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Abstract WMP23: Likelihood of Undergoing Endovascular Stroke Therapy in Centers With High vs Low Utilization of CT Perfusion Imaging


 Introduction:
 CT Perfusion (CTP) is frequently used to evaluate patients with large vessel occlusion (LVO) acute ischemic stroke (AIS) for possible endovascular stroke therapy (EST). However, the accuracy of its infarct core and penumbral predictions are uncertain, and as such, may rule out patients who would otherwise have received EST without CTP-based selection.
 
 
 Methods:
 From our prospectively maintained multicenter registry, we identified AIS patients between January 2018 and February 2019. Data were collected from 4 comprehensive stroke centers - one center often performs CTP on nearly all AIS evaluations (CTP-H) and 3 centers perform CTP for uncertain findings on non-contrast CT (CTP-L). All 4 CSCs are covered by a single group of Vascular Neurologists and NeuroInterventionists with standardization of quality practices. Logistic regression adjusted for age, NIHSS, CT ASPECTS as ordinal variables, time of presentation (0-6 hrs. vs 6-24 hrs.), and occlusion location was used to assess the likelihood of undergoing EST. Results are provided as median [IQR] and OR [95% CI].
 
 
 Results:
 Among 2,317 patients with AIS, median age was 67 [57-78], 48% were female and 48% were white. The CTP rates at the 3 CTP-L centers were 18%, 31%, and 36%, while CTP rate at CTP-H center was 74% among all AIS patients (p<0.0001). 309 (43%) patients with LVO presented to CTP-L centers and 404 (57%) to the CTP-H center. For LVO patients presenting at CTP-L centers, median age was 70 [60-80], 52% were female, and 42% were white, while at CTP-H center median age was 68 [59-78], 44% were female and 57% were white. ASPECTS scores (CTP-L 9 [7-10] vs CTP-H 8 [6-9], p>0.05) and proportion of ICA/MCA occlusions (72% vs 77%; p>0.05), were comparable among centers, but LVO patients presenting at CTP-L centers had a lower NIHSS (11[4-18] vs 14[7-20]; p<0.01). For patients presenting 0-6 hrs, a higher number presented at the CTP-H center (20% vs 27%; p<0.05). In adjusted logistic regression, patients presenting with LVO to the CTP-H center were less likely to undergo EST (OR 0.51 [0.29-0.89]; p<0.05).
 
 
 Conclusion:
 In this study of 4 CSCs staffed by the same group of physicians, routine utilization of CTP in EST patient selection was associated with reduced likelihood of EST in patients with LVO.
