Abstract TMP91: Clinical Change During Inter-Hospital Transfer for Thrombectomy: Incidence, Associated Factors and Relationship With Outcome

Abstract

Background: Patients with acute ischemic stroke harboring a large vessel occlusion (LVO) admitted to non endovascular-capable centers often require inter-hospital transfer for thrombectomy. We aimed to describe the incidence of substantial clinical change during transfer, the clinical and imaging factors associated with change, and its relationship with 3-month outcome. Methods: We analyzed data from two prospectively collected cohorts of acute stroke patients transferred for thrombectomy to a comprehensive center (Stanford, USA, Nov 2019-Jan 2023; Montpellier, France, Jan 2015-Jan 2017). Patients were included if they had evidence of an LVO at the referring hospital and had an NIHSS score documented before and immediately after transfer. Inter-hospital clinical change was categorized as improvement (>=4 points and >=25% decrease between the NIHSS score in the referring hospital and upon comprehensive center arrival), deterioration (>=4 points and >=25% increase), or stability (neither improvement nor deterioration). The stable group was considered as the reference, and was compared to the improvement or deterioration groups separately. Results: A total of 504 patients were included, of whom 22% experienced inter-hospital improvement, 14% deterioration, and 64% were stable. Pre-transfer variables independently associated with clinical improvement were intravenous thrombolysis use, more distal occlusions, and lower serum glucose; variables associated with deterioration included more proximal occlusions and higher serum glucose. On post-transfer imaging, clinical improvement was associated with arterial recanalization and smaller infarct growth; and deterioration with larger infarct growth. As compared to stable patients, those with clinical improvement had better 3-month functional outcome (adjusted common OR=2.39; 95%CI=1.57-3.64), while those with deterioration had worse outcome (adjusted common OR=0.56, 95%CI=0.34-0.92). Conclusion: Substantial inter-hospital clinical changes are frequently observed in LVO-related ischemic strokes, with significant impact on functional outcome. There is a need to develop treatments that improves the clinical status during transfer.