Abstract 114: Aspects versus Perfusion in the Trevo Retriever Registry: Defining the Core on the Largest Scale to Date

Abstract

Background: Routine use of advanced imaging versus ASPECTS for imaging triage of endovascular thrombectomy candidates has not been evaluated on a large scale to date. Ischemic core may be defined by ASPECTS or perfusion imaging, yet these variable definitions likely reflect different pathophysiology as perfusion may fluctuate and ASPECTS lesions may be time-dependent. Methods: The Trevo Retriever Registry was a prospective, open-label, consecutive enrollment, multicenter, international registry with more than 65 enrolling sites worldwide. The Imaging and Angiography Core Lab systematically adjudicated more than 1,500 subjects, scoring ASPECTS and separately processing perfusion imaging. Ischemic core volume on perfusion imaging was defined as rrCBF<30% (CTP) and analyzed with respect to ASPECTS. Results: 488 subjects (68.3±14.4 years; 53.3% women; baseline NIHSS median 15 (10-19) with anterior circulation occlusions were evaluated with both ASPECTS and perfusion imaging prior to thrombectomy. Arterial occlusions included 87/487 (17.9%) ICA and 296/487 (60.8%) proximal M1 MCA, treated with thrombectomy at median 4.7 (3.3-7.9) hours from time last known well (TLKW). ASPECTS was median 8 (7-9) with ischemic core lesions of median 18 (4.9-39.2) cc. At-risk hypoperfusion (Tmax>6s) lesions were median 109.8 (62-156.9) cc. TLKW was associated with ASPECTS (r=-0.18, p<0.001) yet no time relationship was noted with either ischemic core or at-risk hypoperfusion on perfusion imaging. ASPECTS correlated modestly with perfusion imaging-derived ischemic core (r=-0.35, p<0.001) and at-risk hypoperfusion (r=-0.24, p<0.001). Post-procedure mTICI≥2b occurred in 448/488 (91.8%). Each increment in baseline ASPECTS was associated with an adjusted OR of 1.21 (95%CI (1.05-1.39), p<0.008 for good clinical outcomes (day 90 mRS 0-2), whereas the perfusion lesion volume for ischemic core and at-risk hypoperfusion did not predict outcomes. Conclusions: Largescale, systematic evaluation of ASPECTS and perfusion imaging prior to thrombectomy reveals discrepancy in the definition of ischemic core and the prediction of clinical outcomes after revascularization. ASPECTS is time-dependent, yet reliably predicts outcomes in routine clinical practice.