Factors associated with unfavorable outcome after anterior circulation stroke despite successful reperfusion and early neurological improvement

Background and Purpose: Successful reperfusion during endovascular therapy (EVT) usually leads to early neurological improvement (ENI), yet some patients do not achieve good longterm outcome. The aim of this study was to investigate factors associated with unfavorable clinical outcome (UCO) despite ENI. Methods: This was a retrospective singlecenter analysis of consecutive patients treated for anterior circulation large vessel occlusion who achieved successful reperfusion and ENI (at least 20% lower followup NIHSS compared to NIHSS on admission) between 01/2014 and 04/2019. The primary endpoint was unfavorable outcome (90d mRS > 2 or mRS > baseline mRS). Patients with favorable clinical outcome (FCO) and UCO despite ENI were compared in univariable regression analysis. Results: Successful EVT (mTICI 2c or 3) and ENI occurred in 396/549 (72.1 %) patients and unfavorable outcome despite ENI in 168/396 (42.2 %) patients. Factors associated with UCO were baseline mRS (Odds ratio (OR) 3.13, p < 0.001), age (OR 1.09, p < 0.001), baseline NIHSs (OR 1.09, p < 0.001), female sex (OR 1.92, p = 0.002), hypertension (OR 2.32, p = 0.002), smoking (OR 0.48, p = 0.019), history of previous stroke (OR 2.7, p < 0.001), atrial fibrillation (OR 1.73, p = 0.007), neutrophil-lymphocyte ratio (OR 1.05, p = 0.014), as well as ASPECTS after EVT (OR 0.77, p < 0.001), TAN score (OR 0.60, p < 0.001) and Swieten score (OR 2.55, p < 0.001). Several ASPECTS regions were associated with UCO despite ENI (insula, M1-M3 and M5). Conclusions: Relevant factors associated with UCO despite successful EVT and ENI were patient age, sex, baseline mRS, hypertension, history of smoking, previous stroke, atrial fibrillation, neutrophil-lymphocyte ratio, TAN and Swieten Score as well as ASPECTS after EVT. The involvement of certain brain regions by ASPECTS segments were associated with UCO despite ENI after EVT. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study did not receive any funding ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Ethics committee of Medical Faculty University Hospital Heidelberg (Germany) gave approval for this work. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present work are contained in the manuscript