Background and purpose: In a randomized controlled trial in Alzheimer's disease (AD), we found a higher number of intracerebral hemorrhages (ICHs) in patients randomized to aspirin treatment. Here, we evaluate the literature on the risk of ICH as a complication in patients with AD treated with aspirin.
Methods: Systematic review and comparison of the occurrence of events over time between the aspirin and control group in each trial using Cox regression analysis. Estimated hazard ratios (HRs) were combined in a pooled HR.
Results: Two randomized controlled trials on aspirin for AD were found. In the Evaluation of Vascular Care in Alzheimer's Disease (EVA) trial (conducted in our center), 4.6% of patients in the group receiving a multicomponent treatment that included aspirin had an ICH (3/65; 95% confidence interval [CI], 1.0 to 12.9) versus 0% in the control group (0/58; 95% CI, 0 to 6.2). In the Aspirin in Alzheimer's Disease (AD2000) trial, these proportions were, respectively, 2.6% (4/156; 95% CI, 0.7 to 6.4) and 0% (0/154; 95% CI, 0 to 2.4). The pooled proportion of ICHs in the aspirin group is 3.2% (7/221; 95% CI, 1.3 to 6.4) versus 0% in the control group (0/212; 95% CI, 0 to 1.7). The pooled HR for an ICH in AD patients using aspirin is 7.63 (95% CI, 0.72 to 81.00; P=0.09).
Conclusions: Although the number of cases in both trials is small, our findings suggest that aspirin use in AD might pose an increased risk of ICH, whereas it has no effect on cognition. If there is an unequivocal cardiovascular indication for aspirin, it should not be withheld in AD patients.