Effect of Statins on the Risk of Poststroke Pneumonia: National Population-Based Cohort Study

Purpose: Statins are widely prescribed medications for treatment of dyslipidemia and prevention of cardiovascular disease. Beyond their lipid-lowering property, statins exhibit multiple pleiotropic and antimicrobial effects. We aimed to investigate the effect of statins on the long-term risk of pneumonia after acute ischemic stroke. Methods: This retrospective observational research was performed using South Korean National Health Insurance Service claim data, which consist of population-based random sampling. We included patients discharged with acute ischemic stroke (163 in the ICD10) and no prior history of pneumonia. The primary outcome measure was the occurrence of pneumonia determined based on ICD10 code J09-J18. Treatment with statins during follow-up was collected as a time-dependent variable based on prescription records. Results: A total of 7,001 subjects with acute ischemic stroke and no prior history of pneumonia were included. During the mean 3.96-year follow-up, pneumonia occurred in 1,715 subjects (24.5%). On multivariate time-dependent Cox proportional hazard-regression analyses, significant preventive benefit of treatment with statins against pneumonia was noted (adjusted HR 0.86, 95% CI 0.77-0.97). Compared to no use of statin, adjusted HRs (95% CIs) for current use of low-intermediate high-intensity statins were 0.88 (0.78-0.99) and 0.49 (0.27-0.87), respectively. Conclusion: Our retrospective national cohort study found reduced risk of poststroke pneumonia with statin therapy after acute ischemic stroke. Our study suggests that treatment with statins may have a preventive effect against the common complication of poststroke pneumonia.