O-014 Outcomes of mechanical thrombectomy in the early (<6 H) and extended time (≥6 H) window solely based on noncontrast CT and CT angiography

Abstract

<h3>Objective</h3> Current stroke care recommendations state patient selection for mechanical thrombectomy (MT) in the extended time window demand advanced imaging to determine the stroke core volume and hypoperfusion mismatch, which may not be available at every center. We aimed to determine outcomes in patients selected for MT solely based on non-contrast CT (NCCT) and CT-angiography (CTA) in the early (&lt;6 h) and extended (≥6 h) time windows. <h3>Methods</h3> Consecutive MTs performed for acute large vessel occlusion (LVO) ischemic (ICA, M1, M2) stroke between 02/2016- 08/2020 were retrospectively reviewed. Eligibility for MT was based on patient demographics and NCCT (ASPECTS), and CTA. Propensity score matching (PSM) was performed to compare outcomes between time windows. <h3>Results</h3> Out of 417 MTs performed, 337 met inclusion criteria resulting in 205 (60.8%) and 132 (39.2%) cases in the 0-6 and 6-24 hour time windows, respectively. ASPECTS was higher in the early time window (9, IQR 8-10) than the extended time window (9, IQR 7-10; p=0.005). PSM yielded 112 well matched-pairs. Equal rates of TICI 2b/3 revascularization and symptomatic intracranial hemorrhage were observed. A favorable functional outcome (mRS 0-2) was numerically more frequent in the early window (45.5% vs. 33.9%, p=0.091). Mortality was more frequent in the early window (25.9% vs. 17.0%, p=0.096). <h3>Conclusion</h3> Withholding mechanical thrombectomy due to lack of advanced imaging may not be justifiable for those patients with favorable CT-ASPECTS irrespective of the time window of presentation. Additional investigation is required to determine the value of advanced imaging in the extended time window. <h3>Disclosures</h3> <b>P. Hendrix:</b> None. <b>D. Chaudhary:</b> None. <b>V. Avula:</b> None. <b>V. Abedi:</b> None. <b>R. Zand:</b> None. <b>A. Noto:</b> None. <b>I. Melamed:</b> None. <b>O. Goren:</b> None. <b>C. Schirmer:</b> None. <b>C. Griessenauer:</b> None.