Can CT Perfusion Identify Patients Unlikely To Show Improvement Following Intravenous Thrombolysis? (P4.226)

Objective/Background: CT perfusion (CTP) imaging has been performed in AIS patients to help determine eligibility for endovascular treatment, and has shown promise in selecting patients who might benefit from IV-tPA beyond 4.5 hours. We therefore wondered whether CTP could also identify patients who are less likely to benefit from IV-tPA within the thrombolytic window. Design/Methods: Patients with anterior circulation stroke who underwent CTP and received IV-tPA at a single tertiary care institute between 07/2009-12/2012 were included. Improvement was defined as “NIHSS improvement 蠅 4 or change to 0 or 1”. Neurological improvement post IV-tPA was assessed immediately, at 24 hours, and at 7 days (or discharge/death if earlier). CTP parameters including relative Cerebral Blood Volume (rCBV), relative Cerebral Blood Flow (rCBF), relative Mean Transit Time (rMTT), and ratio of Penumbral to Ischemic volume (P:I) were correlated with NIHSS at various time points after IV-tPA. Results: A total of 109 patients with median age 74 years (IQR 63-84) and median NIHSS 10 (IQR 6-19) met inclusion criteria. ROC analysis determined ideal thresholds for P:I, rMTT, and rCBV for lack of improvement immediately after IV-tPA (≤0.85, 蠅1.77, ≤1.02); within 24 hours after IV-tPA (≤0.78, 蠅1.55, ≤0.94), and at 7 days or discharge (≤0.83, 蠅1.75, ≤0.87). P:I was significant within 24 hours and at 7 days; rMTT was significant immediately after IV-tPA and at 24 hours; rCBV was significant at 24 hours and at 7 days. Multivariate analysis (adjusting for NIHSS, age and time from onset) found similar results. Conclusions: PCT has potential to identify AIS patients that are less likely to improve with IV-tPA during hospital admission. This may have implications for early determination of resource utilization and care pathways. Further studies are required to determine whether PCT can similarly predict long term outcomes post IV-tPA. Disclosure: Dr. Damania has nothing to disclose. Dr. Kung has nothing to disclose. Dr. Koch has nothing to disclose. Dr. Jain has nothing to disclose. Dr. Jain has nothing to disclose. Dr. Jahromi has nothing to disclose.