Abstract T P16: Indirect Comparison of Functional Outcomes in Stroke Patients Following Endovascular Versus Best Medical Treatment: Insights From Defuse 2 and Axis 2

Abstract

Background: Imaging based selection of acute ischemic stroke patients may improve clinical outcomes after endovascular therapy. DEFUSE 2 was a prospective cohort study of ischemic stroke patients who underwent a baseline MRI scan before endovascular therapy. In DEFUSE 2 reperfusion was associated with increased good functional outcome in patients with the target mismatch (TMM) profile, but not in patients without TMM. AXIS 2 was a randomized, controlled, MRI based trial of IV GM-CSF versus placebo. This study, in which endovascular therapy was not permitted, did not show improved functional outcomes between GM-CSF and placebo. We performed an indirect comparison between the outcomes seen in DEFUSE 2 and a control group from AXIS 2. Methods: Patients from AXIS 2 with a confirmed large vessel occlusion of the MCA or ICA on MR angiography, obtained within 9 hours after symptom onset, were selected as a control-group for patients from DEFUSE 2. The primary endpoint was good functional outcome at day 90 defined as a modified Rankin scale score of 0-2. Reperfusion status could only be assessed in the DEFUSE 2 cohort. We performed a stratified analysis based on the presence of TMM for both studies and reperfusion status in DEFUSE 2. Results: We compared good functional outcome in 102 patients (TMM in n=47, 49%) from AXIS 2 and 98 patients (TMM in n=78, 80%) from DEFUSE 2. After correction for differences in age, NIHSS and DWI volume, rates of good functional outcome were similar, 43% in DEFUSE 2 compared to 30 % in AXIS 2 (OR 0.9, 95%CI 0.5-1.7). In DEFUSE 2 patients with the TMM profile in whom reperfusion was achieved, the rate of good functional outcome was increased compared to TMM patients in AXIS 2, 64% versus 32% (OR 3.2, 95%CI 1.2-8.4). In TMM patients from DEFUSE 2 without reperfusion, the rate of good functional outcome was similar (31%), to the TMM patients in AXIS 2 (OR 1.0, 95%CI 0.4-2.3). No difference in outcomes was observed regardless of reperfusion status when a TMM was not present. Conclusion: This indirect, controlled comparison suggests that endovascular treatment resulting in reperfusion may lead to improved outcomes in patients with the TMM profile.