Predictors of futile recanalization in ischemic stroke patients with low baseline NIHSS.

Background

There is yet no randomized controlled evidence that mechanical thrombectomy (MT) is superior to best medical treatment in patients with large vessel occlusion but minor stroke symptoms (National Institutes of Health Stroke Scale (NIHSS) <6). Prior studies of patients with admission NIHSS scores 6 observed unfavorable functional outcomes despite successful recanalization, commonly termed as futile recanalization (FR), in up to 50% of cases.

Aim

The aim of this study is to determine the prevalence of FR in patients with minor stroke and identify associated patient-specific risk factors.

Methods

Our multicenter cohort study screened all patients prospectively enrolled in the German Stroke Registry Endovascular Treatment from 2015 to 2021 (n = 13,082). Included were patients who underwent MT for anterior circulation vessel occlusion with a baseline NIHSS score of <6 and successful recanalization (modified Thrombolysis in Cerebral Infarction (mTICI) scores of 2b-3). FR was defined by modified Rankin Scale (mRS) scores of 2-6 at 90 days. Multivariable logistic regression analysis was conducted to explore factors associated with FR.

Results

A total of 674 patients met the inclusion criteria. FR occurred in 268 (40%) patients. Multivariable logistic regression analysis indicates that higher age (adjusted odds ratio (aOR) = 1.04 (95% confidence interval (CI) = 1.02-1.06)), pre-stroke mRS 1 (aOR = 2.70 (95% CI = 1.51-4.84)), transfer from admission hospital to comprehensive stroke center (aOR = 1.67 (95% CI = 1.08-2.56)), longer time from symptom onset/last seen well to admission (aOR = 1.02 (95% CI = 1.00-1.04)), MT under general anesthesia (aOR = 1.78 (95% CI = 1.13-2.82)), higher NIHSS after 24 h (aOR = 1.09 (95% CI = 1.05-1.14)), and symptomatic intracranial hemorrhage (aOR = 16.88 (95% CI = 2.03-140.14)) increased the odds of FR. There was no significant difference in primary outcome between achieving mTICI score of 2b or 3.

Conclusions

Unfavorable functional outcomes despite successful vessel recanalization were frequent in acute ischemic stroke patients with low NIHSS scores on admission. We provide patient-specific risk factors that indicate an increased risk of FR and should be considered when treating patients with minor stroke.

Data accessibility statement

The data that support the findings of our study are available on reasonable request after approval of the German Stroke Registry (GSR) steering committee.

COI Statement

Declaration of conflicting interestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: The authors declared the following potential conflicts of interest: F.F. reported receiving personal fees from Eppdata GmbH outside the submitted work. H.C.K. reported an ownership stake in Eppdata GmbH and compensation from Eppdata GmbH for consultant services outside the submitted work. G.B. reported receiving compensation as a speaker from Balt and personal fees from Eppdata GmbH outside the submitted work. C.T. reported receiving personal fees from Eppdata GmbH outside the submitted work. J.J.H. reported consulting for Medtronic and MicroVention and Medical and Scientific Advisory Board membership for iSchemaView. G.W.A. reported equity and consulting for iSchemaView and consulting from Medtronic. G.T. reported receiving personal fees from Acandis, Alexion, Amarin, Bayer, Boehringer Ingelheim, Bristol Myers Squibb/Pfizer, Daiichi Sankyo, Portola, and Stryker outside the submitted work. J.F. reported an ownership stake in Eppdata GmbH and grants and personal fees from Acandis, Cerenovus, MicroVention, Medtronic, Stryker, and Phenox and grants from Route 92 outside the submitted work. T.D.F. reported grants from the German Research Foundation (DFG) (project no. 411621970) and personal fees from Eppdata GmbH outside the submitted work. A.H., L.W., M.S., and C.H. reported no disclosure.

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