Background and Purpose: Antecedent infections have been identified as possible risk factors and triggers for stroke, while infections after stroke lead to worse outcomes. The impact of infections present at the time of admission (IPOA) has not been well characterized. We hypothesized that IPOA would be associated with stroke severity and outcomes in young stroke patients.
Methods: A retrospective review of consecutive ischemic stroke patients aged 18-40 years admitted between January 2008 and June 2014 was performed. IPOA were defined as present if the infection was diagnosed within the first 24 hours of admission. The primary outcomes were stroke severity using the National Institutes of Health Stroke Scale (NIHSS) and poor functional outcome at discharge (modified Rankin Scale (mRS) 3-6)).
Results: Of 235 patients, 41 (17.4%) had IPOA. Patients with IPOA were more likely to be women (87.8% vs. 51.0%; p<0.0001), younger (30 vs. 34 years; p=0.0317) and to have a higher NIHSS (median 4 vs. 2; p=0.029). In the overall sample, IPOA, age, and female sex were associated with poor outcome. The effect of age on the relationship between IPOA and outcomes appeared to be an interaction, however, the sample size is small; therefore analyses stratified on age were conducted to assess the relationship between IPOA and outcomes. Among patients 18-30, those with IPOA had NIHSS scores 6 points higher than those without IPOA after adjusting for age and sex (p=0.0039), whereas there was no relationship between IPOA and NIHSS in patients > 30 years. In patients 18-30, after adjusting for age, sex, and NIHSS, IPOA was associated with a greater odds of poor outcome (OR 3.69, 95%CI 1.20-11.3); NIHSS was not associated with mRS 3-6 (OR 1.00, 95%CI 0.99-1.01). IPOA was not significantly associated with poor outcome after adjusting for age, sex and NIHSS in patients >30 years (OR 1.29, 95%CI 0.48-3.51).
Discussion: Infections present at time of admission in young stroke patients are closely associated with NIHSS and subsequent poor outcomes at discharge. Further studies are needed to understand the role of infection and whether infections moderate the effect of stroke severity on stroke outcomes in young patients.