Abstract Number ‐ 278: Transient Ischemic Attack Evaluation Pathways: Inpatient Versus Expedited Outpatient Comparative Analysis
Authors: Parikh Parth P , Chaudhary Hira , Alhayek Nour , Kelly Juli , Butterfield Brandi , Urumov Andrej , Demaerschalk Bart , Dumitrascu Oana 
Published: April 2023

Introduction
Transient Ischemic Attack (TIA) evaluation requires urgent etiology identification and targeted stroke prevention, traditionally performed via hospital admission. The literature suggests that outpatient evaluation may be safe and cost‐effective. Hence, we implemented an expedited outpatient pathway (OP) for patients presenting to our institution’s Emergency Department (ED) with TIA. To further guide future practice, we compared clinical features and outcomes between expedited OP and our well‐established inpatient pathway (IP).

Methods
We implemented an algorithm of direct communication between ED providers and Vascular Neurologists for all TIA patients. Certain screening studies (head CT, CT angiogram, basic laboratories) and acute therapies were implemented in the ED, whereas others (brain MRI, echocardiogram, etc) and Vascular Neurology consultations were expedited outpatient within 48–72 hours.We included all patients that underwent OP evaluation from May 2021‐May 2022. Further, we extracted patients with a final diagnosis of TIA and compared them with IP TIA patients hospitalized (2017‐2021), matched by age, gender, and clinical severity (ABCD2). Descriptive statistics were used to summarize patient demographics, clinical data, treatments, and 3‐month outcomes. Continuous variables were summarized with mean and standard deviations while categorical variables were shown as counts and percentages. Chi‐square test was used for categorical variables and Mann‐Whitney U test was used to compare continuous variables. P‐values < 0.05 were considered statistically significant and all tests were two‐sided. Statistical Analysis was completed in R 4.0.3.

Results
Of 43 patients who underwent expedited OP TIA workup, TIA or minor stroke was diagnosed in 21/43 (48.9%). 18 TIAs underwent comparative analyses. Mean symptom duration was longer in the IP (2.06 hours) than OP (0.99 hours), p = 0.370%. TIA was more likely to be diagnosed in the OP 14/18 (78%) versus IP 12/18 (67%), (p = 0.423). OP had more transesophageal echocardiograms (17% vs 5%, p = 0.630) and longer duration of ambulatory cardiac monitoring (mean 574.3 vs 381.7 hours, p = 0.100). IP patients were more likely to get started on anticoagulation compared to OP (38% vs 11%, p = 0.258) and high‐intensity statin (38% vs 17%, p = 0.260). All laboratories, echocardiograms and brain MR imaging were performed significantly sooner for the IP (p< 0.05 for all). IP had higher rate of return ED visits (22%) and readmissions at 3 months (11%), whereas OP had none. OP had no deaths or recurrent strokes, whereas 11% and 5.6% respectively were noted in the IP at 3 months (p = 0.310, p = 0.310).

Conclusions
Our study shows that routine IP evaluation for patients presenting with TIA in the ED may not offer diagnostic superiority nor lead to improvement of short‐term clinical outcomes, as compared to the expedited OP evaluation. Careful evaluation of TIA patients in the ED followed by expedited OP evaluation might be a plausible approach to help lower costs and avoid hospitalization without compromising the safety of these patients.