Impact of Antecedent Aspirin Use on Infarct Size, Bleeding and Composite Endpoint in Patients with de Novo Acute Myocardial Infarction

Background: The study aimed to evaluate the impact of antecedent aspirin use on infarct size, bleeding and composite endpoint in patients with de novo acute myocardial infarction. Patients and Methods: A total of 562 consecutive patients with de novo acute myocardial infarction were included in this prospective cohort study. Patients were assigned into two groups based on presence (n=212) and absence (n=350) of prior aspirin use. Primary endpoint was myocardial infarct size, as estimated by troponin I peak. In-hospital mortality, bleeding and composite clinical endpoint including cardiogenic shock, stroke, in-hospital mortality and major bleeding were also evaluated. Results: Although GRACE and CRUSADE scores were higher, troponin I peak was lower in prior aspirin users. This result was maintained after adjustment for baseline ischemic risk profile and other major confounders including MI type and location. Despite high CRUSADE score, there was no increase in major and minor bleeding Minimal bleeding was higher in antecedent aspirin users. When it was adjusted for the CRUSADE score, a similar risk was reported. Conclusion: Patients with de novo acute myocardial infarction using aspirin for primary prevention have an unexpectedly smaller infarct size and similar bleeding rates.