Abstract WP61: Union of Ischemic Core and Hypoperfusion Volume Correlates With 24-hour Infarct Size in DEFUSE 3

Background and Purpose: Accurate prediction of 24-hour infarct volume early after stroke onset helps determine appropriate interventions and prognosis. In the Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke (DEFUSE 3) trial, we evaluated the accuracy of early ischemic core and hypoperfusion volumes for predicting infarct volume 24 hours after randomization to endovascular thrombectomy vs. medical management. We also assessed if the volume of persistent hypoperfusion at 24 hours predicts infarct volume. Methods: Patients in DEFUSE 3 with CT or MRI DWI/perfusion imaging acquired at baseline and at 24 hours after randomization were included. Ischemic core and Tmax>6s hypoperfusion volumes at baseline and 24 hours were calculated using RAPID software and compared with the 24-hour infarct volumes. Patients were stratified by reperfusion status for analyses. Results: Of 125 eligible patients, 59 patients with >90% reperfusion had a strong correlation between baseline ischemic core volumes and 24-hour infarct volume (r = 0.83; p < 0.0001), and 14 patients with <10% reperfusion had a strong correlation between baseline Tmax>6s volume and 24-hour infarct volume (r = 0.77; p < 0.001). In the 52 patients with 10-90% reperfusion, as well as in all 125 patients, the union of the baseline ischemic core and the Tmax>6s perfusion volume at 24 hours was highly correlated with 24-hour infarct volume (for N=125, r = 0.83; p < 0.0001), with a median absolute difference of 21.3 ml between observed and predicted infarct volumes. Conclusions: The union of the irreversibly injured ischemic core and critically hypoperfused tissue volumes, as identified by CT perfusion or MR DWI/perfusion, predicted infarct volume at 24 hours in DEFUSE 3 patients. Clinical Trial Registration - URL: http://www.clinicaltrials.gov. Unique identifier: NCT02586415