Low-dose aspirin has long been used in stroke prevention. In older adults, however, the balance between the reduction of ischemic stroke events and the increased risk of intracranial bleeding has yet to be established.

For this study, the researchers wanted to measure these increased risks in healthy adults who received a daily dose of 100mg enteric-coated aspirin (low-dose).

They conducted a secondary analysis of data obtained from Aspirin in Reducing Events in the Elderly (ASPREE). The data sample included older adults free of symptomatic cardiovascular disease who had been followed up for a median (IQR) of 4.7 (3.6-5.7) years. The analysis was completed from August 2021 to March 2023.
 

• Of the 19114 participants,  56.4% were females with a median age of median age of 74 years.

• 9525 individuals received aspirin, and 9589 individuals received placebo.
   

• Aspirin did not produce a statistically significant reduction in the incidence of ischemic stroke

• However, a statistically significant increase in intracranial bleeding was observed among individuals assigned to aspirin (108 individuals [1.1%]) compared with those receiving placebo (79 individuals [0.8%]; HR, 1.38; 95% CI, 1.03-1.84).

  • This occurred by an increase in a combination of subdural, extradural, and subarachnoid bleeding with aspirin compared with placebo (59 individuals [0.6%] vs 41 individuals [0.4%]; HR, 1.45; 95% CI, 0.98-2.16).

• Hemorrhagic stroke was recorded in 49 individuals (0.5%) assigned to aspirin compared with 37 individuals (0.4%) in the placebo group (HR, 1.33; 95% CI, 0.87-2.04).

 
These findings may have particular relevance to older individuals prone to developing intracranial bleeding after head trauma.