Background Favorable imaging profile according to the Alberta Stroke Program Early CT Score (ASPECTS) on noncontrast head CT is a key criterion for the selection of patients with ischemic stroke from large vessel occlusion (LVO) for intra-arterial (IA) revascularization therapies.

Objective The goal of our study was to analyze factors associated with changes in ASPECTS during inter-hospital transfer and to determine their impact on eligibility for endovascular procedures.

Methods We analyzed factors associated with changes in ASPECTS during inter-hospital transfer and their potential impact on eligibility for IA stroke therapies in patients with anterior circulation ischemic strokes. Clinical and demographic characteristics between patients with favorable and unfavorable imaging on repeat CT were compared. Favorable ASPECTS profile was defined as ASPECTS ≥6, and unfavorable ASPECTS <6, based on the imaging criteria proposed by the AHA in the 2015 updated acute stroke guidelines.

Results Of the 50 transferred patients with anterior circulation LVO, 42 had favorable ASPECTS ≥6 on CT imaging performed at outside hospital. 19 (45%) of those 42 patients presented to an outside facility within 6 hours of stroke onset (mean time from symptom onset to head CT, 295 ± 61 min), whereas in 23 patients CT showed favorable ASPECTS with stroke onset beyond the 6 hour window (mean time from symptom onset to outside CT, 603 ± 224 min). Stroke evolution towards unfavorable ASPECTS occurred in 13 (31%) out of 42 patients who initially had favorable imaging profile at outside hospitals. Higher NIHSS score was the only significant predictor of ASPECTS decay, whereas other clinical characteristics such as the use of intravenous thrombolysis and site of LVO (ICA versus MCA M1/M2) were similar between both groups.

Conclusions Our study showed that during inter-hospital transfer, one out of three patients with stroke from anterior circulation LVO becomes ineligible for IA thrombectomy based on CT ASPECTS imaging criteria alone. Except for NIHSS severity, no other baseline clinical factors could identify which patients were at risk of ASPECTS deterioration. Our study indicates the critical importance of rapid transfer of all stroke patients with suspected LVO to endovascular-capable hospitals.

Disclosures M. Mokin: None. R. Gupta: 1; C; Zoll, WellStar foundation. 2; C; Stryker Neurovascular, Covidien, Penumbra, Rapid medical. 6; C; Penumbra, Inc. W. Guerrero: None. D. Rose: 3; C; Boehringer Ingelheim Pharmaceuticals, Chiesi-USA. W. Burgin: None. S. Sivakanthan: None.