Aspirin Plus Clopidogrel Reduces Infection Risk Compared With Aspirin or Clopidogrel Alone in Acute Ischemic Stroke

Activated platelets modulate immune responses. Platelet activation coincides with poststroke immunosuppression, so we hypothesized that platelet inhibition would mitigate immunosuppression and decrease the risk of infectious complications after stroke. In this study, we aimed to evaluate the contribution of platelet inhibition by antiplatelet agents to poststroke infection.

We performed a prospective cohort study of 975 patients with acute ischemic stroke to compare the differences in the risk of infection within 7 days after admission between aspirin alone, clopidogrel alone and aspirin plus clopidogrel. Multivariable Cox proportional hazards regression model was used to assess the association between antiplatelet therapy and poststroke infection.

Among 975 included patients, 578 received aspirin, 98 received clopidogrel, and 299 received both. A total of 113 patients experienced poststroke infection within 7 days after admission. The combination of aspirin and clopidogrel decreased the risk of poststroke infection compared with aspirin alone (hazard ratio [HR], 0.41; 95% confidence interval [CI], 0.22-0.77; P = 0.006), as compared with clopidogrel alone (HR, 0.46; 95% CI, 0.22-1.00; P = 0.050). We found no difference in infection risk between clopidogrel and aspirin. When assessing site-specific infections, a significant difference was observed only in the risk of pneumonia between dual antiplatelet therapy and aspirin alone.

Dual antiplatelet therapy with aspirin and clopidogrel is associated with decreased infection after stroke compared with aspirin or clopidogrel monotherapy. The findings support the net protective effect of aspirin and clopidogrel against poststroke infection.