Clopidogrel increases risk of pneumonia compared with aspirin in acute ischemic minor stroke patients

Antiplatelet agents may increase the risk of infections via suppressing platelet-mediated immune response. Here we assessed the contribution of clopidogrel versus aspirin to the development of pneumonia during an acute ischemic stroke admission. A retrospective cohort study was conducted of acute ischemic stroke patients who were admitted to our hospital from 2015 to 2018. Included patients received uninterrupted clopidogrel or aspirin therapy and did not take other antiplatelet agents throughout their stay. The interest outcome was development of pneumonia after stroke. Conditional logistic regression model after propensity score matching and adjusted logistic regression model were used to assess the impact of clopidogrel versus aspirin on post-stroke pneumonia. Among 1470 included patients, 1135 received aspirin and 335 received clopidogrel. Total 149 patients (10.1%) experienced pneumonia during the stroke hospitalization period. No difference was observed between clopidogrel cohort and aspirin cohort in the incidence of post-stroke pneumonia after propensity score matching (relative risk, 1.04; 95% confidence interval (CI) 0.65-1.65; P = 0.875). However, we found that clopidogrel was associated with increased risk of pneumonia compared with aspirin in minor stroke patients (adjusted odds ratio, 2.21; 95% CI 1.12-4.34; P = 0.021), and a statistically insignificant increase of pneumonia in diabetics (adjusted odds ratio, 1.94; 95% CI 0.96-3.94; P = 0.065). Compared with aspirin, clopidogrel is associated with increased pneumonia in minor stroke patients among who the interference of stroke-induced immunosuppression is minimized. Hence, aspirin may be a better choice for minor stroke patients in acute phase of ischemic stroke when pneumonia most frequently occurs.