Peer Reviewed


How Does Aspirin Dose Impact Risk of Cardiovascular Events?

Taking either low or high dose aspirin daily reduces the risk of heart attack, stroke, and death in patients with cardiovascular disease, according to the results of a recent study.

To better understand how aspirin dose impacts the risk of cardiovascular disease events, researchers conducted an open-label, pragmatic study comparing 81 milligrams (mg) to 325 mg of aspirin daily.

Included were 15,076 patients with established atherosclerotic cardiovascular disease, of which 96% (n = 13,527) were already taking aspirin.

The results indicated there were no significant differences in death, hospitalization for myocardial infarction, and hospitalization for stroke between the 81 mg and 325 mg groups. These adverse outcomes occurred in 590 patients (estimated percentage 7.28%) in the 81 mg group, and 569 patients (estimated percentage 7.51%) in the 325 mg group. In the 81 mg group, 53 patients (estimated percentage 0.63%) were hospitalized for major bleeding compared to 44 patients (estimated percentage 0.60%) in the 325 mg group.

Further, patients in the 325 mg group experienced higher rates of dose switching than those assigned to the 81 mg group (41.6% and 7.1%, respectively). Patients in the 325 mg group had fewer median days of exposure to their assigned dose, at 434 days compared to 650 days.

“In this pragmatic trial involving patients with established cardiovascular disease, there was substantial dose switching to 81 mg of daily aspirin and no significant differences in cardiovascular events or major bleeding between patients assigned to 81 mg and those assigned to 325 mg of aspirin daily,” the researchers concluded.


—Leigh Precopio



Jones WS, Mulder H, Wruck LM, et al. Comparative effectiveness of aspirin dosing in cardiovascular disease. NJEM. Published online May 15, 2021. doi:10.1056/NEJMoa2102137