Primary Prevention of Ischemic Heart Disease With Aspirin Reduces the Severity of Clinical Presentation

Introduction: The USPSTF has recommended the use of preventive aspirin in all subjects aged 55-79 years without known heart disease when the potential benefit of a reduction in myocardial infarction outweighs the potential harm of bleeding. However, some studies have suggested that for women, the risks of aspirin may outweigh the benefit. Hypothesis: To investigate whether the risk of initial presentation of coronary heart disease with STEMI is lower in aspirin users and, if so, to assess the role of age and concomitant medications and procedures in the reduction of risk. Methods: We analyzed clinical characteristics and outcomes of patients without preexisting CVD that were enrolled in 41 hospitals referring data to the ISACS-TC registry (NCT01218776) from January 2010 to January 2018. Primary end points included rates of STEMI at clinical presentation and adjusted 30-day mortality. For the safety analysis, hemorrhagic events, consisting of gastrointestinal bleeding, hemorrhagic stroke, and bleeding from any other sites, were also analyzed. Estimates were obtained using logistic regression models. Results: There were 1098 subjects with a mean (SD) age of 66 (11.3) years in the aspirin group and 8978 subjects with a mean (SD) age of 60.3 (12.0) years in the no-aspirin group included in the study. After multivariable adjustment for age, sex, kidney function and risk factors, aspirin therapy reduced clinical presentation with STEMI in the protocol cohort (OR, 0.52; 95% CI, 0.46-0.60) with no heterogeneity of efficacy in subgroup analyses stratified by each of these factors (all interaction P>0.05). Similar treatment effects with aspirin therapy were found when concomitant medications were included as dummy variables in sequential logistic analyses (OR, 0.62 for statins, 0.59 for ACE inhibitors and 0.61 for beta-blockers) (Figure 1.). Bleeding events occurred in 8 patients (1.4%) in the aspirin group and 88 (2.4%) in the no-aspirin group (P=0.12), and the incidence of hemorrhagic stroke was not different between groups (P=0.28). Conclusions: Aspirin reduces the risk for STEMI without increasing risk for gastrointestinal bleeding in women and men in a primary prevention setting. These data support the routine use of aspirin as recommended by the USPSTF.