Abstract TP69: Association Between DWI-FLAIR Mismatch and Functional Outcomes in Patients Undergoing Mechanical Thrombectomy

Abstract

Background and Purpose: Diffusion weighted imaging-fluid attenuated inversion recovery (DWI-FLAIR) mismatch was well recognized as an early sign of acute ischemic stroke lesions. In the era of mechanical thrombectomy (MT), DWI-FLAIR mismatch could be a good marker for candidates of MT. We thus investigated the association between DWI-FLAIR mismatch and functional outcomes in patients who received MT for acute large vessel occlusion (LVO). Methods: We conducted historical cohort study in consecutive patients who were evaluated by MRI for suspected stroke at single stroke center. We enrolled patients with occlusion of the ICA or M1 or M2 segment of MCA who were underwent MT within 24 hours after the last known to be well. FLAIR negative was defined when a visible acute ischemic lesion was present on DWI without traceable parenchymal hyperintensity on FLAIR. We estimated the adjusted OR of FLAIR negative for moderate outcome defined as mRS 0-3 at 90 days after onset. We also estimated the adjusted OR for symptomatic intracranial hemorrhage within 72 hours and mortality at 90 days. Results: Among 380 patients who received MT for acute LVO, 202 patients were included in this study. Patients with FLAIR negative was 146 (72%), and the rest were FLAIR positive. Patients with FLAIR negative had significantly higher baseline NIHSS (median 16 vs 13, p=0.01), more transferred-in (78% vs 63%, p=0.02), more intravenous thrombolysis (IVT) (45% vs 18%, P=0.0003), more cardioembolism (69% vs 54%, p=0.03), and shorter times from the onset to hospital door (median 175 vs 371 minutes, p<0.0001). Patients with FLAIR negative had more moderate outcome than the counterparts (61% vs 52%, p=0.24). The adjusted OR of FLAIR negative compared to positive was 2.97 (95%CI, 1.33-6.60, p=0.008). Symptomatic intracranial hemorrhage within 72 hours was less frequent in the FLAIR negative group (10% vs 20%, p=0.06), with an adjusted OR of 0.34 (95%CI, 0.13-0.87, p=0.02). Conclusions: DWI-FLAIR mismatch was associated with better functional outcome in patients received MT for acute LVO at 90 days. DWI-FLAIR mismatch should be a good marker for the candidate of MT for acute LVO. Future randomized trial to evaluate the effectiveness of MRI-based MT using DWI-FLAIR mismatch should be considered.