Antiplatelet therapy and incident cognitive impairment or dementia—a systematic review and meta-analysis of randomised clinical trials

OBJECTIVE: The benefit of antiplatelet therapy in preventing cognitive impairment or dementia is uncertain. We investigated the association between antiplatelet therapy and incident cognitive impairment or dementia in randomised clinical trials. METHODS: We searched PubMed, EMBASE and CENTRAL for randomised clinical trials published from database inception through 1 February 2023. Trials that evaluated the association of antiplatelet therapy with incident cognitive impairment or dementia were included. For single-agent antiplatelet, the control group was placebo. For dual agent antiplatelet therapy, the control group was single-agent monotherapy. A random-effects meta-analysis model was used to report pooled treatment effects and 95% confidence intervals (CIs). The primary outcome was incident cognitive impairment or dementia. Secondary outcomes included change in cognitive test scores. RESULTS: A total of 11 randomised clinical trials were included (109,860 participants). All reported the incidence of cognitive impairment or dementia on follow-up. The mean (SD) age of trial participants was 66.2 (7.9) years. Antiplatelet therapy was not significantly associated with a reduced risk of cognitive impairment or dementia (11 trials; 109,860 participants) (3.49% versus 4.18% of patients over a mean trial follow-up of 5.8 years; odds ratio [OR], 0.94 [95% CI, 0.88–1.00]; absolute risk reduction, 0.2% [95% CI, −0.4% to 0.009%]; I2 = 0.0%). Antiplatelet therapy was not significantly associated with mean change in cognitive test scores. CONCLUSION: In this meta-analysis, antiplatelet therapy was not significantly associated with a lower risk of incident cognitive impairment or dementia, but the CIs around this outcome do not exclude a modest preventative effect.