Impact of infections on long-term outcome after severe middle cerebral artery infarction

Post-stroke infections are the most important complications after acute stroke, accounting for almost 20% of in-hospital deaths and poor functional outcomes at discharge. Little is known about long-term effects of post-stroke infections on outcome. Here, we studied the impact of infections on long-term outcome in 64 patients which had suffered from severe middle cerebral artery infarction. Mean follow-up time in the survivors was 6.5 ± 0.9 years. Structured telephone interviews were performed to assess the patients' current functional outcome. Where re-contacting was not successful, vital status of the patients was requested at the registration office of Berlin. Multiple logistic regression analysis identified three independent risk factors associated with mortality: infections within the first 11 days after stroke, age>64 years, and female sex. Among surviving patients, functional outcome measured by Barthel Index was influenced by infections and immunocompetence measured by levels of monocytic HLA-DR expression on day 3 after stroke. In conclusion, the occurrence of post-stroke infections is the most important predictor of poor long-term outcome in this cohort of patients. Our observation warrants prospective trials on prevention or early treatment of post-stroke infections in order to improve long-term outcome after stroke.