Abstract 189: STAR: CT and MR Perfusion Imaging and Good Outcomes in Endovascular Stroke Treatment

Abstract

Background: Perfusion imaging may be used to select stroke patients for endovascular treatment, although few data are available on studies of CT and MRI, as used in Solitaire Flow Restoration Thrombectomy for Acute Revascularization (STAR), a prospective, multicenter, single-arm trial. Methods: The CT/MRI core lab processed available CT and MR perfusion source images with Olea Sphere 2.2 to measure volumes of infarct core and hypoperfusion. Established definitions for CT and MRI (core: rCBF < 31% (CT); ADC < 600х10 -6 mm 2 /s (MRI); hypoperfusion: Tmax > 6s (CT and MRI)) were used to provide equivalent measures. Core and hypoperfusion volumes, mismatch ratio and DEFUSE-2 categories of target and malignant profile were used to define the relationship of perfusion imaging with clinical outcomes. Results: 87 of 202 cases in STAR (mean age 68.7 ± 12.5 years; 57% women; median baseline NIHSS 15 (8-25)) had CT (60/87 or 69%) or MRI (27/87 or 31%) perfusion imaging processed. This cohort was similar to other STAR cases with mean time to treatment of 263 ± 95 min and IV tPA before thrombectomy in 55%. Infarct core volume was mean 11.2 ± 19.7 (0-116.9) cc with hypoperfusion volume of mean 70.6 ± 46.0 (0-182.2) cc. Mismatch ratio was mean 17.8 ± 53.7. 75/87 (86%) cases were categorized as target mismatch and only 5/87 (6%) as malignant profile. 58/87 patients (67%) had a mRS of 0, 1, or 2 at 90 days and 39/87 (45%) with a mRS of 0 or 1. Multivariate logistic regression identified that age (OR 0.91, p=0.010), time to treatment (OR 0.23, p=0.001), and Tmax > 10 s volume (OR 0.96, p=0.003) were associated with good outcomes (mRS 0-2 at 90 days). Only 2/87 (2.3%) patients had symptomatic ICH. Target mismatch exhibited a trend for good outcomes (p=0.149). Conclusions: STAR enrolled subjects with small infarct cores and extensive mismatch, achieving good clinical outcomes in a majority of cases treated with endovascular therapy. Randomized trials using CT and MR perfusion imaging are warranted to assess the impact of current endovascular stroke treatments.