Funding Acknowledgements: Type of funding sources: None. Introduction: ST-elevation myocardial infarction (STEMI) encompasses a heterogeneous group of patients with distinct prognoses. In worse clinical scenarios with the development of cardiogenic shock (CS), mortality may ascend to 40%. Observatoire Régional Breton sur l'Infarctus risk score (ORBIs) was developed to predict the development of in-hospital CS in patients with STEMI treated with primary percutaneous coronary intervention (PCI). Aim: To validate ORBI score as a predictor of in-hospital mortality (IHM) and long-term outcomes in STEMI. Methods: Retrospective analysis of 296 patients admitted for STEMI and treated with PCI. Patients presenting with CS at admission were excluded. ORBIs evaluates the presence of 11 variables: age >70 years, prior stroke/transient ischemic attack, cardiac arrest upon entry, anterior STEMI, first medical contact-to-PCI delay >90 min, Killip class, heart rate >90/min, a combination of systolic blood pressure <125 mmHg and pulse pressure 10 mmol/L, culprit lesion of the left main coronary artery, and post-PCI thrombolysis in myocardial infarction flow grade <3. The score derived from these variables allowed the classification of patients into four risk categories: low (0-7 points), low-to-intermediate (8-10 points), intermediate-to-high (11-12 points), and high (≥13 points). The Mann-Whitney U test was used for median comparison between groups. Kaplan-Meier survival plots were used to evaluate the predictive power of ORBIs on INM and on 12-month cardiovascular events (12MH). Results: Mean age was 63,9±13 years; 75% were men. 11% had a history of coronary artery disease, and 8% had been submitted to PCI previously. Mean LVEF was 54±12%. 69% had radial artery access. Left anterior descending artery disease was present in 68% of patients. Mean time since beginning of symptoms and hospital admission was 369±492 minutes. Mean duration of hospitalization was 5,68±3,5 days. ORBIs was calculated, and the population was divided into 2 groups: 45% were included in low and low to intermediate risk group (LR) (n=134), and 55% in intermediate to high- and high-risk group (HR). IHM was 3,7%. HR ORBIs was significantly associated with in-hospital mortality (6,2% vs 0,7%; p<0,01; OR 8,8 IC 95% 1,1;69,7). HR ORBIs was also significantly associated with long-term events (mortality and hospitalizations) (15% vs 6%; p<0,01). In univariate analysis, HR group showed significantly different LV ejection fraction (53,6±14,3 vs 61,0±13,1; p<0,01), troponin I at admission (33,3±94,12 vs 15,2±41,9; p<0,01), BNP (424,9±533,4 vs 194,1±170,1; p<0,01), duration of hospitalization (6,1±3,1 vs 5,2±3,9; p<0,01) and age (68,2±12,7 vs 58,9±11,5; p<0,01). Conclusion: Higher ORBIs is associated with increased mortality in patients with STEMI. ORBIs may be a simple predictive model for short and long-term mortality and cardiovascular events in STEMI patients.