Hypoperfusion index ratio and pretreatment with intravenous thrombolysis are independent predictors of good functional outcome in acute ischemic stroke patients with large vessel occlusion treated with acute reperfusion therapies.

Introduction: We aimed to investigate the performance of several neuroimaging markers provided by perfusion imaging of Acute Ischemic Stroke (AIS) patients with large vessel occlusion (LVO) in order to predict clinical outcomes following reperfusion treatments.

Methods: We prospectively evaluated consecutive AIS patients with LVO who were treated with reperfusion therapies, during a six-year period. In order to compare patients with good (mRS scores 0-2) and poor (mRS scores 3-6) functional outcomes, data regarding clinical characteristics, the Alberta Stroke Programme Early Computed Tomography Score (ASPECTS) based on unenhanced computed tomography (CT), CT angiography collateral status and perfusion parameters including ischemic core, hypoperfusion volume, mismatch volume between core and penumbra, Tmax > 10 s volume, CBV index and the Hypoperfusion Index Ratio (HIR) were assessed.

Results: A total of 84 acute stroke patients with LVO who met all the inclusion criteria were enrolled. In multivariable logistic regression models increasing age (odds ratio [OR]: 0.93; 95%CI: 0.88-0.96, p = 0.001), lower admission National Institute of Health Stroke Scale (NIHSS)-score (OR: 0.88; 95%CI: 0.80-0.95, p = 0.004), pretreatment with intravenous thrombolysis (OR: 3.83; 95%CI: 1.29-12.49, p = 0.019) and HIR (OR:0.36; 95%CI: 0.10-0.95, p = 0.042) were independent predictors of good functional outcome at 3 months. The initial univariable associations between HIR and higher likelihood for symptomatic intracranial hemorrhage (sICH) and parenchymal hematoma type 2 (PH2) were attenuated in multivariable analyses failing to reach statistical significance.

Discussion: Our pilot observational study of unselected AIS patients with LVO treated with reperfusion therapies demonstrated that pre-treatment low HIR in perfusion imaging and IVT were associated with better functional outcomes.