Abstract WP143: Use Of CTP For Evaluation Of EVT Candidates In The Early Time Window (<6 Hours From Lkwt) Does Not Delay EVT T And Use Of CTP Beyond 6 Hours Improves Speed Of EVT

Introduction: Computerized Tomography Perfusion (CTP) improves detection of distal occlusion and aids in patient selection for endovascular therapy (EVT) for acute ischemic stroke (AIS). As EVT continues to evolve, it is important to assess if CTP continues to aid in the evaluation of AIS or if it adds unnecessary time. Here we assess whether the imaging approach used to evaluate EVT patients was associated with improved door to device times or clinical outcomes. Specifically, we assessed whether CTA alone vs CTA/CTP combined had an effect on door to device (DTD) for EVT, discharge disposition and 90-day mRS. Methods: Data from 1357 AIS EVT patients from 17 hospitals was obtained from a multi-state health system’s stroke registry between Jan 1, 2018, to Apr 11, 2022. Multivariable mixed-effect linear and logistic regression models were employed to identify the association of evaluation type with DTD, discharge disposition and mRS, adjusting for age, sex, race, mode of arrival, NIHSS, stroke mechanism, medical history, and TICI score. Multivariable ordinal regression model was used with mRS as ordinal variable. Each clinical outcome was assessed for last known well (LKW) to arrival below 6 hours and between 6 and 24 hours. Results: The median age was 74 years, 729 (47.7%) were male; 958 (70.6%) arrived in less than 6 hours from LKW and 399 (29.4%) in the interval between 6 and 24 hours. CTA and CTP evaluation was used for 829 (61.1%) patients. In the multivariable models, evaluation with both CTA and CTP was significantly associated with a decrease of the DTD when LKW to arrival was > 6 hours (n= 955, regression coefficient -16, 95% CI -27, -3.6, p = .01) and had no effect on DTD inside of 6 hours. No significant association was found between evaluation type and discharge disposition or 90-day mRs after adjustment for covariates. Conclusions: In EVT patients presenting inside of 6 hours, addition of CTP to CTA caused no delay in DTD and in those presenting from 6-24 hours adding CTP shortened DTD by 16 minutes. This may reflect that CTP allows for more confident and expeditious treatment. These results along with no effect of evaluation type on clinical outcome argue that there is no disadvantage to the use of CTP inside of 6 hours and a clear time advantage beyond 6 hours.