The Association of Discharge Aspirin Dose With Outcomes After Acute Myocardial Infarction: Insights From the TRANSLATE-ACS Study
Background—Aspirin is the most widely used antiplatelet drug post-myocardial infarction (MI), yet its optimal maintenance dose after percutaneous coronary intervention (PCI) with stenting remains uncertain.
Methods and Results—We compared outcomes of 10,213 MI patients who underwent PCI and were discharged on dual antiplatelet therapy at 228 United States hospitals in the TRANSLATE-ACS study from 2010-2012. Major adverse cardiovascular events (MACE) and bleeding within 6 months post-discharge were compared between high- (325 mg) and low-dose aspirin (81 mg) using regression models with inverse probability-weighted propensity adjustment. Overall, 6,387 patients (63%) received high-dose aspirin at discharge. MACE risk was not significantly different between groups (high vs. low: unadjusted 8.2% vs. 9.2%; adjusted hazard ratio 0.99, 95% confidence interval [CI] 0.85-1.17). High-dose aspirin use was associated with greater risk of any Bleeding Academic Research Consortium (BARC)-defined bleeding events (unadjusted 24.2% vs. 22.7%; adjusted odds ratio [OR] 1.19, 95% CI 1.06-1.33), driven mostly by minor BARC type 1 or 2 bleeding events not requiring hospitalization (unadjusted 21.4% vs. 19.5%; adjusted OR 1.19, 95% CI 1.05-1.34). Bleeding events requiring hospitalization were similar by aspirin dosing groups (unadjusted 2.8% vs. 3.2%, adjusted OR 1.22, 95% CI 0.87-1.70). Similar associations were observed in landmark analyses accounting for aspirin dosing change over time, and across subgroup analyses by age, sex, baseline aspirin use, and type of ADP receptor inhibitor (clopidogrel vs. prasugrel/ticagrelor).
Conclusions—Among PCI-treated MI patients, high maintenance dose aspirin was associated with similar rates of MACE, but greater risk of minor bleeding compared with those discharged on low-dose aspirin.
- Received December 17, 2014.
- Revision received April 25, 2015.
- Accepted May 14, 2015.