While the effect of infection on long-term recurrent risk is unclear, it may still be associated with increased risk for early stroke recurrence in hospitalized patients with acute ischemic stroke, according to study results published in Stroke.
Several factors may increase the risk for infection in the early phase of stroke, including immunodepression, dysphagia, and autonomic dysfunction. Given that infection is common in patients with acute stroke, is associated with inflammatory responses, and may increase likelihood of cardiocerebral vascular events, the goal of the current study was to explore the association between infection and recurrent stroke risk.
The researchers used data from the Chinese Stroke Center Alliance (CSCA) program to evaluate the association between infections during hospitalization and risk for early stroke recurrence. Data from the Third China National Stroke Registry (CNSR-III) were used to explore the association between pneumonia or urinary tract infection during hospitalization and short- (during hospitalization) to long-term (30 days to 1 year after stroke onset) stroke recurrence. These data were also used to ascertain the predictive importance of high-sensitivity C-reactive protein (hs-CRP).
The CSCA cohort included 789,596 patients (median age, 67 years; 62.6% men), of whom 75,434 (9.6%) had an infection during their hospital stays. The risk for early stroke recurrence was higher in patients with an infection compared with that in those without an infection during hospitalization (10.4% vs 5.2%, respectively; adjusted odds ratio [aOR] 1.70; 95% CI, 1.65-1.75; P <.0001).
The CNSR-III cohort included 13,549 patients, of whom 881 (6.5%) had an infection during hospitalization. The statistical analysis revealed that an infection during hospitalization was associated with a higher risk for early recurrent stroke (7.4% vs 3.9%, respectively; aOR, 1.40; 95% CI, 1.05-1.86; P =.02). However, there was no significant association between infection during hospitalization and long-term risk for recurrent stroke (7.2% vs 5.2%; P =.30).
When assessed separately, pneumonia was associated with a higher risk for stroke recurrence, while urinary tract infection was not associated with short- or long-term risk for stroke recurrence.
The association between infections and early stroke recurrence was not entirely dependent on inflammation levels, as determined by hs-CRP levels.
The study had several limitations, including missing data on the date of infection, lack of adjustment for antibiotic treatment, and significant differences in age and the National Institute of Health Stroke Scale score between the included and excluded patients.
“Infection,” concluded the researchers, “was an important risk factor for high risk of early stroke recurrence during hospitalization, but we have not found its sustained effect on long-term recurrence risk in patients with [acute ischemic stroke].”
Xu J, Yalkun G, Wang M, et al. Impact of infection on the risk of recurrent stroke among patients with acute ischemic stroke [published online June 26, 2020]. Stroke. doi:10.1161/STROKEAHA.120.029898