Nickan Research Institute Immunopathologia Persa 2423-8015 6 1 2020 01 01 Safety and efficacy of high-dose versus low-dose aspirin in individuals with ST elevation myocardial infarction undergoing primary percutaneous coronary intervention: A randomized clinical trial e05 e05 10.15171/ipp.2020.05 EN Abdolhossien Emami Sigaroudi https://orcid.org/0000-0001-9215-4071 Arsalan Salari https://orcid.org/0000-0002-5821-6176 Mohadeseh Poursadeghi Fatemeh Moaddab Seyedeh Fatemeh Mirrazeghi Fardin Mirbolouk Journal Article 10.15171/ipp.2020.05 2019 10 13 2019 12 08 Introduction: Aspirin is the most frequently used antiplatelet therapy after percutaneous coronary intervention (PCI). Yet, the optimal daily dose of aspirin is unanswered. Objectives: We aimed to compare the effect of high-dose versus low-dose aspirin in a randomized trial of patients with ST-segment elevation myocardial infarction (STEMI) undergoing PCI. Patients and Methods: In a double-blind randomized trial, 175 patients with STEMI were randomly assigned to high-dose or low-dose aspirin. The primary efficacy outcome was major adverse cardiovascular events (MACE) as a composite endpoint of death, myocardial infarction, stroke and revascularization procedures. The primary safety endpoint was major bleeding. Results: Totally 90 and 85 patients were assigned to high-dose and low-dose aspirin, respectively. The incidence rate of MACE was 13.1 and 10.1 per 100 person year in high-dose and low dose aspirin, respectively. There was no significant difference between high-dose and low-dose aspirin in terms of efficacy (Adjusted hazard ratio: 0.85, 95% CI=0.29-2.45) and safety outcome (Adjusted hazard ratio: 1.65, 95% CI=0.41-6.69). Conclusion: Efficacy and safety outcomes were not significantly different between high-dose and low-dose aspirin.