ASPECTS, Large Vessel Occlusion, and Time of Symptom Onset: Estimation of Eligibility for Endovascular Therapy.

BACKGROUND: Understanding how many patients are eligible for endovascular therapy can help develop more effective stroke systems of care. OBJECTIVE: To determine the proportion of patients eligible for endovascular therapy. METHODS: In this single center retrospective cohort study, we identified patients with acute ischemic stroke from large vessel occlusion (LVO) from January 2014 to December 2015. Selection criteria including LVO location, Alberta stroke program early computed tomography score (ASPECTS) range, hospital arrival time, and the use of intravenous thrombolysis were applied to calculate proportions of patients eligible for endovascular therapy. RESULTS: Of 989 patients with acute ischemic stroke, LVO was identified in 224 (23%) cases. Eighty-four percent of patients admitted within 6 h, 75% of patients admitted within 6 to 12 h, and 77% of patients with M1 and internal carotid artery occlusions admitted within 12 to 24 h had favorable ASPECTS for thrombectomy, defined as ASPECTS ≥ 6. Severity of NIHSS (National Institutes of Health Stroke Scale) was predictive of favorable ASPECTS (odds ratio [OR] 0.20, 95% confidence interval [CI] 0.04-0.74; P = .014 for NIHSS > 10 and OR 0.30, 95% CI 0.12-0.80; P = .014 for NIHSS > 20), whereas time of hospital arrival was not (OR 1.73, 95% CI 0.76-4.03; P = .26). Using all class I, Level of Evidence A American Heart Association guidelines criteria, 4% of patients with acute ischemic stroke were eligible for endovascular therapy. Up to 20% of patients were eligible for endovascular therapy with less restrictive criteria (Class IIb; Level of Evidence C). CONCLUSION: Depending on the sets of selection criteria, between 4% (the most restrictive criteria) and 20% (the least restrictive criteria) of patients with LVO are potentially eligible for endovascular therapy.

ASPECTS decay during inter-facility transfer in patients with large vessel occlusion strokes.

BACKGROUND: Favorable imaging profile according to the Alberta Stroke Program Early CT Score (ASPECTS) on non-contrast head CT is a key criterion for the selection of patients with ischemic stroke from large vessel occlusion (LVO) for IA revascularization therapies. OBJECTIVE: To analyze factors associated with changes in ASPECTS during inter-hospital transfer and to determine how deterioration of ASPECTS affects 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 (ASPECTS ≥6) and unfavorable (ASPECTS <6) imaging on repeat CT were compared. RESULTS: Stroke evolution towards unfavorable ASPECTS occurred in 13/42 (31%) patients who initially had a favorable imaging profile at outside hospitals. A higher National Institutes of Health Stroke Scale (NIHSS) score was the only significant predictor of ASPECTS decay, whereas other clinical characteristics, such as the use of IV thrombolysis and site of LVO, were similar between the two groups. CONCLUSIONS: In our cohort, one out of three patients became ineligible for IA thrombectomy because of unfavorable ASPECTS 'decay' following inter-hospital transfer. Except for NIHSS severity, baseline clinical factors could not identify which patients were at risk for ASPECTS deterioration.