients who can safely be discharged from the hospital within 48 h to 72 h. The length of stay was defined as the time (in days) from first balloon inflation to the date and time of discharge. Data were collected on 1255 patients. 622 of these patients were repatriated to other hospitals and 570 patients were directly discharged from our institution. Of the patients discharged directly, 426 (75%) underwent early discharge and 144 (25%) were late discharge. Early discharge patients tended to be younger (63±11.4, p CONCLUSION This study provided significant insight into the characteristics of patients currently being discharged from a tertiary cardiac care unit. Some high-risk patients are undergoing early discharge for which the early discharge criteria was not validated. More data is needed to determine if there is a signal of potential adverse outcome in this high-risk population.