Abstract WP49: Mri Based Thrombolysis For Unwitnessed Stroke Patients Is Feasible At Primary Stroke Centers

Abstract

Background: The 2018 WAKE-UP Trial established the safety and efficacy of administering IV-tPA in patients who presented within 4.5 hours of symptom discovery based on specific MRI sequences. Implementation of the study results remains limited at Primary Stroke Centers (PSCs). We assessed the feasibility of a Comprehensive Stroke Center (CSC) MRI based unwitnessed thrombolysis protocol at 13 PSCs. Methods: A committee consisting of vascular neurologists, neuroradiologists and MRI technologists developed the protocol. The protocol was utilized at the CSC for one year, and subsequently expanded to the PSCs. A specific "WAKE-UP MRI”" order was created which consisted of only DWI, GRE and FLAIR sequences. MRI technologists were trained to ensure that the "WAKE-UP MRI” would take priority over other patients; eg: if there was no one in MRI, it would be held for the stroke patient, and if MRI was occupied, the stroke patient would be next. The acute stroke care was managed by an integrated telestroke system at the PSCs. All telestroke providers were educated on the protocol. Standard stroke time metrics were collected and analyzed over 2 years. Data from the CSC was compared with its 13 PSC spokes. A student’s t-test was used for data analysis. Results: A total of 190 patients who arrived with 4.5 hours of symptom discovery were screened; 62 at CSC and 128 at PSCs. Forty underwent emergent MRI at CSC and 29 at PSCs. Median door to MRI time was longer for patients presenting to PSC compared to CSC (78 vs 53.5 mins; p = 0.0002). Twenty-one vs 9 patients received tPA at CSC and PSC hospitals respectively. Median door to needle (DTN) times were longer for patients at PSC vs CSC (106 vs 67 mins; p = .018). The most common reasons for not administering IV-tPA was a negative MRI (40% at PSCs vs 47% at CSC) and a lack of DWI and FLAIR mismatch (40% at PSCs vs 42% at CSC). Conclusion: Use of emergent MRI in unwitnessed stroke for thrombolysis is feasible at PSCs. There remain barriers to implementation, with PSCs showing more delayed access to MRI and thrombolysis compared to CSC.