In a recent study published in Clinical Neurology and Neurosurgery, researchers evaluated the association of markers of inflammation and infection with mortality in individuals with acute ischemic stroke after thrombectomy.
Study: Markers of infection and inflammation are associated with post-thrombectomy mortality in acute stroke. Image credit: Gorodenkoff/Shutterstock
Large vessel occlusion (LVO) carries a high risk of morbidity/mortality and is seen in 20% to 40% of ischemic stroke cases. Clinical outcomes are significantly improved in those with LVO after thrombectomy. However, 15 to 20% of people with acute stroke die within three months of thrombectomy. Older age, increased infarct volume, and higher National Institutes of Health Stroke Scale (NIHSS) score at admission are factors that predict poor outcomes after thrombectomy.
Inflammation and infection could potentially contribute to poor outcomes after stroke. Infection can occur in up to 30% of hospitalized patients with ischemic stroke. Infection can exacerbate outcomes after stroke through systemic inflammation, leading to secondary neurological injury. Several studies have shown that poor functional outcomes after stroke are associated with elevated markers of inflammation. However, there are limited data on how inflammation and infection influence patient outcomes after thrombectomy.
About the study
In the present study, researchers characterized the association between markers of inflammation and infection and mortality in stroke patients after thrombectomy. They performed a retrospective chart review of patients admitted for acute ischemic stroke between December 2018 and November 2020. Subjects were included if thrombectomy was attempted independent of reperfusion and excluded if not.
Retrospective chart abstraction was performed to obtain demographic characteristics, stroke and hospitalization data such as admission NIHSS score, revascularization success, discharge mortality, and markers of inflammation and infection The Thrombolysis in Cerebral Infarction (TICI) score was used to measure the success of revascularization. A TICI score of 2c or 3 meant successful revascularization.
Markers of inflammation and infection included WBC count and percentage of neutrophils on admission, peak WBC count and fever during hospital stay, antibiotic treatment days, sputum culture data , blood and urine and the severe acute respiratory syndrome coronavirus (SARS-CoV-2). ) exam results. Infarct burden was assessed on non-contrast computed tomography (CT) scans of the head obtained postoperatively by a neurologist using the Alberta Stroke Program Early CT Score (ASPECTS).
The association of discharge mortality with demographic characteristics, stroke data, and markers of inflammation/infection was assessed using Fisher’s exact test or Student’s t test; the Wilcoxon rank sum test was used in the case of non-normally distributed variables. Multivariable regression analyzes tested for independent predictors of mortality. As a secondary analysis, the analyzes were repeated, excluding patients with coronavirus disease 2019 (COVID-19).
discoveries
There were 248 patients who met the inclusion criteria and 41 (17%) died before discharge. Fourteen patients tested positive for SARS-CoV-2 and were excluded from secondary analysis. In the primary (non-COVID-19) cohort, 34 patients died before discharge. Patients discharged alive had lower NIHSS scores on admission and were younger and less likely to have postoperative ASPECTS less than 8.
There was a significant association of discharge mortality with a higher mean white blood cell count, percentage of neutrophils, peak white blood cell count, and fever on admission. The results of the secondary analysis were similar, except for the leukocyte count on admission. In addition, patients who died before discharge were more likely to have a positive sputum, blood, or urine culture.
Nineteen patients had positive cultures, with sputum cultures (positive) accounting for about 95% of them. In addition, patients who died were treated with antibiotics for longer than those discharged alive. SARS-CoV-2 infection was also associated with an elevated risk of mortality. Seven patients with COVID-19 (50%) died before discharge.
Secondary analysis revealed associations between positive cultures and number of days of antibiotic treatment with discharge mortality. Multivariable analyzes indicated a significant association of discharge mortality with white blood cell count, neutrophil percentage, peak white blood cell count, fever, and positive culture.
Multivariable analysis excluding patients with COVID-19 showed a significant association of discharge mortality with fever, peak white blood cell count, and positive culture. The results of the multivariable analysis were similar when those with posterior circulation stroke were excluded (because ASPECTS is not relevant for these patients).
Conclusions
In summary, the authors noted that discharge mortality in patients with acute ischemic stroke after thrombectomy is associated with markers of inflammation and infection, independent of age, admission NIHSS score, and ASPECTS. Study limitations include a small cohort size with patients from a single city. However, the observed mortality rate approximates the expected mortality rate after thrombectomy.
In general, inflammation and infection after thrombectomy in patients with acute ischemic stroke portend a high risk of discharge mortality. These results underscore the need to identify modifiable markers of inflammation and infection and further elucidate the mechanisms of post-stroke neurological injury and inflammation to improve clinical outcomes.