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Updated: May 22, 2026
Optimized Management of Endovascular Treatment for Acute Ischemic Stroke
Published on: January 18, 2018
The Role of Stroke Severity in the Association between Hypoperfusion Intensity Ratio and Futile Reperfusion after
Liyuan Wang1, Ziqi Xu2, Hongjian Shen3
1Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.
Introduction:
The hypoperfusion intensity ratio (HIR) was significantly correlated with the futile reperfusion (FR) and National Institutes of Health Stroke Scale (NIHSS) score. We aimed to quantify the direct and indirect effect of HIR on FR.
Methods:
We analyzed acute ischemic stroke patients with large vessel occlusion who underwent endovascular treatment at seven comprehensive stroke centers between 2017 and 2022 in China. HIR was automatically calculated on baseline perfusion imaging as the ratio of brain volume with time-to-max (Tmax) delay >10 s over volume with Tmax >6 s. The established threshold HIR >0.4 was regarded as poor tissue-level collaterals (TLCs). FR was defined as the modified Rankin Scale score of 4-6 at 90 days despite successful recanalization. Mediation analysis using the "mediation" package in R 4.2.2 was performed to examine the potential causal chain.
Results:
Among the 891 included patients, FR was observed in 320 (35.9%) patients. Inadequate TLC was significantly associated with a higher NIHSS score (adjusted common odds ratio [OR], 1.47; 95% confidence interval [CI], 1.12-1.93; p = 0.006) and higher rates of FR (aOR, 1.87; 95% CI, 1.31-2.68; p = 0.001) within 90 days. The baseline NIHSS score was a predictor of FR (aOR, 1.13; 95% CI, 1.10-1.16; p < 0.001). Causal mediation analyses revealed that 20.4% (95% CI, 5.5%-40.9%) of the relationship between HIR and FR was mediated by the baseline NIHSS score.
Conclusion:
Higher NIHSS score partially mediates the association between poorer HIR and FR at 90 days among patients after EVT. Our study provided primarily mechanistic and prognostic findings about the effect of HIR on FR.
