Assessment of the National Institutes of Health Stroke Scale (NIHSS) score immediately following endovascular recanalization therapy (EVT) is more effective than evaluating baseline NIHSS score or revascularization status to determine 3-month neurologic outcome for patients who had a stroke and who have major occlusions in the anterior circulation and receive EVT, according to study findings published in Stroke.
In this single-center study, investigators retrospectively analyzed prospective data of people who had a stroke and received EVT (n=566). The investigators obtained participants’ baseline and post-EVT NIHSS scores and developed 4 different models for analysis. In the first model, investigators analyzed baseline predictors (ie, age, sex, premorbid modified Rankin scale [mRS], time from onset to EVT, use of recombinant tissue plasminogen activator, stroke location, stent-retrieve use, and initial glucose) as well as the initial NIHSS score to determine their relevance in predicting prognosis.
Additionally, models 2, 3, and 4 included modified Thrombolysis in Cerebral Ischemia (mTICI), post-EVT NIHSS, and mTICI plus post-EVT NIHSS scores, respectively, in addition to all predictors included in model 1. At 3 months following the index stroke, investigators prospectively collected mRS scores using either telephone interview or clinic visit. A score of 0 to 2 on the mRS, which is used to assess the degree of poststroke disability and/or dependence, was deemed a favorable outcome.
Overall, the median initial and post-EVT NIHSS scores were 14 (9-19) and 11 (5-17) points, respectively, representing a 58.8% improvement. At 3 months, models 3 and 4 demonstrated significantly increased discrimination power for the mRS score of 0 to 2 compared with models 1 and 2 (C statistics, 0.896 and 0.906 vs 0.802 and 0.834, respectively; P <.001). Among patients with successful recanalization (mTICI 2b or 3; 80.9% [n=458]), models 3 and 4 as well as the post-EVT NIHSS score demonstrated better performance than models 1 and 2; however, there was no additional discriminating value with the addition of mTICI grade in the models.
Because of the study’s retrospective design and the use of patient data from one center, the findings are limited in generalizability. Additionally, the investigators of this study evaluated patients who received care between 2008 and 2015, so findings may differ from those receiving care under the current EVT guideline from the American Heart Association Council published in 2015.
Based on the findings, the investigators “suggest that when evaluating the effect of adjuvant therapy or biomarkers on prognosis after EVT, post-EVT NIHSS score needs to be considered as another baseline neurological status.”
Jeong HG, Kim BJ, Choi JC, et al. Posttreatment National Institutes of Health stroke scale is superior to the initial score or thrombolysis in cerebral ischemia for 3-month outcome. Stroke. 2018;49(4):938-944.