Objective: To assess the features of asymptomatic patients with acute ST segment elevation myocardial infarction who presents to the emergency with more than 12 h of evolution, and if there is a benefit of an invasive versus medical therapy. Methods: Retrospective, cohort study from January 2012 to December 2014, we compare the outcomes at 6 and 12 months of follow up of the invasive group versus the conservative group. Results: There were no differences in outcomes at 12 months between an invasive versus a conventional strategy; but, looking at the reperfusion state, we found more risk of death and heart failure at 12 months in the no-reperfused group versus the reperfused group (40% versus 0%, OR: 2, CI: 1.2-3.1, p = 0.028 for mortality and 53% versus 0%, OR: 2.2, CI: 1.3-3.98, p = 0.007 for heart failure). Conclusions: In patients with ST elevation acute myocardial infarction with more than 12 h of evolution, the invasive strategy with optimal reperfusion is better than the conservative management or no reperfusion in terms of less mortality and heart failure at 12 months of follow up.