Between 8.5% and 40% of patients with acute myocardial infarction present late after symptom onset, no longer being eligible for thrombolysis.Despite efforts to reduce time to presentation, recent studies have demonstrated that time-to-arrival has not changed.The lack of efficacy of thrombolysis in patients with acute MI presenting > 12 hours after symptom onset may be a reason why current guidelines oppose reperfusion therapy in this setting.Several findings suggest, however,that reperfusion therapy may be beneficial even among these patients. First, recent studies have shown that viable salvageable myocardium exists even after >12 hours of severe ischemia. Second, previous studies have not only demonstrated that PCI is better than thrombolysis in patients with acute MI,but also that the time window of efficacy for PCI may be wider than that for thrombolysis.Third, observational studies suggest that PCI is effective even when performed after 12 hours from symptom onset in patients with acute MI. The goal of our trial was to assess whether an invasive strategy based on PCI with stenting is associated with reduction of infarct size in patients with acute STEMI presenting > 12 hours after symptom onset compared with a conventional conservative treatment strategy.