Abstract 69: Does Advanced Imaging Delay Time to Administration of Intravenous rt-PA in the Acute Ischemic Stroke Patient?

Background: Faster administration of intravenous recombinant tissue plasminogen activator (IV rt-PA) is associated with better outcomes in acute ischemic stroke (AIS) patients. Cerebral imaging is essential to determine inclusion and exclusion criteria, yet there are no universal imaging protocols for the AIS patient. Furthermore, multimodal imaging can lead to longer times of acquisition and interpretation. We assess the change in treatment times in our institution before and after modification of our imaging protocol. Methods: We performed a retrospective analysis comparing time to Computed Tomography (CT) interpretation and time to IV rt-PA treatment in AIS patients at our institution for three months before and after implementing imaging protocol changes. We defined these groups as the multimodal imaging group which received Non-contrast Computed Tomography of the head (NCCTH), CT Arteriogram (CTA), and CT Perfusion (CTP), versus the NCCTH only group. We performed statistical analysis using Fisher exact test comparing treatment groups in goal time to CT interpretation (< 45 minutes from time of arrival to Emergency department (ED) to completion of CT interpretation) and rt-PA administration (< 60 minutes from time of arrival to ED to initiation of rt-PA infusion). Results: During the six month period, we identified 110 AIS patients who underwent activation of our emergent CT protocol. The multimodal group contained 43 patients while the NCCTH only group contained 67. The mean Time to CT interpretation was 130 (range 11-557) in the multimodal group vs. 87 (12-361) in the NCCTH only group with 16% vs. 37% receiving CT evaluation within 45 minutes of presentation (p=0.02). The mean Time to IV rt-PA administration was 72 minutes (range 19-138) in the multimodal group and 60 minutes (32-94) in the NCCTH only group with 29% vs. 50% receiving IV TPA within 60 minutes (p=0.02). Conclusion: The use of multimodal imaging may provide useful information for AIS treatments beyond IV rt-PA; however, such advanced imaging was a source of delay for treatment at our institution. Streamlining the imaging protocol at our institution has improved our achievement of rt-PA administration time goals.