What Is the Risk-Benefit Tradeoff of Acute Aspirin Use for Patients With AFib?

The tradeoff between increased risk of bleeding and reduced risk of ischemic events may be equal among certain patients with atrial fibrillation (AF) who take aspirin for up to 30 days, according to research presented during the 2020 American College of Cardiology/World Congress of Cardiology virtual meeting.1

The finding comes from a post-hoc analysis2 of the AUGUSTUS trial. The trial had included 4614 patients with AF and recent acute coronary syndrome (ACS) and/or had percutaneous coronary intervention (PCI) who were on a P2Y12 inhibitor. The patients had been randomly assigned to receive either aspirin or placebo and to open-label apixaban or vitamin K antagonist (VKA) for 6 months.

The patients—all of who had a high risk of bleeding and ischemic event—had a median age of 71 years.

“In a post-hoc analysis, we compared the risk of 3 composite bleeding outcomes and 3 composite ischemic outcomes from randomization through 30 days and from 30 days to 6 months with apixaban and VKA and with aspirin and placebo,” the researchers wrote.

For both timeframes, apixaban yielded a lower or similar risk of bleeding and ischemic outcomes compared with VKA.

From randomization to 30 days, aspirin caused more severe bleeding (absolute risk difference, 0.97%) and fewer severe ischemic events (absolute risk difference, -0.91%) than placebo.

From 30 days to 6 months, the risk of severe bleeding was higher with aspirin use than placebo (absolute risk difference, 1.25%). The risk of severe ischemic events with aspirin vs placebo during this timeframe was similar (absolute risk difference, -0.17%).

“In patients with AF and recent ACS and/or PCI receiving a P2Y12 inhibitor, apixaban is preferred over VKA. After 30 days, aspirin continued to increase bleeding without significantly reducing ischemic events,” the researchers concluded. “These results inform shared, patient-centric, decision making regarding the ideal duration of use of aspirin after an ACS and/or PCI in patients with AF receiving oral anticoagulation.”

—Colleen Murphy


  1. AUGUSTUS: aspirin associated with equally increased bleeding, reduced ischemic risk for 30 days in AFib patients. [News release]. American College of Cardiology; March 29, 2020. Accessed March 31, 2020.
  2. Alexander JH, Wojdyla D, Vora AN, et al. The risk / benefit tradeoff of antithrombotic therapy in patients with atrial fibrillation early and late after an acute coronary syndrome or percutaneous coronary intervention: insights from AUGUSTUS [published online March 29, 2020]. Circulation. doi:10.1161/CIRCULATIONAHA.120.046534