Introduction:In current European guidelines for the management of myocardial infarction after coronary stent placement, there is no consensus on dual antiplatelet therapy (DAPT) ideal duration to prevent stent thrombosis-restenosis without significantly increasing the bleeding risk. Objective: To report the percentage of major bleeding and presence of major cardiovascular events associated with prolonged DAPT in patients recruited at the National Institute of Cardiology, treated with primary percutaneous coronary intervention and stent. Methods: A longitudinal, prospective, observational, non-experimental, descriptive study was carried out. Patients were recruited from November 2016 to December 2017. Results: One hundred and thirty-five patients with a mean age of 57 ± 10 years who completed the three-year follow-up were selected. Obesity and hypertension stood out as the main risk factors. After using DAPT for three years, 3.7% of mortality, 1.48% of major bleeding, and 4.4% of thrombosis-restenosis were recorded. Conclusions: Prolonged use of DAPT would be justified by the high incidence of thrombosis-restenosis, without a significant increase in bleeding risk, as well as a decrease in major cardiovascular events.