Abstract WP310: On versus Off-hour Intravenous Thrombolysis in Acute Ischemic Stroke Patients Treated via Telestroke: Impact on Long-term Functional Outcome

Introduction: Telestroke has expanded access to acute stroke care. Time of presentation to the emergency department affects the door to needle time (DTN) and may subsequently affect long-term outcome in acute ischemic stroke (AIS) patients assessed via telestroke. In this study, we assess whether DTN times and long-term functional outcome differ among AIS patients treated with IV tPA via telestroke during on-hours versus off-hours. Methods: All patients who received IV tPA through the Medical University of South Carolina telestroke network between January 2016 and December 2017 were analyzed. Primary outcome was 90-day Modified Rankin Scale (mRS), with mRS ≤2 considered a good functional outcome. Independent variables included time of presentation, age, race, sex, admission NIHSS, symptom onset to needle, and door to needle time. On-hours were defined as 8am-5pm monday - friday, and off-hours were 5pm-8am Monday-Friday, weekends and holidays. Chi-square and t-tests were used to compare differences among categorical and continuous baseline variables, respectively. Multivariable logistic regression was used to examine the relationship between tPA delivery time and 90-day mRS, adjusting for patient baseline characteristics. Results: During the study period, 223 (39%) AIS patients received IV tPA during on-hours and 349 (61%) during off-hours in our telestroke network. Baseline characteristics were similar, except that the off-hours group had more white patients (P=0.04), and longer tPA decision to administration time (P=0.006). On-hours mean DTN time was 57.3 minutes, as compared to 63.2 minutes during off-hours (P=0.017). Primary outcome was similar between the 2 groups (OR 1.088, 0.687-1.722). Conclusion: AIS patients who presented during off-hours and received tPA had a longer DTN time, but comparable long-term outcome after IV thrombolysis in our telestroke network. The findings need validation in other telestroke cohorts, with the aim of providing consistent 24-hour telestroke care.