Influenza‐like illness as a trigger for ischemic stroke

Abstract

ObjectiveWe hypothesized that ILI is associated with risk of incident stroke, and that the risk would be highest closest in time to the event.MethodsThis case‐crossover analysis utilized data obtained from the California State Inpatient Database of the Healthcare Cost and Utilization Project (HCUP). The outcome of interest was ischemic stroke. Exposure was defined as a visit to the emergency department or hospitalization for influenza‐like illness (ILI) 365, 180, 90, 30, or 15 days before stroke (risk period) or similar time intervals exactly 1 or 2 years before stroke (control period). Conditional logistic regression was used to calculate the odds ratio and 95% confidence interval (OR, 95% CI).ResultsIn 2009, 36,975 hospitalized ischemic strokes met inclusion criteria, and of these strokes, 554 (1.5%) had at least 1 episode of ILI in the 365‐day risk period prior to their stroke. Using non‐overlapping time intervals from ILI to stroke, the odds of ischemic stroke was greatest in the first 15 days post ILI (OR: 2.88, 95% CI: 1.86–4.47). The strength of the relationship decreased as the time from ILI increased, and was no longer significant after 60 days. There was a significant interaction (P = 0.017) with age and ILI; the odds of stroke associated increased 7% with each 10‐year decrease in age (OR per 10‐year age decrease 1.07, 95% CI: 1.03–1.35).InterpretationWe found that ILI increases short‐term risk of stroke, particularly in people under the age of 45, and therefore may be considered to act as a trigger for stroke.

Severe Acute Respiratory Syndrome Coronavirus 2 Infection and Ischemic Stroke

“…Infection increases the odds of stroke by 1.4-fold particularly early in convalescence. 4 A similar relationship might be expected from infection by the novel coronavirus SARS-CoV-2, which causes COVID-19.…”

Stroke and Novel Coronavirus Infection in Humans: A Systematic Review and Meta-Analysis

“…The pathophysiology for the development of stroke in patients with COVID-19 is multifactorial. Infection, in general, may increase the odds of stroke 1.4-fold, particularly in the early convalescence phase, and this association may also be similarly expected among COVID-19 patients ( 17 ). Secondly, SARS-CoV-2 may potentially predispose to thrombogenesis and increase the risk of stroke by infecting the myocardium cells via ACE2 (angiotensin-converting enzyme II) receptor and causing vascular injury and inflammation ( 18 ).…”

“…The association of stroke with viral infection is well-established, albeit uncommon. In general, viral infection, particularly those in the early convalescence phase, increases the odds of stroke by 1.4-folds ( 17 ). A previous study amongst SARS-COV-1 patients showed that LVO occurred in a small percentage of patients (2.4%) that were infected in which the two patients had cardiac dysfunction, disseminated intravascular coagulation, and significant hypotension before the onset of stroke ( 65 ).…”

Large vessel stroke in six patients following SARS‐CoV‐2 infection: a retrospective case study series of acute thrombotic complications on stable underlying atherosclerotic disease

“…Our observations illustrate large vessel occlusion associated with clotting induced by SARS-CoV-2 infection complicating underlying stable atherosclerotic disease. Complications of atherosclerotic disease by viral infection have previously been described [11,12] but the heavy burden of the current COVID outbreak has permitted an infrequent complication of atheroma associated with viral infection to be described. Direct (invasion by virus) or indirect mechanisms (inflammatory/procoagulant status) have also been debated [7,13].…”