Abstract T MP74: The Diagnosis, Etiologic Classification, and Safe Discharge of Ischemic Strokes with Transient Symptoms from an Emergency Department Observation Unit

Background: Patients with a clinical diagnosis of transient ischemic attack (TIA) who have imaging evidence of infarction portend a high risk of short-term recurrent stroke. Emergency Department Observation Units (EDOU) offer an alternative to hospital admission and are becoming increasingly utilized for acute cerebrovascular emergencies. Hypothesis: We sought to determine whether an EDOU protocol emphasizing etiologic determination and individualized secondary prevention could be a safe alternative to hospital admission for suspected TIA patients with and without brain infarction. Methods: We prospectively studied 189 patients admitted to the TIA EDOU of a single tertiary care academic medical center. There was no ABCD2 cutoff for eligibility and exclusion criteria included persistent deficits or another diagnosis warranting hospitalization. Patients underwent DW-MRI/MRA of the head and neck unless contraindicated, transthoracic echocardiogram and bedside neurologist evaluation. Etiologic subtyping was determined using the Causative Classification System (CCS). 30-day follow-up was performed on all patients by telephone and/or review of medical records. This study was approved by the hospital IRB. Results: Acute ischemic stroke was diagnosed in 31 (16%) of patients, including 30 with DWI lesions and 1 in whom MRI was contraindicated, but had clinical worsening while in the EDOU. An evident or probable etiology was determined by CCS subtyping in 38% of strokes and 32% of TIAs (17% atherosclerosis, 12% cardioembolism, 5% small vessel). Of the total cohort, 84% were discharged from the EDOU including 16 (52%) with confirmed stroke. Median LOS was 22 hours (IQR: 17-25). At 30 days, one patient was found to have a small recurrent stroke (0.7%). There was 1 non-stroke related death. Twenty (11%) overall returned to the ED, the vast majority (70%) from the non-stroke cohort. Conclusions: Not all ischemic stroke patients require hospitalization. An EDOU is a safe and effective alternative for the complete diagnostic evaluation and management of patients with transient neurologic symptoms. Further study of cost and quality effectiveness in warranted.