Hospitalized Infection as a Trigger for Acute Ischemic Stroke

Abstract

Background and Purpose Acute triggers for ischemic stroke, which may include infection, are understudied, as is whether background cardiovascular disease (CVD) risk modifies such triggering. We hypothesized that infection increases acute stroke risk, especially among those with low CVD risk. Methods Hospitalized strokes and infections were identified in the Atherosclerosis Risk in Communities (ARIC) cohort. A case-crossover design and conditional logistic regression were used to compare hospitalized infections among stroke patients (14, 30, 42, and 90 days before stroke) with corresponding control periods 1 year and 2 years prior. Background CVD risk was assessed at both visit 1 and the visit most proximal to stroke, with risk dichotomized at the median. Results A total of 1,008 adjudicated incident ischemic strokes were included. Compared to control periods, hospitalized infection was more common within 2 weeks before stroke (14 day odds ratio (OR) = 7.7 (2.1, 27.3)); the strength of association declined with increasing time in the exposure window before stroke (30 day OR = 5.7 (2.3, 14.3), 42 day OR = 4.5 (2.0, 10.2), and 90 day OR = 3.6 (2.1, 6.5)). Stroke risk was higher among those with low compared with high CVD risk, with this interaction reaching statistical significance for some exposure periods. Conclusions These results support the hypothesis that hospitalized infection is a trigger of ischemic stroke, and may explain some cryptogenic strokes. Infection control efforts may prevent strokes. CVD preventive therapies may prevent strokes if used in the peri-infection period but clinical trials are needed.

Influenza‐like illness as a trigger for ischemic stroke

“…A composite measure of chronic infection assessed by serologies against several common bacterial and viral infections was associated with increased long‐term stroke risk in the Northern Manhattan Study 6. In case‐crossover analyses from both the Cardiovascular Health Study and the Atherosclerosis Risk in Cardiovascular Disease Study, recent hospitalization for infection was associated with increased risk of stroke 7, 8. The association between infection and stroke diminishes over time, however.…”

Endodontic therapy and incident cardiovascular disease: The Atherosclerosis Risk in Communities (ARIC) study

“…6 Other research on infection and CVD has found that infection is a stronger CVD risk factor among those with low background CVD risk compared to those with elevated background CVD risk. 24 It is possible EI was a risk factor for CVD among ARIC participants when they were young with an otherwise low background CVD risk when they were studied by Caplan et al, but not among ARIC participants when they are older with an elevated background CVD risk profile, as in the present study. However, our analyses stratified by median age at CVD event (i.e., 77 years) failed to reach statistical significance.…”

“…An earlier study by Caplan et al in a different study population found that among those ≤40 years old, endodontic lesions were significantly associated with incident CHD ( p < 0.05) but found no association among those >40 years old . Other research on infection and CVD has found that infection is a stronger CVD risk factor among those with low background CVD risk compared to those with elevated background CVD risk . It is possible EI was a risk factor for CVD among ARIC participants when they were young with an otherwise low background CVD risk when they were studied by Caplan et al, but not among ARIC participants when they are older with an elevated background CVD risk profile, as in the present study.…”

Hospitalization with infection and incident venous thromboembolism: The ARIC study

“…Case periods were selected to address the timing and duration of VTE risk after infection similar to study methodology used by Cowan et al 26 and Elkind et al 27 We employed two exposure classification schemes. First, exposure was dichotomized as hospitalization with infection or no hospitalization with infection (referent) which includes participants not hospitalized and those with hospitalizations that did not include an infection.…”