“Accumulated data suggest that low-dose aspirin after myocardial infarction (MI) may offer similar efficacy to higher dose aspirin with reduced risk of bleeding,” explained Hurst M. Hall, MD, of the University of Texas, and colleagues. Their findings were published in Circulation: Cardiovascular Quality and Outcomes.
To examine contemporary aspirin dosing patterns, the investigators analyzed data from 221,199 patients with myocardial infarction (MI) from 525 hospitals in the United States.
Of the patients with acute MI, 60.9% were discharged on high-dose aspirin (325 mg), 35.6% on low-dose aspirin (81 mg) and 3.5% on other doses between January 2007 and March 2011.
At discharge, 73% of patients treated with percutaneous coronary intervention, and 44.6% of those managed medically were prescribed high-dose aspirin at discharge. Of the 9,075 patients, 44% discharged on aspirin, thienopyridine, and warfarin were prescribed high-dose aspirin.
More than half (56.7%) of patients with an in-hospital major bleeding event were also discharged on aspirin. Across participating center there was a 25-fold variation in the proportion of prescribed high-dose aspirin at discharge.
“Wide variability in the proportional use of high-dose aspirin across centers suggests significant influence from local practice habits and uncertainty about appropriate aspirin dosing,” concluded the researchers.