Objective: This study aims to describe the relationship between CT perfusion-to-reperfusion time and the probability of functional independence in a cohort of patients undergoing endovascular therapy for acute ischemic stroke.
Methods: We included data from the CT Perfusion to predict Response in Ischemic Stroke Project (CRISP) in which all patients underwent a baseline CT perfusion (CTP) scan prior to endovascular therapy. Patients were included if they had a mismatch on their baseline CT perfusion scan and achieved successful endovascular reperfusion. Patients with mismatch were categorized into ‘target mismatch’ and ‘malignant mismatch’ profiles, according to the volume of their Tmax>10s lesion volume (target mismatch <100 mL; malignant mismatch >100 mL). We investigated the impact of CTP-to-reperfusion times on probability of achieving functional independence (mRS 0-2) at day 90 and radiographic outcomes at day 5.
Results: Of 156 included patients, 108 (59%) had the target mismatch profile, and 48 (26%) had the malignant mismatch profile. In patients with the target mismatch profile, CTP-to-reperfusion time showed no association with functional independence (p=0.84), whereas in patients with malignant mismatch profile, CTP-to-reperfusion time was strongly associated with lower probability of functional independence (OR=0.08, p=0.003). Compared to patients with target mismatch, those with the malignant mismatch profile had significantly more infarct growth (90 [49-166] vs. 43 [18-81] mL, p=0.006) and larger final infarct volumes (110 [61-155 vs. 48 [21-99] mL, p=0.001]).
Conclusion: Patients with the target mismatch and malignant mismatch profile respond differently to time delays between baseline imaging and endovascular reperfusion; those with the malignant profile demonstrate a more rapid decline in favorable clinical outcomes and have greater infarct growth.