Inflammation and infection after ischemic stroke are known to exacerbate tissue injury and worsen clinical outcome. Thrombectomy has become standard of care in stroke, but little data exist regarding how inflammation affects outcome after thrombectomy.

We performed retrospective chart review of stroke patients who underwent mechanical thrombectomy at 2 tertiary academic centers between December 2018 and November 2020. The relationship between discharge mortality, admission WBC count, admission neutrophil percentage, peak WBC count, and fever (peak temperature >38°C) were analyzed using the Wilcoxon rank sum test, Student’s t-test, and Fisher’s exact test. Multivariable analysis was performed to test for independent predictors of discharge mortality. Analyses were performed for the entire cohort, then repeated in a cohort excluding COVID-positive patients.

Of 254 patients who had thrombectomy for acute stroke, 42 (16.5%) died prior to discharge. Mortality was associated with admission WBC count (10.7 [8.9-14] vs. 8.6 [7-12], p=0.0064), admission neutrophil percentage (78% ± 11 vs. 70% ± 14, p=0.0001), peak WBC count (17 [13-22] vs. 12 [8.9-15], p<0.0001), and fever (71% vs. 29%, p<0.0001). In multivariable analysis, admission WBC count (OR 14, CI 1.5-158, p=0.024), neutrophil percentage (OR 1.04, CI 1.0-1.1, p=0.039), peak WBC count (OR 343, CI 27-5702, p<0.0001) and fever (OR 8.6, CI 3.6-23, p<0.0001) were significantly predictive of discharge mortality after controlling for age, admission NIHSS and post-thrombectomy ASPECTS score. Fifteen patients tested positive for COVID-19. In analyses excluding these patients, peak WBC count and fever remained independent predictors of discharge mortality.

Elevated markers of inflammation during hospitalization predict discharge mortality in patients who undergo mechanical thrombectomy for acute stroke. Further study is warranted to investigate causation and identify opportunities to improve quality of care in this patient population.